M docs/audio_driver.md => docs/audio_driver.md +5 -0
@@ 199,6 199,11 @@ with all this information, the configuration would contain these lines:
ChibiOS uses GPIOv1 for the F103, which only knows of one alternate function.
On 'larger' STM32s, GPIOv2 or GPIOv3 are used; with them it is also necessary to configure `AUDIO_PWM_PAL_MODE` to the correct alternate function for the selected pin, timer and timer-channel.
+You can also use the Complementary output (`TIMx_CHyN`) for PWM on supported controllers. To enable this functionality, you will need to make the following changes:
+```c
+// config.h:
+#define AUDIO_PWM_COMPLEMENTARY_OUTPUT
+```
### PWM software :id=pwm-software
M platforms/chibios/drivers/audio_pwm_hardware.c => platforms/chibios/drivers/audio_pwm_hardware.c +7 -1
@@ 22,6 22,12 @@
# define AUDIO_PWM_COUNTER_FREQUENCY 100000
#endif
+#ifndef AUDIO_PWM_COMPLEMENTARY_OUTPUT
+# define AUDIO_PWM_OUTPUT_MODE PWM_OUTPUT_ACTIVE_HIGH
+#else
+# define AUDIO_PWM_OUTPUT_MODE PWM_COMPLEMENTARY_OUTPUT_ACTIVE_HIGH
+#endif
+
extern bool playing_note;
extern bool playing_melody;
extern uint8_t note_timbre;
@@ 29,7 35,7 @@ extern uint8_t note_timbre;
static PWMConfig pwmCFG = {.frequency = AUDIO_PWM_COUNTER_FREQUENCY, /* PWM clock frequency */
.period = 2,
.callback = NULL,
- .channels = {[(AUDIO_PWM_CHANNEL - 1)] = {.mode = PWM_OUTPUT_ACTIVE_HIGH, .callback = NULL}}};
+ .channels = {[(AUDIO_PWM_CHANNEL - 1)] = {.mode = AUDIO_PWM_OUTPUT_MODE, .callback = NULL}}};
static float channel_1_frequency = 0.0f;