Update variant.h

variants/heltec_v2/variant.h

@@ -24,18 +24,20 @@
 #define LORA_DIO1 35 // Not really used
 #define LORA_DIO2 34 // Not really used
 
-// ratio of voltage divider = 3.20 (R1=100k, R2=220k)
-#define ADC_MULTIPLIER 3.2
 
 #ifdef HELTEC_V2_0
 
+// ratio of voltage divider = 3.20 (R1=100k, R2=220k)
+#define ADC_MULTIPLIER 3.2
 #define BATTERY_PIN 13 // A battery voltage measurement pin, voltage divider connected here to measure battery voltage
 
 #endif
 
 #ifdef HELTEC_V2_1
 
+// multiplier can differentiate between 3.5 to 3.75
+#define ADC_MULTIPLIER 3.6 // arbitrary value that will be ok for most devices
 #define BATTERY_PIN 37 // A battery voltage measurement pin, voltage divider connected here to measure battery voltage
 #define EXT_NOTIFY_OUT 13 // Default pin to use for Ext Notify Plugin.
 
-#endif
+#endif