A rotary encoder library for embedded rust applications
- Full no-std support
- Implemented with embedded-hal (https://docs.rs/embedded-hal/0.2.3/embedded_hal)
- Support for measuring angular velocity for non-linear control
Add the package via Cargo: rotary-encoder-embedded = "0.0.1"
Note: Quick example based on the stm32h7xx-hal.
static ROTARY_ENCODER: Mutex<RefCell<Option<RotaryEncoder>>> = Mutex::new(RefCell::new(None));
fn main() -> ! {
// ... Initialize DT and CLK pins as desired. Typically PullUp Push-Pull.
// ... Initialize interrupt on rising and falling edge
// ... Initialize a timer to periodically update rotary-encoder and other control systems
interrupt::free(|cs| {
ROTARY_ENCODER.borrow(cs).replace(Some(
RotaryEncoder::new(
rotary_dt,
rotary_clk,
Option::None, // optional velocity_inc_factor
Option::None, // optional velocity_dec_factor
Option::None, // optional velocity_action_ms
)
));
});
loop {}
}
#[interrupt]
fn TIM1() {
// Periodic timer update interrupt vector
interrupt::free(|cs| {
if let Some(ref mut rotary_encoder) = ROTARY_ENCODER.borrow(cs).borrow_mut().deref_mut() {
// Note: This could also be run inside the main loop.
// The rotary_encoders internal velocity is decremented by `velocity_dec_factor` when
// this function is called
rotary_encoder.tick();
}
});
}
fn handle_rotary(rotary_encoder: &mut RotaryEncoder) {
let current_time = ... // Get this NaiveDateTime based from your RTC or SysTick handler
// Update the state of the rotary-encoder, computing its current direction and angular velocity
rotary_encoder.update(current_time);
// Get the rotary values
let direction = rotary_encoder.direction();
let velocity = rotary_encoder.velocity();
if direction == Direction::Clockwise {
// Increment some value
} else if direction == Direction::AntiClockwise {
// Decrement some value
}
}
#[interrupt]
fn EXTI1() {
// DT rising or falling edge interrupt
interrupt::free(|cs| {
if let Some(ref mut rotary_encoder) = ROTARY_ENCODER.borrow(cs).borrow_mut().deref_mut() {
// Clear DT GPIO EXTI interrupt
rotary_encoder
.borrow_pins()
.0
.clear_interrupt_pending_bit();
handle_rotary(rotary_encoder);
}
});
}
#[interrupt]
fn EXTI2() {
// CLK rising or falling edge interrupt
interrupt::free(|cs| {
if let Some(ref mut rotary_encoder) = ROTARY_ENCODER.borrow(cs).borrow_mut().deref_mut() {
// Clear CLK GPIO EXTI interrupt
rotary_encoder
.borrow_pins()
.1
.clear_interrupt_pending_bit();
handle_rotary(rotary_encoder);
}
});
}