synth/dsp/main.c
2021-04-24 08:57:55 -07:00

66 lines
1.4 KiB
C

#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 strlen(const char* str) {
int i = 0;
while(str[i] != '\0') {
i++;
}
return i;
}
void log(const char* stuff) {
uart_writen(uart0, stuff, strlen(stuff));
}
int main() {
init();
led0->output = 42;
while(1) {
uint8_t c = uart_read(uart0);
uint16_t period = 0;
if (c == 'c') {
led0->output = 1;
period = 1493; // C4, 262.63 Hz, maybe
log("C4\r\n");
} else if (c == 'd') {
period = 1330; // D4, 293.66 Hz, maybe
log("D4\r\n");
led0->output = 2;
} else if (c == 'e') {
period = 1185; // E4, 329.63 Hz, maybe
log("E4\r\n");
led0->output = 4;
} else if (c == 'f') {
period = 1119; // F4, 349.23 Hz, maybe
log("F4\r\n");
led0->output = 8;
} else if (c == 'g') {
period = 996; // G4, 392.00 Hz, maybe
log("G4\r\n");
led0->output = 16;
} else if (c == 'a') {
period = 887; // A4, 440.00 Hz, maybe
log("A4\r\n");
led0->output = 32;
} else if (c == 'b') {
period = 791; // B4, 493.88 Hz, maybe
log("B4\r\n");
led0->output = 64;
} else {
led0->output = 37;
}
square0->period = period;
}
}