How to build your own wireless receiver and transmitter device? Use RF in your next embedded application design!

March 11th, 2006

RF Wireless Project, Receiver and Transmitter (RLP TLP315 MHz) with ATMega 32

Some time has passed since I wrote something for the site but it is really not my fault. The classes have started again and as always there is a great number of assignments and homework. However, I will stop bothering you with my problems, let’s get down to work. Today you cannot see an embedded device without RF (Radio Frequency) capabilities, without the option to transfer data wireless. So I decided to make a little project that can be understood, handled and implemented by everybody; simplicity rules. I will tell you a story about RF, if you don’t like reading it, then just skip the following paragraph.

The scientist who developed the first remote device was born in my region and his name was Nikola Tesla. I am sure everybody heard for Tesla’s Coil, AC current and he has invented much more of the things that we use today and cannot live without them, well at least some of us use the AC current in our households :-p. After the discovery by the Russian scientist Alexander Popov that data could be transferred through air, Tesla had decided to give it a try and to implement a remote control circuit. It was the time before the World War I, after developing first prototypes in his lab, in New York, he decided to make a public presentation of what could be accomplished. As every pioneer in any field he wasn’t understood by the people and had to deal with all kinds of reactions. He made a little boat that was the receiver and a remote control that was the transmitter. All the people were fascinated by what they saw, nobody had ever seen before somebody controlling something without touching it. Everybody considered him a wizard, not a scientist. He died as a poor man in a New Yorker hotel feeding pigeons without people knowing what kind of breakthrough he made for humanity. This is why I had to share the story because without people like Nikola Tesla who shared their knowledge and dedicated their life to make a better world you wouldn’t sit in front of your computer reading this. I think you understood the moral of the story, share your knowledge and never keep it for yourself only. I hope it will impact at least on some of you who read this.

RF Receiver and transmitter modules (TLP315 RLP315) compared with a 1 Euro coin
RF Transmitter & Receiver modules compared with 1 Euro coin

Time to continue, sorry to those who read the story and didn’t like it. The receiver and transmitter boards (RLP & TLP 315) are cheap RF modules manufactured by Laipac Technologies. A pair costs $11.95 at SparkFun Electronics. The frequency on which the receiver and transmitter pair works is 315 MHz, UHF (Ultra High Frequency) frequency range. I won’t explain how data is transferred through air. If you want to know more about RF and how data is transferred through air check out the free book section on my site, you will find two great books about RF. The transmitter works from 2 V to 12 V and the receiver from 3.3 V to 6 V, I supplied it with 5 V in my circuit.

RF Receiver and Transmitter schematic with ATMega32 ,TLP315, RLP315 operating on 315MHz
Schematic for the RF Project, I made only one schematic instead of two to save space (of course the TLP and RLP RF modules are connected to supply voltage as well even if it is now shown on the schematic)

In the datasheet I read the speed can go up to 2400 baud, however I could get it only working up to 1200 baud. In telecommunications and electronics, baud is a measure of the “signaling rate” which is the number of changes to the transmission media per second in a modulated signal. It is named after Émile Baudot, the inventor of the Baudot code for telegraphy. For example: 250 baud means that 250 signals are transmitted in one second. If each signal carries 4 bits of information then in each second 1000 bits are transmitted. This is abbreviated as 1000 bit/s (this baud part was taken from Wikipedia).
RF Receiver and Transmitter signal on HAMEG Oscilloscope
Analyzing the received and transmitted signal on my HAMEG Oscilloscope

I used two ATMega32 microcontrollers, you can use any other with hardware USART (Universal Synchronous Asynchronous Receiver Transmitter) capabilities however I have few of them laying on my table. I had some problems with GNU C and CodeVision C to receive data over the USART so I found an example code in assembler how to transmit and receive data over the USART.

Here is only the receiver code, the transmitter code is in the zipped project file.

  1. .include “m32def.inc”                      ; Use the ATMega32 library
  2. ; so you don’t have
  3. ; to remember all the addresses
  4. ; of registers
  5.  
  6. .def temp = R16                              ; Call register R16 temp
  7. .equ CLOCK = 4000000                      ; Set the frequency to 4 MHz
  8. .equ BAUD = 1200                          ; Set the baud rate
  9. .equ UBRRVAL = CLOCK/(BAUD*16)-1          ; Calculate the the baud
  10. ; rate for our crystal (4MHz)
  11.  
  12. .org 0×00                                 ; Start at the 0×00 location
  13. rjmp main                         ; Jump to main
  14.  
  15. .org URXCaddr
  16. rjmp int_rxc                      ; If interrupt happens jump
  17. ; to int_rxc
  18.  
  19. ; Main program code
  20. main:
  21. ldi temp, LOW(RAMEND)              ; Define the addresses for
  22. out SPL, temp                     ; the stack
  23. ldi temp, HIGH(RAMEND)
  24. out SPH, temp
  25.  
  26. ldi temp, 0xFF                    ; Put 0xFF into temp
  27. out DDRB, temp                      ; Set PORTB as output
  28.  
  29. ldi temp, LOW(UBRRVAL)              ; Set the baud rate
  30. out UBRRL, temp
  31. ldi temp, HIGH(UBRRVAL)
  32. out UBRRH, temp
  33.  
  34. ; Frame-Format: 8 Bit
  35. ldi temp, (1<<
  36. out UCSRC, temp
  37.  
  38. sbi UCSRB, RXCIE                  ; Interrupt bei Empfang
  39. sbi UCSRB, RXEN                   ; RX (Receiveing) activate
  40.  
  41. sei                               ; Activate intterupts
  42.  
  43. loop:   rjmp loop                         ; Your code should be here
  44.  
  45. ; This interrupt routine will be executed if a byte is received
  46. int_rxc:  ; int_rxc routine starts here
  47. push temp                         ; Save temp on the stack
  48.  
  49. in temp, UDR                      ; Put the received byte into temp
  50. cpi temp, ‘U’                     ; Compare the received byte with ‘U’
  51. brne int_rxc_1                    ; If not equal then go to int_rcx_1
  52. cbi PORTB, 0                      ; else turn off PORTB.0
  53. int_rxc_1: ; int_rxc1 routine starts here
  54. cpi temp, ‘0′                     ; Compare the received byte with ‘0′
  55. brne int_rxc_2                    ; If not equal then go to int_rcx_2
  56. sbi PORTB, 0                      ; else turn on PORTB.0
  57. int_rxc_2:  ; int_rxc2 routine starts here
  58. pop temp                          ; Return old value to temp that
  59. reti                              ; we saved before and return to loop!
  60.  

The code is even easier to understand in assembler than it would be in C. I have created only to toggle the PORTB.0 port HIGH or LOW depending of what was received, you can easily modify the code and make an alarm system or receive some other data, you are the wizard now! Let your imagination lead you to your wishes. The next step in this project is going to be the implementation of Manchester encoding, in that case the speed will be reduced to the half of the current speed but the data transfer will have a reduced BER (Bit Error Ratio). I will dedicate another article just for telecommunications.

