Encoders on MCP23017


Can we still use different kind of displays?
Having the waveshare32 and it’s special wiring in mind.


Of course! The main reason to move the controllers to a GPIO expander is easing the configuration of hardware devices like displays and soundcards by avoiding “pin collisions”.

The new All-In-One circuit only uses I2C and the GPIO 25 & 27 (pin 35 & 36) for interrupts. This 2 GPIO ports are rarely used by any device. If you know some device using it, or you think there is a better choice, speak now, please!!!, before i order a few hundred of PCBs! :wink:



So that’s 2 Pins for 12C and GPIO 25 & 27 plus +V ( 3.3V or 5V? or both ) and ground(s)

Anyone any idea how far that could be run before you need to start buffering it . . . ?

I’d like to break out the encoders into a separate enclosure. . .

Well just cos really.


HI @wyleu!

I think it should be perfectly possible to have a few meters. it depends of I2C frequency and cable capacitance. If needed, you can change the I2C frequency tweaking the config.txt, like that:


Just try and give feedback :wink:



I used i2c connection up to 2 meters, and never had problems.
But, as @jofemodo said, you can lower data rate if you have errors.


That sounds about right for what I’m invisaging…

Have we any idea when the new encoder board will be available and what the price might be?


all in one pcb use H11L1 optocoupler IC can use 6n138 its same


I have build all Indonesian one module but no work help me please



Bu of no connect to all on one module with 7 icnh waveshare lcd itu work fine

  1. Visual Inspection & Plug Socket orientation check :smiley:
  2. Your All-in-One board stops a working machine?
  3. Does you pi die (no leds) when you connect All-In-One board?
    If so you have a Power Supply short on All-in-One.
  4. Can you measure voltages? Check (using schematic …) Check PSU pins on All-In_One board.


its work fine but add all in one module with rotarry switct encoder single controller

Success Cases

Continuing the discussion from Encoders on MCP23017:



What is exactly your layout configuration? If you disconnect the All-In-One circuit and configure “Dummy” wiring layout … does it work OK?

Have you tried to test your encoders from the command line?


You also can check if the MCP23017 is “on-line” for the RBPi. Just run this command:

gpio i2c

The default address of the MCP23017 GPIO expander is 0x20 :wink:



1.How do I connect wiring a rotary encoder to switch intelligently all in one module pcb
2.whether to add a capacitor on the back of this such as the pcb looks in this picture?all%20in%20one



this standard all in one module from gifthub zynthian hw


Take a look to this post :wink:


If you can make these encoders work on zynthian, please give me the recipe hahaha! I have not been able to make them work. I’m using the same model on the official all-in-one board.


do any of the encoders produce a response?


A post was merged into an existing topic: Tedy’s Thread


my ky encoder mod https://www.youtube.com/watch?v=2fcvQAucEeE