sre / cff3000-pcb

CFF3000 GPIO Interface

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CFF3000 GPIO interface

This repository contains information how to interface a Abus CFF3000 remote control with a Raspberry Pi or similar development board using GPIOs. First of all one needs to disassemble the remote control. Be careful when removing the rubber part from the PCB to avoid tearing off the antenna.

Disassembled CFF3000

Next step: Soldering a couple of wires. I tried to tap the signals at locations, that are as simple to solder as possible. Unfortunately tapping the LEDs is a bit tricky. Note, that the CFF3000 design is "interesting" and does not use a common ground/vcc for the buttons and LEDs.

Wire locations

To work around the problem with uncommon ground/vcc, I made a small single layer PCB. Some explanations for the schematics: The CFF3000 is connected on the right side of the schematics. Each buttons is connected to a opto-coupler, the other side of the opto-coupler is connected to the computer's GPIO through a resistor as current limiter. The LEDs are also connected to a opto-coupler, but the signal is additionally inverted and cleaned by a schmitt-trigger. This was necessary for proper reading of the green LED. Also the green LED channel has a 100Hz RC lowpass filter (47nF, 33K), since it is driven with a 1KHz PWM signal by the CFF3000 and we want a logical 1 or 0 instead.

Schematic PCB

License

© 2018 Sebastian Reichel

ISC License

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.