Struct ShiftRegisterMatrix 

pub struct ShiftRegisterMatrix<S: SpiDevice, IP: InputPin, T: Fn(usize, usize) -> Option<(usize, usize)>, const OUTPUT_PIN_COUNT: usize, const INPUT_PIN_COUNT: usize, const ROWS: usize, const COLS: usize> { /* private fields */ }

Matrix scanner using spi-like shift register such as 74HC595 as output pin.

NOTE: Currently, chained shift register is not supported and OUTPUT_PIN_COUNT must be number of 1 to 8.

Implementations

impl<S: SpiDevice, IP: InputPin, T: Fn(usize, usize) -> Option<(usize, usize)>, const OUTPUT_PIN_COUNT: usize, const INPUT_PIN_COUNT: usize, const ROWS: usize, const COLS: usize> ShiftRegisterMatrix<S, IP, T, OUTPUT_PIN_COUNT, INPUT_PIN_COUNT, ROWS, COLS>

pub fn new( row_shift_register: S, input_pins: [IP; INPUT_PIN_COUNT], map_key_pos: T, scan_delay: Option<Duration>, ) -> Self

Initialize the scanner.

WARNING: Shift register is not actually spi so you should set proper spi mode. Also, the scan direction can be different depending spi mode.

• row_shift_register: SPI bus for the shift register used as output pin.
• input_pins: Input pins to read the matrix.
• map_key_pos: Function to map key position from pin number. This function must return position within specified ROWS and COLS. Signature: (row, col) -> Option<(row, col)>
• scan_delay: Delay between output pin change and input read. This is executed for each col/row so, this should be short enough to scan the matrix in a reasonable time. (Default: 5us)

Trait Implementations

impl<S: SpiDevice, IP: InputPin, T: Fn(usize, usize) -> Option<(usize, usize)>, const OUTPUT_PIN_COUNT: usize, const INPUT_PIN_COUNT: usize, const ROWS: usize, const COLS: usize> KeyscanDriver for ShiftRegisterMatrix<S, IP, T, OUTPUT_PIN_COUNT, INPUT_PIN_COUNT, ROWS, COLS>

async fn scan(&mut self, cb: impl FnMut(KeyChangeEvent))

Scans a key and returns the delta from the previous key scan