12 Channel RF Remote Notes

There was some discussion on the builders message board recently about reprogramming the unique encoding on the newer 12 channel RF remotes.

Much of the documentation and notes on various R2 sites are for the older remotes. I thought it might be a good idea to document my findings on the new remotes.

I don’t want to repeat in detail why or how R2 builders use these boards, but the most common is to trigger sounds in your droid when combined with a CF3 sound system. Most of what’s been written about integrating the board into your droid applies no matter which revision you have – but changing the encoding has.

First up, most people find these boards on ebay. Just search on “12 rf remote” and you’ll find a lot of sellers offering them from all over the world. Don’t pay more than $30-40 with shipping. There’s still a few sellers offering the older boards too.

So what’s the difference between them? Not a lot to be honest. The newer boards are easier to reprogram the unique identifying code, and the transmitter is a little smaller. However the new receiver board does have an annoying buzzer that needs disabling.

For the geek in you – On the receiver board, auto learning decoding scheme has been programmed into the MCU IC chip, and inside the remote control or transmitter there’s an Encoding IC Chip, an SC-2262. This set of IC chips can be used to encode your signals so that multiple remotes in close proximity will not interfere with each other. In theory you can pick from 6561 different combinations.

Do you need to worry about changing the code? That’s easy, most boards are shipped with the same factory default code, and you don’t want your droid to clash with some else’s.

For reference, here’s the older board and the remote which is somewhat larger

If you have one of these then jump over to Alex’s original RF remote tutorial.

Warning: The Positive/Negative terminals are swapped on the new and old boards. Please double check everything you’re doing with the latest wiring diagrams from the manufacturer. Don’t assume this tutorial is up to date.

And, here’s the new RF remote/receiver – notice the circle/tab toward the back of the board. That’s the buzzer. If yours has one of these then you have the newer board.

Unlike the older board, to change the unique encoding all you have to do is set it on the remote transmitter and then set the receiver to auto-learn mode, with a press of a button and you’re done. Well that’s the overly simplified explanation.

Here’s an overview of the receiver board with the location of the learn button marked at the bottom left.

Procedure to Learn and Erase Codes

  • Press the “Learn” button on the receiver board, the siren will beep indicating the receiver is ready and waiting to learn from transmitter.
  • Press any designated keys to teach and select Output modes. (See list below)
  • If you need to reset/erase the the receiver due to lost or new remote, press “Learn” button for ~10sec until the siren beeps 3 times, which indicates previous learned codes have been erased.

Output Mode selection

Press 3 for Momentary Mode
Press 6 for Latched Mode
Press 9 for Toggle Mode
Press 12 for Ch1-Ch6: Toggle Mode, Ch7-Ch12: Momentary Mode

To set the encoding, first open up the transmitter

The chip at the bottom labeled SC-2262 is what does all the work.

Remove one more screw and separate the green circuit board from the casing

Notice the 3 rows of 8 little solder tabs at the bottom. That’s where you set the unique code using a soldering iron (one of 6561 or 3×8 combinations.)

Pin 1 through 8 bring out the Encode function of your remote transmitter. The receiver board will automatically learn from the transmitter by pressing the learn button.

On the older boards they used to labels the back of the board with a “H” for High, “L” for Low and numbers of the pin outs. Unfortunately the newer boards don’t have this luxury. I’ve marked up a photo to show the pin outs.

Low or ” L” – Low digital state (Close to GND level).
High or ” H” – High digital state (9-12V).

You should also be able to figure out the “L” and “H” states yourself. After you connect the system to power, use a Voltmeter to measure the contacts on both sides of the column of eight pins (1-8). Voltage level on each side should be consistence. If one side is “H”, the other side should be “L”. “H” level voltage can be measured only when signal is transmitting/receiving. Or simply use the above photo as reference.

Also, you don’t have to connect all eight pins to High or Low, just one will do. In my case pins 3 and 4 are connected to Low, and 7 to High.

Often remotes are default encoded to be 00000001, i.e. pin 8 is shorted to GND.

Encoded IC has following representation:

If the pin is not shorted to anything, its code value is “0”.
If the pin is shorted to Low, its code value is “1”,
If the pin is shorted to High, its code value is a “2”.

A couple of useful sites

  • Light Object – they sell on ebay under the name of coldfusionx, are based in the USA and a lot of R2 builders buy their boards from them. This link has a bunch of support documentation on it.
  • R2-R9.com – Jerry Green’s write up on integrating the remote with a CF2 sound system.
  • AlexKung1.com – Alex’s original RF remote write-up.

