#include "sys.h" void init() { square0->output_address = pdmout0; square0->high_val = 0xffff; square0->low_val = 0x0000; square0->flags = SQUARE_FLAG_ENABLE_msk; // will set the period later } int main() { init(); while(1) { uint8_t c = uart_read(uart0); uint16_t period; if (c == 'c') { period = 1493; // C4, 262.63 Hz, maybe } else if (c == 'd') { period = 1330; // D4, 293.66 Hz, maybe } else if (c == 'e') { period = 1185; // E4, 329.63 Hz, maybe } else if (c == 'f') { period = 1119; // F4, 249.23 Hz, maybe } else if (c == 'g') { period = 996; // G4, 392.00 Hz, maybe } else if (c == 'a') { period = 887; // A4, 440.00 Hz, maybe } else if (c == 'b') { period = 791; // B4, 493.88 Hz, maybe } square0->period = period; } }