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authorJack Humbert <jack.humb@gmail.com>2016-04-16 20:26:02 -0400
committerJack Humbert <jack.humb@gmail.com>2016-04-16 20:26:02 -0400
commitc83aa16f1d614c1c10f7597a67ffb9f2ae871951 (patch)
tree6d61c4f255c4ddbc98085a9758693a877e5190b5 /quantum/audio.c
parentb8d2e66638409066661e7dd3c66473d583256ec5 (diff)
fixes audio prescaler to emit correct freq
Diffstat (limited to 'quantum/audio.c')
-rw-r--r--quantum/audio.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/quantum/audio.c b/quantum/audio.c
index 5edcccdbe1..470dc8e0c7 100644
--- a/quantum/audio.c
+++ b/quantum/audio.c
@@ -12,6 +12,8 @@
#define PI 3.14159265
+#define CPU_PRESCALER 8
+
// #define PWM_AUDIO
#ifdef PWM_AUDIO
@@ -244,12 +246,12 @@ ISR(TIMER3_COMPA_vect) {
// ICR3 = (int)(((double)F_CPU) / frequency); // Set max to the period
// OCR3A = (int)(((double)F_CPU) / frequency) >> 1; // Set compare to half the period
voice_place %= voices;
- if (place > (frequencies[voice_place] / 500)) {
+ if (place > (frequencies[voice_place] / 50)) {
voice_place = (voice_place + 1) % voices;
place = 0.0;
}
- ICR3 = (int)(((double)F_CPU) / frequencies[voice_place]); // Set max to the period
- OCR3A = (int)(((double)F_CPU) / frequencies[voice_place]) >> 1 * duty_place; // Set compare to half the period
+ ICR3 = (int)(((double)F_CPU) / (frequencies[voice_place] * CPU_PRESCALER)); // Set max to the period
+ OCR3A = (int)(((double)F_CPU) / (frequencies[voice_place] * CPU_PRESCALER)) >> 1 * duty_place; // Set compare to half the period
place++;
// if (duty_counter > (frequencies[voice_place] / 500)) {
// duty_place = (duty_place % 3) + 1;
@@ -281,8 +283,8 @@ ISR(TIMER3_COMPA_vect) {
place -= SINE_LENGTH;
#else
if (note_frequency > 0) {
- ICR3 = (int)(((double)F_CPU) / note_frequency); // Set max to the period
- OCR3A = (int)(((double)F_CPU) / note_frequency) >> 1; // Set compare to half the period
+ ICR3 = (int)(((double)F_CPU) / (note_frequency * CPU_PRESCALER)); // Set max to the period
+ OCR3A = (int)(((double)F_CPU) / (note_frequency * CPU_PRESCALER)) >> 1; // Set compare to half the period
} else {
ICR3 = 0;
OCR3A = 0;