stuartl/atinysynth
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attiny85: Add ADC-based keyboard support.

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This is a work-in-progress, but we're now able to play some notes by
pressing keys.
This commit is contained in:
Stuart Longland 2017-05-01 17:38:17 +10:00
parent 3ff3e349f5
commit 6ddaad18f2
Signed by: stuartl
GPG Key ID: F954BBBB7948D546
1 changed files with 43 additions and 12 deletions
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55
ports/attiny85/main.c
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@ -19,6 +19,8 @@
*/
#include "synth.h"
#include "adckbd.h"
#include <string.h>
#include <avr/io.h>
#include <util/delay.h>
@ -34,9 +36,11 @@ int main(void) {
synth.enable = 0;
synth.mute = 0;
adckbd_init();
/* Enable output on PB4 (PWM out) */
DDRB |= (1 << 4) | (1 << 3);
PORTB &= ~((1 << 4) | (1 << 3));
DDRB |= (1 << 4) | (1 << 0) | (1 << 1) | (1 << 2);
PORTB &= ~((1 << 4) | (1 << 0) | (1 << 1) | (1 << 2));
/* Timer 1 configuration for PWM */
OCR1B = 128; /* Initial PWM value */
@ -53,21 +57,48 @@ int main(void) {
TIMSK |= (1 << OCIE0A); /* Enable interrupts */
/* Configure the synthesizer */
voice_wf_set_triangle(&poly_voice[0].wf, 1000, 127);
voice_wf_set_triangle(&poly_voice[1].wf, 1200, 127);
voice_wf_set_triangle(&poly_voice[0].wf, 523, 63);
voice_wf_set_triangle(&poly_voice[1].wf, 659, 63);
voice_wf_set_triangle(&poly_voice[2].wf, 784, 63);
voice_wf_set_triangle(&poly_voice[3].wf, 880, 63);
adsr_config(&poly_voice[0].adsr,
200, 30, 10, 10, 10, 10, 255, 192);
100, 0, 10, 10, 10, 10, 255, 192);
adsr_config(&poly_voice[1].adsr,
200, 0, 10, 10, 10, 10, 255, 192);
synth.enable = 3;
100, 0, 10, 10, 10, 10, 255, 192);
adsr_config(&poly_voice[2].adsr,
100, 0, 10, 10, 10, 10, 255, 192);
adsr_config(&poly_voice[3].adsr,
100, 0, 10, 10, 10, 10, 255, 192);
synth.enable = 0x0;
sei();
while(1) {
if (!synth.enable) {
adsr_reset(&poly_voice[0].adsr);
adsr_reset(&poly_voice[1].adsr);
synth.enable = 3;
PORTB ^= (1 << 3);
PORTB ^= (1 << 0);
if (adckbd_now & ADCKBD_CHANGED) {
uint8_t btn = 0;
uint8_t voice = 0;
for (btn = ADCKBD_PRESSED(0), voice = 0;
btn & ADCKBD_ALL;
btn <<= 1, voice++) {
PORTB ^= (1 << 2);
/* Is it pressed now? */
if (!(adckbd_now & btn))
continue;
/* Was it pressed before? */
if (!(adckbd_diff & btn))
continue;
adsr_reset(&poly_voice[voice].adsr);
synth.enable |= btn;
/* Acknowledge key */
adckbd_now &= ~btn;
}
/* Acknowledge changes */
adckbd_now &= ~ADCKBD_CHANGED;
PORTB ^= (1 << 1);
}
}
return 0;