Relative rotary encoder subsystem

There is no circuit involved here, just software and wiring.

Purpose

The purpose of this subsystem is to provide one or more relative rotary encoders as inputs to the system. Since a funky switch is a kind of rotary encoder, this subsystem also applies to them. However, only rotation is part of this subsystem. Any built in push button is not part of this subsystem, refer to the Switches subsystem for that.

Wiring

Each rotary encoder requires two dedicated pins at the DevKit board, no matter if they are bare bone or KY-040 rotary encoders. Not counting any built in push button, this is the wiring of a rotary encoder:

• KY-040 type:

  • Pin labeled Vcc must be wired to 3V3 pin at the board.
  • Pin labeled GND must be wired to GND pin at the board.
  • Pin labeled CLK or A must be wired to any input-capable GPIO pin.
  • Pin labeled DT or B must be wired to any input-capable GPIO pin.

• Bare bone and funky switch type:

  • There are two pins labeled GND. The one located between A (or CLK) and B (or DT) must be wired to GND pin at the board. The other one, sometimes labeled SW GND, is not related to this subsystem.
  • Pin labeled CLK, ENCODER_A or A must be wired to any input-capable GPIO pin with internal pull-up resistors. Otherwise, a external pull-up resistor must be placed.
  • Pin labeled DT, ENCODER_B or B must be wired to any input-capable GPIO pin with internal pull-up resistors. Otherwise, a external pull-up resistor must be placed.

Signal encoding

Most encoders use "incremental Encoder Quadrature Output Waveform". This is the case of KY-040 and bare bone rotary encoders. Others seems to use a different signal encoding. This is the case of ALPS RKJX series of funky switches. Such encoding is called "alternate encoding" in this project. The firmware is ready to use both.

Firmware customization

Customization takes place at file CustomSetup.ino.

You must assign two different "input numbers" to each rotary encoder, one for clockwise rotation and another for counter-clockwise rotation. Valid input numbers are in the range of 0 to 127 (inclusive). The firmware will not boot if an invalid input number is detected.

Edit the body of simWheelSetup() and place a call to inputs::addRotaryEncoder() for each rotary encoder as shown below.

• First parameter is the GPIO assigned to CLK or A.
• Second parameter is the GPIO assigned to DT or B.
• Third parameter is the assigned input number for clockwise rotation.
• Fourth parameter is the assigned input number for counter-clockwise rotation.
• Fifth parameter must be set to true when "alternate encoding" is in place (optional parameter, defaults to false). Give a try to this parameter if your encoder does not work properly.

For example, let's say that a bare bone rotary encoder has A attached to GPIO 33 and B attached to GPIO 25:

void simWheelSetup()
{
   ...
   inputs::addRotaryEncoder(GPIO_NUM_33, GPIO_NUM_25, 30, 31);
   ...
}

For example, let's say that an ALPS funky switch encoder has ENCODER_A attached to GPIO 33 and ENCODER_B attached to GPIO 25:

void simWheelSetup()
{
   ...
   inputs::addRotaryEncoder(GPIO_NUM_33, GPIO_NUM_25, 30, 31, true);
   ...
}