ESP32-C6: battery voltage (ADC) feature

lyusupov · Feb 1, 2024 · f3a9ca5 · f3a9ca5
1 parent 9632a38
commit f3a9ca5
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Showing 3 changed files with 29 additions and 11 deletions.
diff --git a/software/firmware/source/SoftRF/src/platform/ESP32.cpp b/software/firmware/source/SoftRF/src/platform/ESP32.cpp
@@ -3753,7 +3753,7 @@ static void ESP32_Battery_setup()
 #elif defined(CONFIG_IDF_TARGET_ESP32C3)
     calibrate_voltage((adc1_channel_t) ADC1_GPIO1_CHANNEL);
 #elif defined(CONFIG_IDF_TARGET_ESP32C6)
-    /* TBD */
+    calibrate_voltage(SOC_GPIO_PIN_C6_BATTERY);
 #else
 #error "This ESP32 family build variant is not supported!"
 #endif /* CONFIG_IDF_TARGET_ESP32 */

diff --git a/software/firmware/source/libraries/ADC/battery.cpp b/software/firmware/source/libraries/ADC/battery.cpp
@@ -7,8 +7,28 @@
 #include "battery.h"
 
 #if defined(CONFIG_IDF_TARGET_ESP32C6)
-void calibrate_voltage(adc1_channel_t channel, adc_atten_t atten) { /* TBD */ }
-uint16_t read_voltage() { /* TBD */ return 0; }
+static uint8_t adc_pin = 1;
+
+void calibrate_voltage(uint8_t pin, adc_attenuation_t atten) {
+  adc_pin = pin;
+  analogReadResolution(12);
+  analogSetPinAttenuation(adc_pin, atten);
+}
+
+uint16_t read_voltage() {
+  // multisample ADC
+  uint32_t adc_reading = 0;
+
+  for (int i = 0; i < NO_OF_SAMPLES; i++) {
+    adc_reading += analogReadMilliVolts(adc_pin);
+    yield();
+  }
+
+  adc_reading /= NO_OF_SAMPLES;
+
+  return (uint16_t) adc_reading;
+}
+
 #else
 
 // Local logging tag

diff --git a/software/firmware/source/libraries/ADC/battery.h b/software/firmware/source/libraries/ADC/battery.h
@@ -1,20 +1,18 @@
 #ifndef _BATTERY_H
 #define _BATTERY_H
 
+uint16_t read_voltage(void);
+
 #if defined(CONFIG_IDF_TARGET_ESP32C6)
-/* TBD */
-typedef unsigned int adc1_channel_t;
-typedef unsigned int adc_atten_t;
-#define ADC_ATTEN_DB_11 0
+void calibrate_voltage(uint8_t, adc_attenuation_t atten = ADC_11db);
 #else
 #include <driver/adc.h>
 #include <esp_adc_cal.h>
+
+void calibrate_voltage(adc1_channel_t, adc_atten_t atten = ADC_ATTEN_DB_11);
 #endif /* CONFIG_IDF_TARGET_ESP32C6 */
 
 #define DEFAULT_VREF 1100 // tbd: use adc2_vref_to_gpio() for better estimate
 #define NO_OF_SAMPLES 32  // we do some multisampling to get better values
 
-uint16_t read_voltage(void);
-void calibrate_voltage(adc1_channel_t, adc_atten_t atten = ADC_ATTEN_DB_11);
-
-#endif
+#endif /* _BATTERY_H */