Feature Request: Support BS814A Touch Controller

[snookyly]

PROBLEM DESCRIPTION

A clear and concise description of what the problem is.
When trying to figure the setup of Teekar 3-gang wall switch I faced the issue that the touch switches utilizing the BS814A touch chip is not supported by tasmota.

REQUESTED INFORMATION

Make sure your have performed every step and checked the applicable boxes before submitting your issue. Thank you!

• Read the Contributing Guide and Policy and the Code of Conduct
• Searched the problem in issues
• Searched the problem in discussions
• Searched the problem in the docs
• Searched the problem in the chat
• Device used (e.g., Sonoff Basic): Teekar 3-gang wall switch
• Tasmota binary firmware version number used: 9.1.0.2
  • Pre-compiled
  • Self-compiled
• Flashing tools used: Tuya-convert
• Provide the output of command: Backlog Template; Module; GPIO 255:

  Configuration output here:

N/A

• If using rules, provide the output of this command: Backlog Rule1; Rule2; Rule3:

  Rules output here:

N/A

• Provide the output of this command: Status 0:

  STATUS 0 output here:

N/A

• Set weblog to 4 and then, when you experience your issue, provide the output of the Console log:

  Console output here:

N/A

TO REPRODUCE

Steps to reproduce the behavior:
Flash the switch with Tasmota

EXPECTED BEHAVIOUR

A clear and concise description of what you expected to happen.

The three touch buttons should be detectable as switch inputs to Tasmota

SCREENSHOTS

If applicable, add screenshots to help explain your problem.

As shown in the related manual (https://www.holtek.com/documents/10179/116711/BS81xA-xv160.pdf) here is the data transfer timing and the serial data stream format:

ADDITIONAL CONTEXT

Add any other context about the problem here.

Though being a software developer I am unfortunately not able to code the driver on my own due to limited skills in hardware development. Your help is highly appreciated. This request is related to #10185.

(Please, remember to close the issue when the problem has been addressed)

[vic42]

This is possibly going to be my new year's project. Waiting for the hardware to come in.

[vic42]

#ifdef USE_BS814A2
/*********************************************************************************************\
  THE PLAN [tm]:                      OUTCOME:
  ==============                      ========
  appear in a dropdown              
  select 2 pins (clk, data)                        
  poll data pin for low state
  generate high-speed clock (25kHz)
  poll data bits on clock plateau
  update data & report every 50 ms
  error & retry logic (if reqired)
  MQTT message & rules hook

[vic42]

Current driver clock timing:

#ifdef USE_BS814A2
/*********************************************************************************************\
  THE PLAN [tm]:                        OUTCOME:
  ==============                        ========
  appear in a dropdown                  (BS814 CLK, BS814 DAT)
  select 2 pins (clk, data)             DONE
  poll data pin for low state           DONE
  generate high-speed clock (25kHz)     DONE
  poll data bits on clock plateau       sample after rising clk edge
  update data & report every 50 ms      DONE
  error & retry logic (if reqired)      TODO
  MQTT message & rules hook             DONE
  Test on actual Hardware               TODO

  THE PROTOCOL [tm]:
  ==================
  see Holtek-Semicon BS814A-2 datasheet for details
\*********************************************************************************************/

[vic42]

First functional driver version

[snookyly]

Successfully tested. Thanks for implementing.
Can be closed.