Implement multiple sensors reading for moisture

src/atmega/config.h

@@ -9,10 +9,11 @@
 #define MOISTURE_SENSOR_A5 PC5
 // NOTE: PC6 PC7 are not accessible by default on Arduino Uno R3
 // You need to use the ATMega328p on a custom PCB and use pins 1 and 2
-#define MOISTURE_SENSOR_A6 PC6
-#define MOISTURE_SENSOR_A7 PC7
+//#define MOISTURE_SENSOR_A6 PC6
+//#define MOISTURE_SENSOR_A7 PC7
 
 
 #define SENSOR_READINGS 5
+#define SENSORS_NUM 6
 
 #endif

src/atmega/main.c

@@ -4,9 +4,10 @@
 #include <avr/wdt.h>
 #include <avr/interrupt.h>
 #include "moisture.h"
+#include "adc.h"
 
 ISR(WDT_vect) {
-    readSensors = true;
+    triggerSensorsRead();
 }
 
 void watchdogs(void) {
@@ -25,7 +26,8 @@ void enterSleep(void) {
 }
 
 void setup(void) {
-    initMoistureSensor();
+    adcInit();
+    initMoistureSensors();
     watchdogs();
 }
 
@@ -33,13 +35,10 @@ int main(void) {
     setup();
 
     while(true) {
-
         if (readSensors) {
             int16_t result = readMoisture();
-            if (result != -1) {
-                //Serial.println(result);
-                readSensors = false;
-            }
+
+            //TODO: send result to esp32
         }
         enterSleep();
     }

src/atmega/moisture.c

@@ -6,36 +6,57 @@
 #include "config.h"
 #include "adc.h"
 
-static int16_t moistureReadingSum = 0;
-static int8_t moistureReadingCount = 0;
-
 volatile bool readSensors = false;
 
-void initMoistureSensor(void) {
-    DDRC &= ~(1 << MOISTURE_SENSOR_A0); // set as input
-    PORTC &= ~(1 << MOISTURE_SENSOR_A0); //disable pullup
+void initMoistureSensors(void) {
+    // Set as input
+    DDRC &= ~((1 << MOISTURE_SENSOR_A0) |
+              (1 << MOISTURE_SENSOR_A1) |
+              (1 << MOISTURE_SENSOR_A2) |
+              (1 << MOISTURE_SENSOR_A3) |
+              (1 << MOISTURE_SENSOR_A4) |
+              (1 << MOISTURE_SENSOR_A5)) ;
+              //(1 << MOISTURE_SENSOR_A6) |
+              //(1 << MOISTURE_SENSOR_A7));
+    // Disable pullup
+    PORTC &= ~((1 << MOISTURE_SENSOR_A0) |
+               (1 << MOISTURE_SENSOR_A1) |
+               (1 << MOISTURE_SENSOR_A2) |
+               (1 << MOISTURE_SENSOR_A3) |
+               (1 << MOISTURE_SENSOR_A4) |
+               (1 << MOISTURE_SENSOR_A5)) ;
+               //(1 << MOISTURE_SENSOR_A6) |
+               //(1 << MOISTURE_SENSOR_A7));
 }
 
-void triggerSensorRead(void) {
+void triggerSensorsRead(void) {
     readSensors = true;
 }
 
-int16_t readMoisture(void) {
-    if (!readSensors)
-        return -1;
-
-    adcInit();
-    moistureReadingSum += adcRead(MOISTURE_SENSOR_A0);
-    moistureReadingCount++;
-
-    //TODO: implement variance check (if over a certain variance discard measurements for this cicle)
-    if (moistureReadingCount >= SENSOR_READINGS) {
-        int16_t average = moistureReadingSum / SENSOR_READINGS;
-        moistureReadingSum = 0;
-        moistureReadingCount = 0;
-        readSensors = false;
-        return average;
-    } else readSensors = true;
-
-    return -1;
+int16_t moistureSensorsAverage(int8_t sensorPin) {
+    int16_t sum = 0;
+    for (int i = 0; i < SENSOR_READINGS; i++) {
+        sum += adcRead(sensorPin);
+        //TODO: implement variance check (if over a certain variance discard measurements for this cycle)
+        //TODO: maybe add a small delay using watchdog here?
+        //TODO IMPORTANT: if value < 1 or > 1022, discard that measurement
+    }
+    return sum / SENSOR_READINGS;
+}
+
+int16_t readMoisture(void) {
+    uint8_t sensorPins[SENSORS_NUM] = { MOISTURE_SENSOR_A0, MOISTURE_SENSOR_A1,
+                                        MOISTURE_SENSOR_A2, MOISTURE_SENSOR_A3,
+                                        MOISTURE_SENSOR_A4, MOISTURE_SENSOR_A5 };
+                                        //MOISTURE_SENSOR_A6, MOISTURE_SENSOR_A7 };
+
+    int16_t overallSum = 0;
+
+    for (int i = 0; i < SENSORS_NUM; i++) {
+        int16_t sensorAverage = moistureSensorsAverage(sensorPins[i]);
+        //TODO: if a sensor gives 0 or 1023, discard that sensor entirely (means it is disconnected or not working)
+        overallSum += sensorAverage;
+    }
+
+    return overallSum / SENSORS_NUM;
 }

src/atmega/moisture.h

@@ -4,9 +4,10 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-void initMoistureSensor(void);
+void initMoistureSensors(void);
+void triggerSensorsRead(void);
+int16_t moistureSensorsAverage(int8_t sensorPin);
 int16_t readMoisture(void);
-void triggerSensorRead(void);
 
 extern volatile bool readSensors;