autoplant/analog_channel_scanner/analog_channel_scanner.ino

#include <bitset>
#include <string>

// WAS D5 D6 D7
#define MULTIPLEX_PINA	17
#define MULTIPLEX_PINB	16
#define MULTIPLEX_PINC	4

// WAS A0
#define ANALOG_PIN		34

/*
000	0
001	1
010	2
011	3
100	4
101	5
110	6
111	7
*/

#define SOIL_A			4
#define SOIL_B			6
#define WATER_LEVEL_A	0
#define WATER_LEVEL_B	1


// Ref https://stackoverflow.com/a/523737/1460422
#define CHECK_BIT(var,pos) ((var) & (1<<(pos)))

float referenceVoltage = 3.3;



void read_analog(int channel) {
	
	const char* bin = std::bitset<8>(channel).to_string().c_str();
	
	bool b0 = bin[7] == u'1';
	bool b1 = bin[6] == u'1';
	bool b2 = bin[5] == u'1';
	
	Serial.print(" binary ");
	Serial.print(bin);
	Serial.print(" b2 ");
	Serial.print(b2);
	Serial.print(" b1 ");
	Serial.print(b1);
	Serial.print(" b0 ");
	Serial.print(b0);
	Serial.print(" ");
	
	digitalWrite(MULTIPLEX_PINA, b2);
	digitalWrite(MULTIPLEX_PINB, b1);
	digitalWrite(MULTIPLEX_PINC, b0);
	
	int rawValue = analogRead(ANALOG_PIN);
	float parsedValue = ((float)rawValue) / 1024.0 * referenceVoltage;
	
	Serial.print(" channel ");
	Serial.print(channel);
	Serial.print(" raw value ");
	Serial.print(rawValue);
	Serial.print(" parsed value: ");
	Serial.print(parsedValue);
	Serial.println("V");
}

void setup() {
	Serial.begin(9600);
	Serial.println("Analogue Soil Sensor Test");
	Serial.println("=========================");
	pinMode(MULTIPLEX_PINA, OUTPUT);
	pinMode(MULTIPLEX_PINB, OUTPUT);
	pinMode(MULTIPLEX_PINC, OUTPUT);
}

void loop() {
	Serial.print("C0");
	read_analog(0);
	Serial.print("C1");
	read_analog(1);
	Serial.print("C2");
	read_analog(2);
	Serial.print("C3");
	read_analog(3);
	Serial.print("C4");
	read_analog(4);
	Serial.print("C5");
	read_analog(5);
	Serial.print("C6");
	read_analog(6);
	Serial.print("C7");
	read_analog(7);
	
	
	// Serial.print("SOIL A: ");
	// read_analog(SOIL_A);
	// Serial.print("SOIL B: ");
	// read_analog(SOIL_B);
	// Serial.print("WATER LEVEL A: ");
	// read_analog(WATER_LEVEL_A);
	// Serial.print("WATER LEVEL B: ");
	// read_analog(WATER_LEVEL_B);
	
	Serial.println("\n\n\n\n\n");
	
	delay(5000);
}