.program matrix
; INPUT: repeated bit pattern
; 0000_0100_0000_1000_0001_0000_0010_0000_0100_0000_1000_0001_0000_0000_0000_0000
; So, like: 0x0408_1020, 0x4081_0000
  set x, 7
loop:
  pull ifempty [31]
  ; Assert the column pins
  out pins, 8 [31]
  ; Read the row pins
  in pins, 5 [31]
  jmp x--, loop [31]
  ; Output the two missing bits and push
  in null, 2 [31]
  push [31]

% c-sdk {
static inline void matrix_program_init(PIO pio, uint sm, uint offset, uint pin) {
    pio_sm_config c = matrix_program_get_default_config(offset);

    // The row inputs start at the pin base
    sm_config_set_in_pins(&c, pin);
    // The 6 output bits come after the 5 input bits
    sm_config_set_out_pins(&c, pin + 5, 6);
    // Set up the pins for PIO
    for(int i = 0; i < 11; i++)
        pio_gpio_init(pio, pin + i);
    // Set the pin directions
    pio_sm_set_consecutive_pindirs(pio, sm, pin, 5, false);
    pio_sm_set_consecutive_pindirs(pio, sm, pin + 5, 6, true);

    // Load our configuration, and jump to the start of the program
    pio_sm_init(pio, sm, offset, &c);
    // Set the state machine running
    pio_sm_set_enabled(pio, sm, true);
}
%}