ESP32: replaced the mod base circular increment

of the ADC buffer with a branch based option to avoid
the compiler to use a MOD instruction that consumes several cycles.

Signed-off-by: Felipe Neves <[email protected]>

Author: uLipe

src/current_sense/hardware_specific/esp32/esp32_mcpwm_mcu.cpp

@@ -106,7 +106,11 @@ static bool IRAM_ATTR _mcpwmTriggerADCCallback(mcpwm_timer_handle_t tim, const m
   // sample the phase currents one at a time
   // ESP's adc read takes around 10us which is very long
   // increment buffer index
-  p->buffer_index = (p->buffer_index + 1) % p->no_adc_channels;
+  p->buffer_index = (p->buffer_index + 1);
+  if(p->buffer_index == p->no_adc_channels){
+    p->buffer_index = 0;
+  }
+
   // so we are sampling one phase per call
   p->adc_buffer[p->buffer_index] = adcRead(p->pins[p->buffer_index]);