wetterstation: Add dew sensor

1 files changed, 45 insertions, 5 deletions

diff --git a/src/app/wetterstation/main.cc b/src/app/wetterstation/main.cc
index 2c47d78..730f47e 100644
--- a/src/app/wetterstation/main.cc
+++ b/src/app/wetterstation/main.cc
@@ -8,9 +8,14 @@ volatile uint16_t anemometer_count = 0;
 
 void loop(void)
 {
-	static uint8_t loop_count = 0;
+	static uint8_t wind_count = 0;
+	static uint8_t dew_count = 0;
 	static uint16_t anemometer_copy;
-	if (++loop_count == 10) {
+
+	wind_count++;
+	dew_count++;
+
+	if (wind_count == 10) {
 
 		cli();
 		anemometer_copy = anemometer_count;
@@ -18,7 +23,39 @@ void loop(void)
 		sei();
 
 		kout << "Anemometer Count = " << anemometer_copy << endl;
-		loop_count = 0;
+		wind_count = 0;
+	}
+
+	if (dew_count == 59) {
+		gpio.output(GPIO::pc5, 0);
+		gpio.output(GPIO::pc4, 1);
+	}
+	else if (dew_count == 60) {
+		// Measure ADC6 with AVCC reference
+		ADMUX = _BV(REFS0) | 6;
+
+		// Enable ADC with /64 prescaler
+		ADCSRA = _BV(ADEN) | _BV(ADPS2);
+
+		// Start conversion
+		ADCSRA |= _BV(ADSC);
+
+		// wait until conversion is complete
+		while (ADCSRA & _BV(ADSC)) ;
+
+		uint8_t adcr_l = ADCL;
+		uint8_t adcr_h = ADCH;
+		uint16_t dew_raw = adcr_l + (adcr_h << 8);
+		dew_raw = 1024 - dew_raw;
+
+		// Disable ADC
+		ADCSRA &= ~_BV(ADEN);
+
+		kout << "Dew Raw = " << dew_raw << endl;
+
+		dew_count = 0;
+		gpio.input(GPIO::pc5, 0);
+		gpio.input(GPIO::pc4, 0);
 	}
 }
 
@@ -28,8 +65,11 @@ int main(void)
 	gpio.setup();
 	kout.setup();
 
-	gpio.output(GPIO::pd2, 0);
-	gpio.input(GPIO::pd3, 1);
+	gpio.output(GPIO::pd2, 0); // Anemometer Reed Contact
+	gpio.input(GPIO::pd3, 1); // Anemometer Reed Contact
+
+	gpio.input(GPIO::pc5, 0); // Dew Sensor GND
+	gpio.input(GPIO::pc4, 0); // Dew Sensor VCC
 
 	EICRA = _BV(ISC11);
 	EIMSK = _BV(INT1);