RF Receiver and Transmitter created devices
The created devices compared with 2 KM coin (Bosnian currency) and one Euro coin.

Download the complete project with Assembler source code for the Receiver and the Transmitter with pictures.

Entry Filed under: Electronics, DIY, RF

235 Comments Add your own

  • 1. James Conbeer  |  |  March 12th, 2006 at 6:17 pm

    Very nice. I hope to use this in some projects in the future.

  • 2. clifford  |  |  March 12th, 2006 at 7:08 pm

    sweet did all the ground work. thanks alot i am going to use this in my new project

  • 3. Alex  |  |  March 12th, 2006 at 7:54 pm

    Sweet, now I’m looking at this and looking at my old Orange SPV Classic, and looking at it’s infra-red port and thinking…. hmmmmm

  • 4. Tommi Rouvali  |  |  March 12th, 2006 at 9:54 pm

    Any comments on real operation range?

  • 5. david  |  |  March 13th, 2006 at 12:44 am

    hck can it be used to send a audo like speekers

  • 6. Ben  |  |  March 13th, 2006 at 2:57 am

    @david (#5)
    it can if you use A/D and D/A converters, though at 1200 baud you may not get the best sound quality

  • 7. Kevin Yurasits  |  |  March 13th, 2006 at 5:38 am

    Yo i enjoyed the story,and i am looking forword to making it, hope you can help me if i have problems i am still confused by some stuff but i think i might be able to figure it out. thanks kevin

  • 8. SeBsZ  |  |  March 13th, 2006 at 8:24 am

    Hey,

    Can I use ATtiny2313’s to do this? Is there are reason why you need such a big microcontroller, you’re not even using all the pins! Is it for speed? Speed is not too important for me, I can make the ATtiny2313 go at 8Mhz, what speed can I get with that?

    THanks,
    SeBsZ

  • 9. Zach  |  |  March 13th, 2006 at 8:45 am

    Yeah, you should be able to use any microcontroller. As far as I know, it simply takes whatever value you put into the transmitter pin and makes it be the same way on the receiver pin, like magic!

  • 10. hireBASS  |  |  March 13th, 2006 at 9:18 am

    Sup,

    Have you ever seen the Antenna array at Exmouth / North West Cape, Western Australia

    Some people believe is it some type of Tesla type thing. My Poppa worked there for many years, you could walk near it with fluro tubes and they would light up.

    See I’m no electronics genius but you don’t get that type of outcome from a VLF antenna do you?

  • 11. Ivan Minic  |  |  March 13th, 2006 at 10:43 am

    Great tutor champ!

  • 12. SeBsZ  |  |  March 13th, 2006 at 3:36 pm

    I think I have misunderstood this. I didn’t know I had to buy those transmitter receiver things.

    Is there any way to completely build your own receiver and transmitter? I just want one digital signal to be wirelessly transmitted to the receiver. For example, on the transmitter, if one pin goes HIGH, it should immediately go HIGH on the receiver. Same when it goes LOW. Is there a way to do this, and attach antennas etc. to increase range? I probably need only about 50m range.

    I hope someone can help me out here or provide me with some ideas. Email me at sebs89 at gmail d0t com or MSN message me at sebs89 at msn d0t com

    Thanks!

  • 13. refikh  |  |  March 13th, 2006 at 5:39 pm

    Wow, so many comments in one day! Thank you guys. Sorry for my late responds but I am all day at the College. So let’s start answering:
    Tommi: I didn’t test it outside of my flat however it should be about 150 - 200 m outside.
    David: 1200 bauds are to slow for voice, for voice quality I guess you need 64 Kbps and 8000 samples per second. As Ben said.
    Kevin: Of course Kevin I will help you as much as I can and other visitors as well.
    Sebsz: Yes, you can use ATtiny2313

  • 14. refikh  |  |  March 13th, 2006 at 5:46 pm

    Sebsz: You can build your own transmitter and receiver however I dont recommend it if you are a beginner because RF is very sensitive to all kind of noise that’s why I bought this pair! I hope in near future I will make such a transmitter/receiver pair so everybody can build one.

  • 15. refikh  |  |  March 13th, 2006 at 5:50 pm

    HI hireBASS,
    I am not sure, I have never tried it however I believe you wont get that effect. I have never been to Australia, I have some family living there so maybe I will get a chance to visit them.

  • 16. Ravi  |  |  March 13th, 2006 at 9:44 pm

    Cool project. I would like to know how do you get the program onto the microchip, what kind of hardware do you use.

    thanks
    Ravi

  • 17. Bloggitation » link&hellip  |  |  March 14th, 2006 at 1:31 am

    […] How to build your own wireless receiver and transmitter device? Use RF in your next embedded application design! (tags: hardware wifi fun) […]

  • 18. Raj  |  |  March 14th, 2006 at 11:01 am

    Hi,
    Can you also show how the transmitter and receivers are connected? THe schematic? I tried once with a similar module but for some reason didnt work.

    Thanks

  • 19. Jay Turcot  |  |  March 14th, 2006 at 5:49 pm

    I’ve tried building a similar setup with chips from Laipac as well (315 MHz) but I’m only getting accurate transmission over a 1-2 feet in my room. Anything further and my receiver starts timing out waiting for the signal.

    What kind of antennas did you use? Is there any other external circuitry or extral factors I should be considering?

    Engineering design project due in a few days, so I’ve got to get this figured out! Thanks for any help

  • 20. jean routhier  |  |  March 15th, 2006 at 5:37 pm

    Bravo!
    Great tutorial indeed! Really curious about this DIY approach. Can you tell me if it would be possible to use multiple transmitters for one receiver? Would the receiver be able to differentiate between one transmitter or the other?

  • 21. refikh  |  |  March 16th, 2006 at 4:17 pm

    Ravi: You need an AVR programmer (for the AVR series of MCUs but you could implement this project on a PIC as well). The data is transferred and stored on its flash memory (chips memory).

    Raj: I will send you an email, however only ground is connected to ground from the transmitter and receiver, and Vcc to the output of the 7805 voltage regulator.

  • 22. refikh  |  |  March 16th, 2006 at 4:19 pm

    Dear Jay,
    I used only a wire as the antena that has a height of 15 cm! Not sure what it could be, maybe your batteries are bad or the software is not good how it was implemented, what I doubt.

  • 23. refikh  |  |  March 16th, 2006 at 4:21 pm

    Dear Jean ,
    I have never tried it! Not sure, but there must be a way to use a protocol and to implement this with some encodings however I am not sure how to do that.

