A rotary encoder library for embedded rust applications
no-stdsupport- Suitable for gray-code incremental encoders
- Implemented with embedded-hal (https://docs.rs/embedded-hal/0.2.7/embedded_hal)
The RotaryEncoder can operate in a number of different modes, these modes provide different types of feature sets and are individually gated behind feature flags to keep the binary size to a minimum.
The following modes are currently p
6BF0
rovided:
| Feature flag | Mode | Desc. |
|---|---|---|
standard |
StandardMode |
Uses a state machine for transitions |
angular-velocity |
AngularVelocityMode |
Same as standard but with additional angular-velocity calculations |
fn main() -> ! {
// Configure DT and CLK pins, typically pullup input
let rotary_dt = gpio_pin_1.into_pull_up_input()
let rotary_clk = gpio_pin_2.into_pull_up_input();
// Initialize the rotary encoder
let mut rotary_encoder = RotaryEncoder::new(
rotary_dt,
rotary_clk,
).into_standard_mode();
// ...timer initialize at 900Hz to poll the rotary encoder
loop {}
}
fn timer_interrupt_handler() {
// ... get rotary encoder
let rotary_encoder = ...
// Update the encoder, which will compute its direction
rotary_encoder.update();
match rotary_encoder.direction() {
Direction::Clockwise => {
// Increment some value
}
Direction::Anticlockwise => {
// Decrement some value
}
Direction::None => {
// Do nothing
}
}
}I've experimented a lot with different combinations in order to make Rotary Encoders behave predictably because generally speaking they are fickle at best. From my experimentation I've learnt that using GPIO pin based interrupts generally isn't a good idea because they are more prone to noise and increase the risk of misfires and jumps. Timers on the other hand provide a low pass filtering quality because they don't pick up higher frequency switching that GPIO interrupts do. I have found that using a Timer between 850-1000Hz seems to work best.