ZMK Hall Effect feature module

This module is a collection of drivers, behaviors and input-processors to support Hall-effect switches and features commonly found on HE keyboards

Features

• Adjustable actuation
• Rapid Trigger
• SOCD
• Dynamic keystroke
• Mouse input
• Gamepad input

Drivers

• he,kscan-direct-pulsed: Each HE sensor is wired directly to an adc channel, supports the use of an enable pin to power the sensor only when it needs to be read.
  Generates input events with type INPUT_EV_HE but can also generate kscan events with he,kscan-forwarder(this allows the input processors to use the normal keymap)

This was designed to work with my custom HE keyboard, if you need another driver(e.g. using analog multiplexers), you can open an issue (note that i have no way to test other drivers at the moment)

• zmk,battery-nrf-vddh-channel: Has the same functionality as zmk,battery-nrf-vddh but you can select which adc channel gets used

Note

There is a problem with many nrf52840 chips where if you switch between single channel and multi-channel mode, the adc subsystem stops working, this is caused by anomaly 212 on chips with build codes CKAA-Dx0 or QIAA-Dx0.

Currently if you have an affected chip and enable both drivers using non-overlapping channels (which is necessary to enable both), everything stops working.

Input Processors

These are the analog equivalent of behaviors

• he,raw-signal-processor: Apply a SOS filter to the input signal, this is used to reduce the noise of the sensor
• he,input-processor-matrix-offset: Add an offset in position to the received inputs (the value of the input remains the same, only moves the matrix position)
• he,input-processor-keymap: The analog equivalent of zmk,keymap, passes a received value to the processor for the corresponding key, uses input-processors instead of behaviors
• he,input-processor-adjustable-actuation: Press a key(triggers the behavior in zmk,keymap) or some explicit behaviors when the switch passes a certain height, supports multiple actuation points and unidirectional triggers
• he,input-processor-rapid-trigger: Rapid Trigger(press or release a key when the switch changes direction), only supports continuous mode
• he,input-processor-socd: SOCD (Simultaneous Opposing Cardinal Directions), supports 4 priority modes: last key, first key, deeper key or direction(a combination of last key and rapid trigger)
• he,input-processor-blank-he: The analog equivalent of &trans and &none behaviors, can log when it receives a value
• he,input-processor-gamepad-forwarder: Send a joystick or analog trigger event proportional to the switch height, emulating a gamepad
• he,input-processor-mouse-forwarder: Send X,Y, vertical or horizontal wheel event proportional to the switch height

Behaviors

• he,behavior-gamepad-btn: Send a gamepad button event
• he,behavior-pulse-set: Set the pulse mode of he,kscan-direct-pulsed (turn off the enable pin after the read is done / keep the enable pin always on)

Other

• he,input-listener: Same as zmk,input-listener but it executes the input-processors of the parent before going to the ones in the layers and stops when receiving any ZMK_INPUT_PROC_STOP
• he,input-split: Same as zmk,input-split but doesn't send the input when it receives a ZMK_INPUT_PROC_STOP (only for the peripheral side)
• he,kscan-forwarder: Allows for external control of he,kscan-direct-pulsed(generate kscan events outside of the driver)
• he,pulse-set-forwarder: Allows for external control of he,kscan-direct-pulsed(control how the kscan-direct-pulsed driver works)