  • 24. BotHack » Blog Arch&hellip  |  |  March 18th, 2006 at 5:15 am

    […] How to design your Wireless receiver and Transmitter […]

  • 25. Elvis  |  |  March 18th, 2006 at 11:49 pm

    hey could you use this circuit to transmit data to an LCD or keyboard or trackball? how many inputs are on this?

  • 26. Eric Mathison  |  |  March 19th, 2006 at 7:01 am

    Great write-up… are you available to do custom projects for money? If so, please email me…

  • 27. Justin Pierringer  |  |  March 19th, 2006 at 7:10 am

    Hey thanks for the tutorial, I was wondering if you could tell me what other components i am going to need to make these curcuits. I have ordered two 4 MHz crystals, the rf modules, 2 ATMega32 and the dev board along with the needed cables. I know I still need to get some capacitors, 4 of which are 1uF but the others I dont know. Am I missing anything else? I am new to all this hardware stuff although I am good with a soldering iron…

    Thanks in Advance!

    Justin

  • 28. refikh  |  |  March 20th, 2006 at 9:59 pm

    HI Elvis,
    Yes! This circuit can be used for that and I am planning to do something similar as that! It depends what keyboard you use, I mean what kind of protocol it runs on! There is a project on the site how to run a LCD with the ATMega microcontroller.

  • 29. refikh  |  |  March 20th, 2006 at 10:04 pm

    Hey Justin,
    I am glad you consider this useful and you want to try it out yourself, the best way of learning things is by trying them out yourself :) . You will need LM7805 Voltage regulator, 4 capacitors 22 pF, some capacitors for the input and output of LM7805 to stabilize the voltage, 2 10k resistors and reset buttons for the AVR. That should be it, I buy mostly one or two parts more so if something goes wrong I have a reserve :) .

  • 30. Justin Pierringer  |  |  March 20th, 2006 at 10:09 pm

    Thanks for the response, i will keep you posted!

    Justin

  • 31. jim  |  |  March 23rd, 2006 at 5:21 am

    the story about Tesla was good. i like how you actually care. i read a book called “a short history of nearly everything”(its about the history of science) and it was filled with people getting screwed over, when they rightfully deserved something. even still today, certain people are yet to be recognised.

  • 32. Todd  |  |  March 24th, 2006 at 4:14 pm

    Very nice project! I also found the e-books on your site extremely useful.

    Todd

  • 33. Vijay Tingare  |  |  March 27th, 2006 at 11:56 am

    It’s very nice information and project.

  • 34. harsha  |  |  March 28th, 2006 at 4:51 pm

    i woukd like to have some pictures of microcontroller programming devices that are connected to pc for programming the microcontroller.i dont have a basic bit of knowledge about microcontrooers.can you help me with it by sending an emial about it,in form of notes.plz help me

  • 35. refikh  |  |  March 29th, 2006 at 11:07 am

    Thank you for the comments people :) .

    Yeah, mostly the smart guys get screwed up by people that know less than they do… If we just knew where our lives are leading us, everything would be different……

    Dear Harsha, I will try to get in touch with you over the weekend, I have some exams now. Thanks for the understanding

  • 36. Ricki  |  |  April 3rd, 2006 at 1:16 pm

    Hi, Can you change the frecuency in this design?, If I can what I have to do to change the Transmitter frecuency.
    Thanks

  • 37. Darko Fuduric  |  |  April 3rd, 2006 at 2:33 pm

    Great tutorial, I have tried to do the same with Conrad radio modules, with CodeVision, ATMEGA32, and UART(s) connceted to receiver and transmitter modules, and it works but for each character sent I get sometimes two, sometimes three chars, one of them is correct character. I cannot filter wrong chars because of probability impact :-) I would try your assembly code. Thanx !

  • 38. lame_saint  |  |  April 4th, 2006 at 9:00 am

    hi, i just wanna know how can i connect this through pc? i have this project of mine that really needs this device, hope you can help me sooner, because i’m gonna need this badly, this is for my thesis, actually. Thanks a Lot!….

  • 39. refikh  |  |  April 4th, 2006 at 4:53 pm

    Dear Rick,
    Yes, you can change the frequency easily when you build the transmitter and receiver yourself, however in my case I used already made RF modules which work on 315 MHz, I think you can get the same modules on 418 and 433 MHz. I hope this will resolve your problem.

  • 40. refikh  |  |  April 4th, 2006 at 5:04 pm

    Hey Darko,
    next time feel free to ask in Bosnian (Croatian, Serbian or however you call one same language.) OK Darko, what you have to do is to implement some kind of encoding algorithm. I suggest you to use Manchester encoding, you transmit a 01 for 0 and 10 for 1, or it is vice versa (I am not 100% sure.) Another way to resolve your problem would be to send two or three ‘U’ before your message and after it, like UUUUyour_data_hereUU. I have choosen U because its ASCII notation is 01010101 and that should stabilize the RF connection. This should resolve your problem, at least I hope!

  • 41. refikh  |  |  April 4th, 2006 at 5:12 pm

    Dear lame_saint,
    what you could do is use a MAX232 from MaximIC and connect this to your serial RS232 port and use the same approach as I did; and write a little program in C or C++ that will transmit and receive data, I have tried this under Linux and works just fine. I hope this helps, if not let me know!

  • 42. david  |  |  April 13th, 2006 at 4:25 pm

    i dont understand thisyoursite.every thing has completely changd
    please could you guys go back to the old format of last month

  • 43. rajasekhar  |  |  April 14th, 2006 at 8:43 pm

    i wanna know how data is transmitted or received on AIR…. i dont find any link to ur free books for learning it…pl help me out…

  • 44. scOti  |  |  April 16th, 2006 at 7:28 am

    nice :)

    u have a good idea !

  • 45. noa  |  |  April 16th, 2006 at 4:52 pm

    Hey, i have a wireless xbox controller i’m trying to get my router to recognize, how can i adjust the controller to 802g or higher? thanx

  • 46. John Pangle  |  |  April 21st, 2006 at 2:01 am

    Hello,
    I am designing a device that needs to wirelessly activate a solenoid. The transmitter needs to have a 1/4′’ female jack so that I can plug a switch into it. I had planned on using parts from an RC car until I saw this article. Do you think the project you described would work for my application or would it be easier to just use recycled parts from an RC car? Any other suggestions would be greatly appreciated.

    The prodoct I am designing is an automatic drumming machine which will be used by children with disabilities. There is a center where they have drumming sessions and they want the children that cannot physically pick up a drumstick to be able to participate. The children will use existing switches that are attached to their wheel chairs and we will also make one push button swith for the device.

