Continuity and diode mode initial implementation

Reads continuity at a fixed ~100ohm or lower, and diodes with intelligent detection of LEDs vs normal diodes. Some values may need to be changed still.

include/adc.h

@@ -13,7 +13,7 @@
 
 
 
-#define ADC_CHANNELS	6
+#define ADC_CHANNELS	5
 #define ADC_HISTLEN		16
 
 
@@ -25,6 +25,8 @@ extern uint16_t adc_avg[ADC_CHANNELS];
 void adc_init();
 uint8_t adc_next();
 
+void adc_switch0();
+
 
 
 #endif /* _INC_ADC_H */