StackRduino
diff --git a/‎stmhal/adc.c‎
Lines changed: 4 additions & 2 deletions b/‎stmhal/adc.c‎
Lines changed: 4 additions & 2 deletions
@@ -353,7 +353,8 @@ float adc_read_core_vbat(ADC_HandleTypeDef *adcHandle) {
     //       be 12-bits.
     raw_value <<= (12 - adc_get_resolution(adcHandle));
 
-    return raw_value * VBAT_DIV / 4096.0f * 3.3f;
+    // multiplier is 3.3/4095
+    return raw_value * VBAT_DIV * 0.8058608058608059e-3f;
 }
 
 float adc_read_core_vref(ADC_HandleTypeDef *adcHandle) {
@@ -363,7 +364,8 @@ float adc_read_core_vref(ADC_HandleTypeDef *adcHandle) {
     //       be 12-bits.
     raw_value <<= (12 - adc_get_resolution(adcHandle));
 
-    return raw_value / 4096.0f * 3.3f;
+    // multiplier is 3.3/4095
+    return raw_value * 0.8058608058608059e-3f;
 }
 #endif