    Thanks,
    John Pangle

  • 47. refikh  |  |  April 21st, 2006 at 8:26 pm

    Sorry guys I didn’t get earlier to you but that is because of the exams!
    David, the site is easier to maintain now and the things are easier accessed. Sorry for the changes however most people like it how it is.

    rajasekhar, go to http://www.e-dsp.com/free-ebooks/

    noa, I am not sure how that could be done, I have never seen an X-box beside TV and Internet so I am not sure…

  • 48. refikh  |  |  April 21st, 2006 at 8:37 pm

    Dear John P.,
    first of all I would like to tell you that you are doing a great thing, helping the children is just great. I donate some money to the SOS Kinderdorf here in Sarajevo as well and I try to help people on the street whenever I can, it makes me feel a bit better in this cruel world.

    I think you could use an RC car controller as well but you could use what I have done and preprogram it to add some aditional functions so they can compose music out of few already made drum beats (this is just an idea). Let me know if I can help you more with this device. Good luck with it John :)

  • 49. kurt.huang  |  |  April 24th, 2006 at 9:45 am

    this is good idea.

  • 50. david  |  |  April 24th, 2006 at 8:57 pm

    Very good tutorial. The story was alittle depressing.

  • 51. Meaoui Alaeddine  |  |  April 30th, 2006 at 9:14 pm

    hi,thx.
    can you help me about the schematics for a rs232 wireless interface.
    THANX

  • 52. martin  |  |  May 1st, 2006 at 7:09 pm

    might be a stupid question, but… how do you load the program into the IC? I can’t find any data in? do you have a have a device programmer to upload it?
    Thanks in advance
    Martin

  • 53. Matt  |  |  May 2nd, 2006 at 7:27 pm

    Thanks for sharing all of this. do you have a parts list that I could get from you? I want to build a few of these. How would I go about getting more distance out of them? I want to put cameras in mine and my friends r/c air planes and get some good footage. Thanks matt

  • 54. Refik  |  |  May 3rd, 2006 at 7:36 pm

    Dear Meaoui,

    Yes I can help you! Just contact me!

  • 55. Refik  |  |  May 3rd, 2006 at 7:40 pm

    Dear Martin,
    Stupid question don’t exist!! Yup, I use the Atmel AVR STK500 programmer. If you need it explained more in details, let me know!

  • 56. Refik  |  |  May 3rd, 2006 at 7:58 pm

    Dear Matt,
    You are welcome :) . Sharing is a good thing when it comes up to knowledge! OK! More distance would mean building an RF amplifier or using another RF module with more power, would be another solution. I am not sure if this is appropriate for transmitting pictures, it is too slow! It would take you a lot of time to transfer the pictures maybe using a specialized transmitter and receiver for that however it can be done. I got these parts from SparkFun. If you want to transfer some other data as the air temperature, acceleration or etc. this would be very useful for you! If you need more details or more help let me know Matt!

  • 57. Master of Destiny  |  |  May 4th, 2006 at 5:16 pm

    Tesla Was one of the greatest inventors ever. Wikipedia did an excellent summary (http://en.wikipedia.org/wiki/Tesla), but there are a few more points you should hit on. Marconi Stole Tesla’s radio, Tesla was the victim of Obsessive Compulsive Disorder, and Thomas Edison effectively sought to destroy Tesla because his views would destroy Edison’s empire ( DC didn’t win the race). The bright spot is that his papers are finally being de-classifeid (unfortunately the bulk is still classified). You have to admire any documents that are still classified after half a century…

    Excellent job on the project.

  • 58. sonal mahurkar  |  |  May 9th, 2006 at 10:05 am

    It Helped me for my project

  • 59. Meaoui Alaeddine  |  |  May 16th, 2006 at 11:50 pm

    So Mr Rafik,
    i sent for you the schematic of my project.
    i’m asking just what is the radio discriminator.????
    Thx

  • 60. Sam  |  |  May 18th, 2006 at 6:28 pm

    Thank you for providing the sample code.
    I am interested to build wireless sensor network with multiple nodes. How can i use this code in my project. I think i need to worry about concurrency and other issues. Any help will be deeply appreciated.

    Thank you

  • 61. Meaoui Alaeddine  |  |  May 19th, 2006 at 5:12 pm

    the link is :
    http://ieee.uow.edu.au/~daniel/projects/radio_link/

  • 62. Meaoui Alaeddine  |  |  May 26th, 2006 at 8:48 pm

    dear rafik!
    i m waiting for your help

  • 63. Pavel  |  |  May 31st, 2006 at 11:36 am

    This site is very useful for project works.

  • 64. meaoui alaeddine  |  |  June 4th, 2006 at 9:29 pm

    did it work ???
    i have some trouble.

  • 65. John  |  |  June 8th, 2006 at 2:23 am

    This is a good project.
    Is there a way to have wireless transmitter-receiver and
    receiver-transmitter at the same time? I want to exchange data via uart between two microcontrollers. I use Atmel atmega8535 chips, i have already made the source code, but i do not know where can i find a trasiever for both microcontrollers.
    If i use your transmitter and receiver twice for my project, i think that they propably have conflicts-noise between them.
    Any ideas?

  • 66. george vasquez  |  |  June 14th, 2006 at 10:15 pm

    how do i get a kit to build a set

  • 67. sebas  |  |  June 27th, 2006 at 12:05 pm

    just an ask :
    - if you get the signal from reading a magnetic stripe card
    you can use this trasmitor to send the digital data and i espect
    from someone that can help me with explanations.
    thanks you much !

  • 68. Matt  |  |  July 6th, 2006 at 7:40 pm

    I am looking to build two small wireless devices. Can you help I am willing to pay you. Contact me at my email.

    Thanks
    matt

  • 69. Tomislav  |  |  July 7th, 2006 at 3:50 pm

    Ludilo, svaka cast!

  • 70. Freak5  |  |  July 8th, 2006 at 12:34 pm

    Nice article but I don’t agree with your story.
    Nicola Tesla didn’t invent the AC, which was invented in Germany http://de.wikipedia.org/wiki/Wechselstrom .
    He just improved it a bit, but it was good enough before.

    And he didn’t invent the radio transmission. The basics were invented by Rudolf Hertz.
    http://de.wikipedia.org/wiki/Heinrich_Rudolf_Hertz
    And the radio telegraphy was invented in Europe by some scientists before WW1, but not by Tesla.
    http://de.wikipedia.org/wiki/Telegraphie

  • 71. leucos  |  |  July 11th, 2006 at 7:41 pm

    mam, how can i built a rs232 wireless device, i try but i don´t care…maybe if i use some a/d and d/a conversor i get more band spectrum!!??..am i right?…please don´t giva fock about my poor english!!!

  • 72. JohnSmith  |  |  July 12th, 2006 at 2:33 pm

    The codes are in assembly. Can you or somebody else translate it or write codes in C? That would be great.

  • 73. Mustafa  |  |  July 20th, 2006 at 10:03 am

    Dear Sirs
    Pelase send me to my email adress wireless picture transmitter with receiver aplications user plan shcematic diagram .Thanks.
    mustafa gürkan
    info@gurkanelektronik.com.tr

  • 74. Ishan Chattopadhyaya  |  |  July 22nd, 2006 at 6:12 am

    Can a PIC16F84A be used somehow to achieve 8-bit transmitter/receiver?

