bugfix RAM issue in battery monitor

src/battery.cpp

@@ -5,50 +5,48 @@
 // Local logging tag
 static const char TAG[] = "main";
 
-static void print_char_val_type(esp_adc_cal_value_t val_type) {
+esp_adc_cal_characteristics_t *adc_characs =
-  if (val_type == ESP_ADC_CAL_VAL_EFUSE_TP) {
+    (esp_adc_cal_characteristics_t *)calloc(
-    ESP_LOGD(TAG,
+        1, sizeof(esp_adc_cal_characteristics_t));
-             "ADC characterization based on Two Point values stored in eFuse");
-  } else if (val_type == ESP_ADC_CAL_VAL_EFUSE_VREF) {
-    ESP_LOGD(TAG,
-             "ADC characterization based on reference voltage stored in eFuse");
-  } else {
-    ESP_LOGD(TAG, "ADC characterization based on default reference voltage");
-  }
-}
 
-uint16_t read_voltage(void) {
+static const adc1_channel_t adc_channel = HAS_BATTERY_PROBE;
-  static const adc1_channel_t channel = HAS_BATTERY_PROBE;
 static const adc_atten_t atten = ADC_ATTEN_DB_11;
 static const adc_unit_t unit = ADC_UNIT_1;
 
-  // configure ADC1
+void calibrate_voltage(void) {
+  // configure ADC
   ESP_ERROR_CHECK(adc1_config_width(ADC_WIDTH_BIT_12));
-  ESP_ERROR_CHECK(adc1_config_channel_atten(channel, atten));
+  ESP_ERROR_CHECK(adc1_config_channel_atten(adc_channel, atten));
-
+  // calibrate ADC
-  // calibrate ADC1
-  esp_adc_cal_characteristics_t *adc_chars =
-      (esp_adc_cal_characteristics_t *)calloc(
-          1, sizeof(esp_adc_cal_characteristics_t));
   esp_adc_cal_value_t val_type = esp_adc_cal_characterize(
-      unit, atten, ADC_WIDTH_BIT_12, DEFAULT_VREF, adc_chars);
+      unit, atten, ADC_WIDTH_BIT_12, DEFAULT_VREF, adc_characs);
-  print_char_val_type(val_type);
+  // show ADC characterization base
-
+  if (val_type == ESP_ADC_CAL_VAL_EFUSE_TP) {
-  // multisample ADC1
+    ESP_LOGI(TAG,
-  uint32_t adc_reading = 0;
+             "ADC characterization based on Two Point values stored in eFuse");
-  for (int i = 0; i < NO_OF_SAMPLES; i++) {
+  } else if (val_type == ESP_ADC_CAL_VAL_EFUSE_VREF) {
-    adc_reading += adc1_get_raw(channel);
+    ESP_LOGI(TAG,
+             "ADC characterization based on reference voltage stored in eFuse");
+  } else {
+    ESP_LOGI(TAG, "ADC characterization based on default reference voltage");
+  }
 }
 
+uint16_t read_voltage() {
+  // multisample ADC
+  uint32_t adc_reading = 0;
+  for (int i = 0; i < NO_OF_SAMPLES; i++) {
+    adc_reading += adc1_get_raw(adc_channel);
+  }
   adc_reading /= NO_OF_SAMPLES;
-
+  // Convert ADC reading to voltage in mV
-  // Convert adc_reading to voltage in mV
   uint16_t voltage =
-      (uint16_t)esp_adc_cal_raw_to_voltage(adc_reading, adc_chars);
+      (uint16_t)esp_adc_cal_raw_to_voltage(adc_reading, adc_characs);
 #ifdef BATT_FACTOR
   voltage *= BATT_FACTOR;
 #endif
-  ESP_LOGD(TAG, "Raw: %d / Voltage: %dmV", adc_reading, voltage);
+  ESP_LOGI(TAG, "Raw: %d / Voltage: %dmV", adc_reading, voltage);
   return voltage;
 }
+
 #endif // HAS_BATTERY_PROBE

src/battery.h

@@ -5,8 +5,9 @@
 #include <esp_adc_cal.h>
 
 #define DEFAULT_VREF 1100 // tbd: use adc2_vref_to_gpio() for better estimate
-#define NO_OF_SAMPLES 64  // we do multisampling
+#define NO_OF_SAMPLES 64  // we do some multisampling to get better values
 
 uint16_t read_voltage(void);
+void calibrate_voltage(void);
 
 #endif

src/main.cpp

@@ -332,6 +332,7 @@ void setup() {
 // initialize battery status if present
 #ifdef HAS_BATTERY_PROBE
   strcat_P(features, " BATT");
+  calibrate_voltage();
   batt_voltage = read_voltage();
 #endif
 
@@ -370,7 +371,7 @@ void setup() {
 #ifdef HAS_BATTERY_PROBE
   battCycle = timerBegin(3, 8000, true);
   timerAttachInterrupt(battCycle, &BattCycleIRQ, true);
-  timerAlarmWrite(battCycle, 60 * 100, true);
+  timerAlarmWrite(battCycle, BATTREADCYCLE * 10000, true);
   timerAlarmEnable(battCycle);
 #endif
 

src/paxcounter.conf

@@ -58,11 +58,10 @@
 #define BUTTONPORT                      5       // Port on which device sends button pressed signal
 #define CAYENNEPORT                     2       // Port for Cayenne LPP 2.0 packet sensor encoding
 
-// Default RGB LED luminosity (in %)
+// Some hardware settings
-#define RGBLUMINOSITY                   30      // 30%
+#define RGBLUMINOSITY                   30      // RGB LED luminosity [default = 30%]
-
+#define DISPLAYREFRESH_MS               40      // OLED refresh cycle in ms [default = 40] -> 1000/40 = 25 frames per second
-// OLED Display refresh cycle (in Milliseconds)
+#define BATTREADCYCLE                   60      // battery measuring cycle in seconds [default = 60 secs]
-#define DISPLAYREFRESH_MS               40      // e.g. 40ms -> 1000/40 = 25 frames per second
 
 // LMIC settings
 // define hardware independent LMIC settings here, settings of standard library in /lmic/config.h will be ignored