Warning: I’ve just been informed that the Positive/Negative terminals are swapped on the new and old boards. Please double check everything you’re doing with the latest wiring diagrams from the manufacturer. Don’t assume this tutorial is up to date.

Posted by Chris on November 30th, 2007 in Electronics | 25 Comments

Tags: , , ,

25 Responses

  1. Calvin Thomas remarks on

    Man Awesome!!!
    Thanks for doing this tutorial.
    I have been putting this off for 2 reasons.
    1- I’m not really ready for this part.
    2- I wasn’t sure how do set it up anyway.
    I may need your help in the future on this.

  2. Chris remarks on

    No problem. I hope it helps people out.


  3. Calvin Thomas remarks on

    On the 12 channel.
    Do all the channels have to be on the same mode or can it be mixed?

  4. Chris remarks on

    Not sure I understand the question. The new RF’s have the modes, Momentary, Latched Mode or Toggle. I think the old remotes only had Momentary and Latch. Best check the documentation.

  5. Calvin Thomas remarks on

    I was wondering if each of the 12 ch’s could have the mode set.
    But it looks like it is:
    All Chs.= toggled or momentary
    1-6 Toggled: 7-12 Momentary.
    It would have been nice to controll each Ch.

  6. Chris remarks on

    yes, correct. You can only change in blocks of switches.

  7. Kalle remarks on

    Have you noticed a situation, that only outputs 1,2,4 and 8 work? My unit works like this. When debugging the unit, there is some action in pins of receiver CPU, when any remote control buttons are pressed. Thus it seems that the remote would transmit, but for some reason, the receiver can’t understand it.

    Any help appreciated… I will offer a beer to person giving me the solution 🙂 Beer will be served in Turku, Finland.

  8. Chris remarks on

    I have not experienced this problem. Sorry I can’t help.

    Have you tried doing a full hard reset of the receiver and rebinding the transmitter?

  9. Nathan remarks on

    When does the siren actually work, when it is on momentary mode does it scream every time you make a selection???

  10. Chris remarks on

    it will tweet ever time you press a button, but you really should disable it.

  11. dheeraj remarks on

    my 12 channel rf remote is not workng due to effrct of high voltage my remote is damaged ….. means some of the component is not workng wts da solution for dat….?

  12. Chris remarks on

    Buy a new remote.

  13. DORU SANDU remarks on

    Dear Sir,
    I’m in trouble, I have two RF remotes made ​​in China, one with PT2264 and the second with SC2222 and two receivers with 12 channels without microcontrollers. I bought 2 x PIC16F57. No software found on the internet in. ASM or format. HEX. Receivers are 12 relays, memory 93C46, ULN2003 drivers, PIC16F57. LED on pin 7. Button pin 8. Sound on pin 10. Can you help me directly or indicating a link?
    Thank you,
    D. Sandu

  14. Chris remarks on

    Sorry, I have no idea where to get the firmware from.

  15. Madhur remarks on

    If 2 set of same frequency work independently at same place.
    If yes please explain how

  16. Chris remarks on

    you can set a unique code on each device.

  17. Madhur remarks on

    How? please explain in detailed procedure

  18. Chris remarks on

    i did in this blog post, didnt you read it?

  19. Madhur remarks on

    yeah thanks dear

  20. Madhur remarks on


    For 12V DC input supply what will be the current rating?

  21. Chris remarks on

    sorry, i have no clue on how many amps are required.

  22. Brian remarks on

    Firstly thank you for your blog which was very helpful

    You say “In my case pins 3 and 4 are connected to Low, and 7 to High” but looking at the picture isn’t it just 4 and 7? I see the low pads for 3 and 4 are soldered together but aren’t all the low and highs connected anyway?

  23. Chris remarks on

    i’d have to double check. the point is each remote has a unique code set with these pins. doesnt really matter what you choose.

  24. Snarkticon remarks on

    Man … RIGHT out of the box mine doesn’t seem to be working … The light on the remote flashes when I push a button, and the buzzer beeps when I press the learn button on the receiver. BUT … nothing happens on the receiver when I press buttons on the remote. It’s like they’re simply not communicating.

    Is there something I’m suppose to do to pair these things together or what? I can’t seem to find any clear instructions anywhere online for these things.

  25. Chris remarks on

    have you tried the pairing tips i gave?

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