  • 75. refikh  |  |  July 24th, 2006 at 11:14 am

    Dear Ishan,

    Yes, it can be used!

  • 76. renuka  |  |  July 25th, 2006 at 5:42 am

    hello sir,
    please send a mail “how to design a simple wireless transmitter and receiver” (with some pictures).
    thank u sir

  • 77. ellsworth  |  |  July 25th, 2006 at 6:20 am

    i just wanted to say that this info has been a great help thank you but i have a queston could this be used to extend the distance of an rf reader to relay data to my “book”

  • 78. vikrant  |  |  July 25th, 2006 at 10:13 am

    Dear sir,

    i am doing project in wireless transmitter and receiver,can u send me the circuit diagrams,or any links where i can find the circuits

    thanks
    vikrant

  • 79. Dr. Naveed  |  |  July 26th, 2006 at 9:12 pm

    A.A
    i have search your web site i enjoy me. please i requird me data transmitter and receiver 5km range ok bye.

  • 80. Kittisak  |  |  July 27th, 2006 at 7:03 am

    Dear sir,

    i am doing project in wireless transmitter and receiver,can u send me the circuit diagrams , RF_project.zip

    thanks

  • 81. Christopher Ajiduah  |  |  July 27th, 2006 at 12:13 pm

    Thanks very much for your article and the attending device and system descriptions. It is impressive.

    I was telling my wife today the observations I made several times about the lack of credit given to Nikola Tesla in Radio classes and texts. This is a rape on acedemics. Thank you once again for your insight.

    With best regards,

    Christopher

  • 82. Ana Djordjevic  |  |  July 29th, 2006 at 8:36 am

    Are there any good sites which explain how to build your own transmitter/receiver from scratch? For our project we need to transmit at 27MHz…

  • 83. refikh  |  |  July 29th, 2006 at 10:05 am

    Dear Ana,

    Thanks for the comments! Could you explain me your project in more details and then I might be able to help you… What kind of data do you want to transmit, voice, text, images or etc.? Btw. Are your roots from Balkan, if they are feel free to contact me in serbocroatian if it is easier for you.

    Good luck,
    Refa

  • 84. domonic  |  |  July 29th, 2006 at 5:45 pm

    great tutorial…do you think there would be alot of problems trying to implement this on a TI 83 or 84? and would they be able to be overcome with a fair amount of ease?

  • 85. mits  |  |  July 30th, 2006 at 11:24 pm

    Hello, I would like to say congratulations for the effort. Hopefully you gave me a few ideas - if not the WHOLE ONE for something I am preparing. many thanks and keep up!

  • 86. Anirudh  |  |  August 12th, 2006 at 10:34 pm

    HI,
    I’m planning to make a Wifi Card that can be embdded in any appliance like bulb and that device can be operated over Wi FI.. So that a remote user in Wi FI can turn on the bulb with his laptop .. can u provide some help??

  • 87. Anirudh  |  |  August 12th, 2006 at 10:37 pm

    mail me if anybody has any ideas or knows about such stuff…
    ” anirudh.bh@gmail.com”

  • 88. dasari  |  |  August 15th, 2006 at 3:57 pm

    hi

    iam working on wireless metrology in which i have to transmit the dail test indicator data is 4800 buad

    i would like know can i build the circuit on strip board , are there anyspecial boards for it

  • 89. tintin  |  |  August 16th, 2006 at 4:23 pm

    thanks for your contributions. I am doing a transmitter and a receiver for my final year project now, i hope this project can help me but i just found that the price for the Atmel AVR STK500 programmer is too expensive for me. As you mentioned, i can implement it by using PIC16F84A?can you point me more details on it? By the way, does anyone try this out? can you kindly share with me?

    Refa, can you send me the schematic diagram for this project. How can i get more details and idea on how your write the assemly code?thanks.

  • 90. bravish  |  |  August 28th, 2006 at 12:57 pm

    :)

  • 91. bravish  |  |  August 28th, 2006 at 12:58 pm

    nice

  • 92. Matt  |  |  August 28th, 2006 at 4:15 pm

    These (and other) transmitters and receivers are also available at Palm Electronics - and they sell through EBay.

    About the same price.

    -Matt

  • 93. MC  |  |  September 8th, 2006 at 2:39 pm

    Thanks for breaking this down. I have numerous plans for integrating RF. Question: what do you have drawn and labeled as IC2? and are all cap values 1 microfarad? and what is the value of R1? Thanks for the help.

  • 94. vijay kumar  |  |  September 10th, 2006 at 1:57 pm

    sir i am a gr8 fan of urs .can u tell me how to make a very small button size digital camera.i was looking this site for the same but i cudnt get it .so you are requested to send the information in a very detail manner.thank you

  • 95. Sunil M.  |  |  September 12th, 2006 at 2:43 pm

    this was a good one ….

    i want to create a robot which can transfer data like distance from obstacle and more from the robot to the pc.i either want to use rf or ir….can anyone help….if anyone knows how to do these tasks using bluetooth please help………

  • 96. manohar k  |  |  September 16th, 2006 at 7:30 pm

    sir,
    thanks for giving good detailed about the good project.
    i want to do this project in my M.Tech .so, please help me abt the requirements,development.
    pls send mail
    thanks

    by
    manohar k

  • 97. Paola  |  |  September 19th, 2006 at 1:29 pm

    Sr. would you please e-mail me more info. for this project. I want to build this same receiver/transmitter, but I’m afraid I won’t be able to…could you send me more info. on this?? what parts should I buy besides the RLP & TLP 315 and the ATMega32 microcontrollers?? Any more info. would be appreciated it !!!
    thank you so much,
    Paola

  • 98. Paola  |  |  September 20th, 2006 at 3:06 am

    If anyone has more information on how this works please e-mail it to me at: pz1@students.uwf.edu
    I woudl love to get more schematics, and explanation on how to buil it and make it work…also, can anyone give me the list of parts that I need for this project? do I need a dev board and if so, what kind?? please please…I need more info. on this and would really appreciate it…
    thank you so much,
    Paola

  • 99. somesh  |  |  September 26th, 2006 at 1:38 pm

    i will try using your tx and rx for my project, does it work with tx of digital data, i need it coz i will be using multi transmitter but a single reciever, digital data will be easy to distinguish….

  • 100. John  |  |  October 3rd, 2006 at 7:46 pm

    Great Explanation.
    I have only one doubt, in this set only one microcontroller sends the information and the other receives? or the information goes both ways? In one picture i see only a transmitter and a receiver but in the schematics i see the receiver and transmitter both connected to one microcontroler.
    Sorry about the english.
    Thanks in advance

  • 101. EVAGORAS-ELECTRONIC INSTITUS IN GREECE  |  |  October 3rd, 2006 at 10:20 pm

    Mmmmm..!!! nice circuit , well i am thinking to use it as wireless thermometer with ADC0805 . if any one has an opinion on how can i build this circuit it will be my pleasure . sorry for my English.

