Module tca8418 

TI TCA8418 I²C keypad scanner.

The chip scans a key matrix of up to 8 rows × 10 columns on its own and queues press/release events in a 10-deep FIFO, pulling INT low while events are pending. The host only has to drain the FIFO, so a keyboard costs nothing until a key actually changes.

let mut kp = Tca8418::new(i2c, DEFAULT_ADDRESS);
kp.configure(Matrix::new(7, 8)).await?;
loop {
    int.wait_for_low().await?;
    let mut fifo = [0; FIFO_DEPTH];
    for raw in kp.drain(&mut fifo).await? {
        if let Some(Event::Key(k)) = Event::decode(*raw) { /* ... */ }
    }
    kp.clear_interrupts().await?;
}

Structs

KeyEvent

A key press or release at a position in the scan matrix.

Matrix

The rows × columns window of the chip’s pins used as a key matrix.

Tca8418

TCA8418 driver.

Enums

Event

One entry popped from the event FIFO.

Constants

DEFAULT_ADDRESS

Factory-fixed 7-bit I²C address.

FIFO_DEPTH

Depth of the on-chip event FIFO.