diff --git a/platformio.ini b/platformio.ini
index 4d5eb4c7..986c0d2c 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -14,7 +14,7 @@
 ;env_default = heltec
 ;env_default = ttgov1
 ;env_default = ttgov2
-;env_default = ttgov21
+env_default = ttgov21
 ;env_default = lopy
 ;env_default = lopy4
 ;env_default = fipy
diff --git a/src/adcread.cpp b/src/adcread.cpp
index 40d61161..2d3572bc 100644
--- a/src/adcread.cpp
+++ b/src/adcread.cpp
@@ -18,10 +18,6 @@
 // Local logging tag
 static const char TAG[] = "main";
 
-static const adc_channel_t channel = (adc_channel_t) HAS_BATTERY_PROBE;
-static const adc_atten_t atten = ADC_ATTEN_DB_0;
-static const adc_unit_t unit = ADC_UNIT_1;
-
 static void check_efuse()
 {
     //Check if two point calibration values are burned into eFuse
@@ -52,35 +48,31 @@ static void print_char_val_type(esp_adc_cal_value_t val_type)
 
 uint16_t read_voltage(void)
 {
+    static const adc1_channel_t channel = HAS_BATTERY_PROBE;
+    static const adc_atten_t atten = ADC_ATTEN_DB_0;
+    static const adc_unit_t unit = ADC_UNIT_1;
+
     //Check if Two Point or Vref are burned into eFuse
     check_efuse();
 
-    //Configure ADC
-    if (unit == ADC_UNIT_1) {
-        adc1_config_width(ADC_WIDTH_BIT_12);
-        adc1_config_channel_atten((adc1_channel_t)channel, atten);
-    } else {
-        adc2_config_channel_atten((adc2_channel_t)channel, atten);
-    }
+    //Configure ADC1
+    adc1_config_width(ADC_WIDTH_BIT_12);
+    adc1_config_channel_atten(channel, atten);
 
-    //Characterize ADC
+    //Characterize 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);
     print_char_val_type(val_type);
 
-    //sample ADC
+    //sample ADC1
     uint32_t adc_reading = 0;
     //Multisampling
     for (int i = 0; i < NO_OF_SAMPLES; i++) {
-        if (unit == ADC_UNIT_1) {
-            adc_reading += adc1_get_raw((adc1_channel_t)channel);
-        } else {
-            int raw;
-            adc2_get_raw((adc2_channel_t)channel, ADC_WIDTH_BIT_12, &raw);
-            adc_reading += raw;
-        }
+            adc_reading += adc1_get_raw(channel);
     }
+
     adc_reading /= NO_OF_SAMPLES;
+
     //Convert adc_reading to voltage in mV
     uint32_t voltage = esp_adc_cal_raw_to_voltage(adc_reading, adc_chars);
     ESP_LOGI(TAG,"Raw: %d\tVoltage: %dmV", adc_reading, voltage);
diff --git a/src/hal/ttgov21.h b/src/hal/ttgov21.h
index bbffce5f..af2031fe 100644
--- a/src/hal/ttgov21.h
+++ b/src/hal/ttgov21.h
@@ -5,7 +5,7 @@
 #define HAS_DISPLAY U8X8_SSD1306_128X64_NONAME_HW_I2C
 #define DISPLAY_FLIP  1 // rotated display
 #define HAS_LED 23 // green on board LED_G3 (not in initial board version)
-#define HAS_BATTERY_PROBE ADC1_GPIO35_CHANNEL // battery probe GPIO pin -> ADC_CHANNEL_7
+#define HAS_BATTERY_PROBE ADC1_GPIO35_CHANNEL // battery probe GPIO pin -> ADC1_CHANNEL_7
 
 // re-define pin definitions of pins_arduino.h
 #define PIN_SPI_SS    18 // ESP32 GPIO18 (Pin18) -- HPD13A NSS/SEL (Pin4) SPI Chip Select Input