  • 102. EVAGORAS-ELECTRONIC INSTITUS IN GREECE  |  |  October 3rd, 2006 at 10:42 pm

    the thinking project:

    1) thermistor->ADC(with wake up circuit for saving power)->SERIAL->ARV->transmitter

    2)receiver->AVR->LCD

    Can any one help me for this project i’m very seriusly thinking to build it.thanks

  • 103. Max  |  |  October 3rd, 2006 at 10:52 pm

    Dear Sir,
    firstly i thank you for your amazing project and sharing it with us. i wish you all the best in ur work.
    my question is:
    if i want to increase the reliability of the wireless system used in ur project, i mean implmenting some techniques such as: Cyclic Redundancy Check and FEC and some others, is there away that can be done by programming the microcontroller which is interfaced with the transmitter/ receiver? or do u i have to build an RF transceiver from scratch and then implement if?

    i will be so greatful if you can email me with the answer please.

    all the best.

  • 104. punit  |  |  October 5th, 2006 at 9:16 am

    sir i m working on a project based on “DATA COMMUNICATION BETWEEN TWO ATMEL 89C51″so how i can connect these transciever and reciver to make it wireless.

  • 105. rizzi  |  |  October 8th, 2006 at 1:46 pm

    very nice and helpful. i have a question? where can you find USART? we have an investigatory project in school and we planned to create our own transmitter device from recycled stuff. and am wondering if maybe you can give me some suggestions. thanks

  • 106. Ali Bin Tariq  |  |  October 10th, 2006 at 7:57 am

    Thanx for sharing such a nice project!!!

    Thumbs up for you!!!

    Could u please send me a detailed schematic including the coneection of transmitter and reciver….

    Also please tell me the type of antenna you used in this project, i m totallu confused as far as this antenna is concerned….May i use some home made antenna i-e makin a coil from a wire…..

    Many thanx,

    ALI

  • 107. parul  |  |  October 12th, 2006 at 6:21 am

    hello sir
    i am trying to design RF transmitter & reciever for transmittign digital data ….as my final year project, can u please guide for the design

    thanking you.

  • 108. tushar  |  |  October 13th, 2006 at 12:50 am

    i have to make a transmitter and a reciever work
    can bu tell me anything easier than using a microcontroller
    thanks a lot for the project

  • 109. Paco  |  |  October 13th, 2006 at 5:01 pm

    Easy & cheap… congratulations.

    I’ll try in the near future with radio transceivers, in & out in the same IC but… more expensive obviously.

    anyway i’m thinking in to build this solution for easy control of robotics from the computer with communication i only one way and publish it in my web http://www.xbot.es.

    Paco.

  • 110. dh  |  |  October 14th, 2006 at 8:31 pm

    hey does anyone have any suggestions on how to put these in a graphics calculator? (preferably a ti-84) this would be pretty useful when used with an instant messaging app in school!

  • 111. Ebi  |  |  October 16th, 2006 at 12:42 pm

    hi buddies..

    i jus want to send data between microcontrollers using tx & rx (uart).. but its not receiving anything.. could u help me to overcome the problem.

    i connected the rx pin of 1st mcu to tx pin of 2nd mcu..

    but the problem exixts.. could u all please

  • 112. John  |  |  October 16th, 2006 at 10:01 pm

    I’m sorry for my ignorancy but i’ve made everything that is said here but i don’t know what an IC is and that’s the missing key… Can u please elaborate a bit on that.
    Thanks.

  • 113. John  |  |  October 17th, 2006 at 7:00 pm

    I’m sorry not IC but IC2!

  • 114. rahul  |  |  October 18th, 2006 at 6:33 am

    thanks man i needed it

  • 115. Nek Debaggio  |  |  October 19th, 2006 at 3:38 pm

    Hi all,

    I just ordered all the components mentiioned above and are getting ready to put this together. In the sample code above, in line 43, there is the follwing line “loop: rjmp loop ; Your code should be here” Is this where you type the data you want to send? please help.

    Thanks,
    -nek

  • 116. Avrame Tipikin  |  |  October 20th, 2006 at 12:55 am

    Hi, I am fasinated with transmiters with there recevers, but I just can’t find a place to teach me how to build one from scatch. oh and I am a biggiener so somting esey would be realy great

    Thanks!

  • 117. Avrame Tipikin  |  |  October 21st, 2006 at 12:21 am

    Hi, I am fasinated with transmiters with there recevers, but I just can’t find a place to teach me how to build one from scatch. oh and I am a biggiener so somting esey would be realy great

    Thanks

  • 118. rochelle castolo  |  |  October 21st, 2006 at 11:36 am

    hello sir! we are required to make our own design of an am transmitter receiver in our communication subject using FET but i nt know how to make such design. i hope you coul provide me some of you design..pls……..

  • 119. rochelle castolo  |  |  October 21st, 2006 at 11:37 am

    and your design is really great…… i hope i have brilliant mind like yours.

  • 120. Ajay kumar  |  |  October 27th, 2006 at 7:35 am

    hello sir i am a student of electronic diploma and my father is farmer. he used to go out at night for irriegating the fields of crops and to check that our tube well working ok or not . our fields are 3km far from our house.so i want a transmitter and reciver to switch on/off tube well from 3km distance.
    that circuit should conferm that tubwell is runing ok.i hope you could provide me some of your designe pis……….

  • 121. John  |  |  November 3rd, 2006 at 12:15 am

    Hi there!
    Is there any way, other than RxD, to receive data to the IC. Cuz i need to receive some data, and then send it wirelessly, and also receive wirelessly. so the RxD is already ocuppied.
    Thanks in advance.

  • 122. bilalariseven  |  |  November 3rd, 2006 at 11:01 am

    i tried it and is so beatifull data communication is very good but very short distance for my application i must raise its rf transmittion power

  • 123. snehal  |  |  November 3rd, 2006 at 1:34 pm

    hello sir…
    i am a final year electronics student…..as a part of my curriculum i am suppose to make a wireless transmitter and receiver for transmitting and receiving video images….. please can u guide about this idea…..i really need your help…..
    thank you…

  • 124. heguli  |  |  November 11th, 2006 at 1:10 am

    Just to say: I love you man :) This is a great site…

  • 125. JohnD  |  |  November 15th, 2006 at 5:59 pm

    Dear sir,
    I have everything that u mentioned above, but i have one problem, i don’t know assembly, but i do know C. I was trying to create a C program for this, working with ATtiny2313, but I can’t do it because i don’t know the Microcontroller, i was studying the registers and timer modes etc, and i can’t understand a thing. Can u point me in the right direction please.

