altos: Switch PWM constants to end up exposing µsec

This changes the constants so the clock runs at 1MHz, making the step
1µsec each. Then make the period 20000 steps, or 20ms for a 50Hz
frequency as before.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/telemega-v2.0/ao_pins.h b/src/telemega-v2.0/ao_pins.h
index a0c7cc46632e2cd6402dffb296f7dc288349d4dc..9095a350f1757713637870d80eee78220f5cf82b 100644 (file)
--- a/src/telemega-v2.0/ao_pins.h
+++ b/src/telemega-v2.0/ao_pins.h
@@ -387,10 +387,10 @@ struct ao_adc {
  */
 
 #define NUM_PWM                        4
-#define PWM_MAX                        64000
+#define PWM_MAX                        20000
 #define AO_PWM_TIMER           stm_tim4
 #define AO_PWM_TIMER_ENABLE    STM_RCC_APB1ENR_TIM4EN
-#define AO_PWM_TIMER_SCALE     10
+#define AO_PWM_TIMER_SCALE     32
 
 #define AO_PWM_0_GPIO          (&stm_gpiod)
 #define AO_PWM_0_PIN           12