    Thanks in advance

  • 126. Nek Debaggio  |  |  November 15th, 2006 at 9:35 pm

    Dear bilalariseven,

    Sounds like you got the project working. Good for you! I am trying to get it working but I get stuck in the following line;

    “loop: rjmp loop ; Your code should be here”

    Any ideas?

    Thanks,
    -nek

  • 127. mr yat  |  |  November 16th, 2006 at 3:36 am

    ermm..can give me a cicurit diagran for auto RF Transmitter and Receiver?actually….i want to use this circuit for my final year project.TQ.

  • 128. jason  |  |  November 19th, 2006 at 12:15 am

    I want to make a mobile wireless motion detector system, I need four detectors and one base unit to signal when the detectors are tripped, Is this possible? Thanks Jason

  • 129. vishwas.k  |  |  November 22nd, 2006 at 6:30 am

    this page was really fascinating sir.i came to know about so many things from this page n iam really inspired to try it out.n iam a final year student,doin engi in sit,tumkur.iam doing a proj on automatic water level controller,for which i want to use wireless transmission b/n tank n motor.so i searched this page through google.actually its very difficult to get what v really want from net,but ur material really helped me a lot. if u have more information regarding my above proj,plz forward it to my above e-mail..thank u sir..

  • 130. ahmed  |  |  November 22nd, 2006 at 7:37 am

    your assabler program is not correct does this project send video at a short distance on a another pc.plz send me c program in c for sender and receiver

  • 131. dhanasekar  |  |  November 22nd, 2006 at 11:15 am

    can u tell me , whether it can be done in VLSI using I^2C model .

  • 132. K.STONE  |  |  November 25th, 2006 at 1:30 pm

    THIS KIND OF ROGUE TECHNOLOGY INTERFERES WITH RKE DOESN’T IT? SO IF THERE ARE PEOPLE TRYING TO SET THEIR CAR ALARMS WITHIN RANGE OF THIS WHILE YOUR DEVICE IS IN OPERATION, IT COULD BE USED TO JAME THEIR SIGNALS NO? MAYBE UNINTENTIONALLY BUT STILL JAM THEM NONETHELESS. I BELIEVE THE FCC HAS RKE’S OPERATING AT 315MHZ-452MHZ.

    JUST WONDERING IF THERE IS ANY CORRELATION BETWEEN THIS KIND OF TECHNOLOGY AND SEVERAL INCIDENCES WHEREIN REMOTE KEYLESS ENTRIES WERE UNOPERATIONAL IN A WIDE SPREAD AREA FOR A CERTAIN PERIOD OF TIME. I.E., LAS VEGAS 2004 AND ALSO IN WASHINGTON DC.

  • 133. Jose De la Cruz  |  |  November 25th, 2006 at 7:51 pm

    Actually, sending a mass of data can be done, depending on the signalling protocol (e.g. HDB3 or other). No 64kbps is required.
    I’ll first explain for voice and then for images:
    The principle is as follows: normally filter voice at 3.4 KHz, sampling is done at 7KHz. Second, either use a compander/vocoder or imagine how to code using signal changes and not amplitude value (like morse: the most frequent, the shortest code), and use a decreasing law (alfa or mu). Look for G726 in Internet.
    For the second is even simpler: first send all the image, and afterwards only the changes (you do the XOR on the transmitting side) either as relative or as absolute coordinates.
    Of course, if signals/images change too quickly, you’ll see it !! but it’s better than the raw approach.
    This I used in Colombia 8 years ago and it worked very nicely, however I do not remember all the details. I can work it out if someone needs it.

  • 134. Jose De la Cruz  |  |  November 25th, 2006 at 8:06 pm

    Dear Somesh ,
    Dear Max,

    Programming a protocol is the best way for both of you (and many others in this forum). The protocol has to integrate the identity for each transmitter, in order to allow the receiver to differentiate.
    The worst problem for Somesh is the collision of two or more Tx that are done simultaneously. This is by no means easy to deal with. Please look for CDMA and Aloha, in order to see how they solved this problem.
    In order to implement the CRC or the FEC, you can use a windowed schema(more efficient in most of cases) or ARQ (this adds too much overhead for short data).This requires a buffer in SW and a very small state machine that feeds it and determines when to ask for a retransmission. Since the baud rate is so low, I suggest you strongly to use CRC, which requires a checksum from time to time. FEC requires adding bits all the time, which means that the bit rate is decreased.

    All depends on how immediate (real-time) is the data, and whether there are bursts or not.

  • 135. Jose De la Cruz  |  |  November 25th, 2006 at 11:12 pm

    Nice site Refikh, Thx!!!

    Concerning the problems about short range, very often it is actually noise that enters into the system. The sensitivity of the Tx & Rx chosen by refikh are very good.

    So, I suggest to people that have found this problem to check the soldering points (no loose components & all thru-holes completely filled up with soldering).
    Next, design an antenna for the 315-440 MHz. Many sites can be googled quickly.
    And get an oscilloscope and verify that the clock, data signal and carrier signals are clean.
    When everything goes OK, the system should work.

  • 136. adegbulugbe adeleke  |  |  November 27th, 2006 at 5:42 pm

    please any one who can help me i need assistance am doing my final year project on wireless pc text messaging thru the serial port,i need to construct a transmitter from the serial port to transmit the text signals as rf and a corresponding receiver which is linnked to a microcontroller and den an lcd for the display

  • 137. sushil kumar jain  |  |  December 6th, 2006 at 1:12 pm

    i want to know how to increase the range of rf antenna. persently its range is 30 mtr. we want increase it upto 100 mtr. i want to make changes only in receiver.

  • 138. asad  |  |  December 6th, 2006 at 9:22 pm

    i need to know how to built 24dbi wireless antena in 2.4 frequency ?

  • 139. nyoms  |  |  December 7th, 2006 at 5:12 am

    i am interest on this article, but i can not download the RF_Project.zip. is other mirror site available ??
    please help me.

    thanks

  • 140. nyoms  |  |  December 7th, 2006 at 5:30 am

    Dear Sir,

    I am interest on this article, but i can not download the RF_Project.zip. Is other mirror site available ??
    Or would you please e-mail this RF_Project.zip file to me.
    Please help me.

    Thanks for your attention.

    Regards,
    nyoms

  • 141. terence  |  |  December 7th, 2006 at 7:22 am

    good d sir,
    can you please help or just a sort of idea on what propose in tthesis? im thinking of using rf as one part of my project. but i still have no idea of what would be my intire design..

    thanks,

  • 142. Avrame Tipikin  |  |  December 14th, 2006 at 4:33 am

    I really want to know how to make a transmitter and reciver that will work with eachother to send anything.
    I’m just so fasenated with it and I really want to learn how to bulid them.

    Thanls alot
    I really want to learn about them

  • 143. matt  |  |  December 16th, 2006 at 7:09 pm

    I don’t know much about electronics. Are they both a transmitter/ resceiver, or is one a transmitter and the other a resceiver? Also, can install this into a video game conrtoller to make it wireless?

  • 144. SEAN  |  |  December 21st, 2006 at 7:58 pm

    hi all,

    is there an easier way to show a beginner how to create just a simple simple transmitter and reciever?

    Like press a button on the reiver and a motor runs on the reciever. PLEASE HELP. I’m so new to this.

    Or talk to the transmitter and hear it on the reciver?

    thanks

    bsxiong@hotmail.com

  • 145. stuart  |  |  January 1st, 2007 at 4:09 am

    hey peeps

    right heres the situation…
    i have just bought myself a fujitsu siemens amilo laptop and have it set up. i have been searching for wifi connections in my area and have found a few unsecure ones just about out of my reach(in other words they only appear really weak if atall!!). i was wondering how i could use something like this to make an antenna to better the signals i recieve because im a bit of a tight arse and dont really want to pay for another connection!!
    any help would be extremely appreciated!

    thanks in advance

    stuart!

  • 146. Opal  |  |  January 1st, 2007 at 3:38 pm

    How about if i want to build a radio-control airplane and fix this inside?

  • 147. JohnD  |  |  January 16th, 2007 at 7:09 pm

    Dear sir,
    I would like your help. I have a problem. I’ve done everything you said, but i’ve used an attiny2313. I’ve programmed the IC with C. A simple program like:
    ” #include “io.h”
    int main(void)
    {
    while (1)
    {
    PINB=4;
    }
    }”
    Just to put pinb2 HIGH, and that is connected to the transmitter’s “Data in” Pin. On the receiver i have also everything set up and “Data out” Pin is not HIGH!
    Why Not?!
    Thank You in advance.

  • 148. JohnD  |  |  January 18th, 2007 at 12:00 am

    Thank you anyway but i have solved that problem by myself, it was necessary to enable uart.

  • 149. S Hari Krishnan  |  |  January 19th, 2007 at 12:16 pm

    Hello Sir,
    its very nice…i doing my project as “wireless controlling system” -for that i need the detail about the TWS434 & RWS434(rf module from reynolds electronics)…..also what type of antenna should be better….

  • 150. Kasper  |  |  January 19th, 2007 at 7:17 pm

    hej u think u can make one of those for a rc car?

  • 151. Kasper  |  |  January 19th, 2007 at 7:45 pm

    do you know how to make a rc speed regulator??

  • 152. juan  |  |  January 19th, 2007 at 8:12 pm

    does any one knows what processor would be grat for a hp pavilion its current procesor is 1.3 ghz

  • 153. rajkumar  |  |  January 22nd, 2007 at 2:36 pm

    sir ,
    i m doin project on wireless reciever transmitter ..
    can u plzzz send me circuit of 1 channel tran. and reciev.
    thanking u ,i remain

  • 154. anuj  |  |  January 26th, 2007 at 6:44 am

    great information, plz tell me how can i buy these transmitter and receiver
    anuj

  • 155. Jinu c george  |  |  January 29th, 2007 at 7:40 am

    sir,
    i am doing a project on rf based automation using 8051 micro controller.can i use tlpTLP&RLP315 to interconnect with 8051.if u dont mind can u send me a shematic for my project.if anyone has idea about this pls mail me.
    jinucgeorge@gmail.com.

  • 156. Remo  |  |  February 1st, 2007 at 7:18 am

    i want a 0.5 to 1 cm long wireless transmitter and riciever for audio communication

  • 157. S.HariKrishnan  |  |  February 1st, 2007 at 10:53 am

    its nice….i am doing my project as “wireless controlling system”
    using rf transmitters and receivers(TWS-434 &RWS-434)…if anybody know how to use , please mail me…..

    krish806_deep@yahoo.co.in

    please…please….please….

  • 158. KELVIN  |  |  February 2nd, 2007 at 5:48 pm

    HEY AM KELVIN I LOVE THIS STUFF BUT I DONT UNDERSND IT BEETTER IF YOU CAN CLEAR ME I WILL BE BEETTRE
    WERE WILL U GET THT MICRO CHEAP

  • 159. KELVIN  |  |  February 2nd, 2007 at 5:50 pm

    I MEAN WERE I CAN GET IT FROM

  • 160. finny  |  |  February 7th, 2007 at 12:02 pm

    Dear electronic friend,

    Iam from india. i am a electronics as well as a music student.
    I would like to build a wireless guitar for myself. can you plz assist me in this.

    I would like t have the circuit diagram for the same.

    Your electronic Friend,

    Finn

  • 161. chintan raja  |  |  February 10th, 2007 at 9:25 am

    Hi i liked ur ckt . i want 2 transmit 8 parameters using microcontroller . which transmission should i use whether it shud b asynchronous or syncronous

  • 162. USMAN KK  |  |  February 14th, 2007 at 4:02 am

    it is right but it no detailed wise thing .tell us steps wise .

  • 163. raathai  |  |  February 14th, 2007 at 10:36 am

    In wireless what type of signaling is used whether digitl or analog.
    what to do to increase the coverage area in wireless

  • 164. Ayush  |  |  February 14th, 2007 at 12:06 pm

    Can u send me some detailed circuits of transmitter and reciever to controll the motors

  • 165. wroberts  |  |  February 16th, 2007 at 6:58 pm

    Hey, I have a small radio transmitter receiver system that I use for photography used to trigger my flash. It missfires often and the range isn’t but about 10 to 15 ft. I want to decrease the missfiring and increase the range. Is there anyway that I can solve these problems relativley cheaply. Thanks guys

  • 166. hoop  |  |  February 23rd, 2007 at 12:47 pm

    hi;
    actuly it seem it issimeler to my project pleae if you can send me all the information that can help us in building like this transmiter and reciver and how we can control the range and if we can make it low power transmiter that work all the time

    thank you , please don`t ignore my request
    my mail is devilkin999@hotmail.com, please

  • 167. hoop  |  |  February 25th, 2007 at 6:21 pm

    please can you send me the concept of how the transmiter and reciver works?

  • 168. Hasan Rashid  |  |  February 27th, 2007 at 4:42 am

    Hi,

    Your article is very informative. I have a favor to ask, I am building a Digital Wireless Microphone, in simplicity it is a reverse of a wireless Headphone. I am having problems with finding a Tx that support the data rate I want. Unfortunately, my professors aren’t being of much help and I am having a hard time. Basically this is my concept

    Transmitter Circuit :
    Mic->Pre-Amp->A/D->(8 bit parallel input encoder)-> Serial input TX

    OR

    Mic->Pre-Amp->A/D->8 bit parallel input TX

    The reciever is the opposite of that. Can you please guide me here. Thanks!

    Regards, HR

  • 169. Jack  |