Prepare AVR and ESP FW for EnviSens

envisens/atmega_fw/atmega_fw.ino

@@ -26,6 +26,13 @@ float hmid = 0; // humidity
 float temp = 0; // temperature
 float heat = 0; // heat index
 float airq = 0; // air quality / gas 
+
+#define NUM_SENSORS 4
+float sensor_values[NUM_SENSORS];
+char sensor_names[NUM_SENSORS][5] = {"hmid", "temp", "heat", "airq"};
+int current_value_index = 0;
+
+volatile byte* float_ptr;
  
 void setup() {
   Serial.begin(SERIAL_BAUDRATE); 
@@ -38,7 +45,23 @@ void setup() {
 }
 
 void requestEvent() {
-  Wire.write("he1234");
+  byte i2c_data[8];
+  float_ptr = (byte*) &sensor_values[current_value_index];
+  i2c_data[0] = byte(sensor_names[current_value_index][0]);
+  i2c_data[1] = byte(sensor_names[current_value_index][1]);
+  i2c_data[2] = byte(sensor_names[current_value_index][2]);
+  i2c_data[3] = byte(sensor_names[current_value_index][3]);
+  i2c_data[4] = float_ptr[0];
+  i2c_data[5] = float_ptr[1];
+  i2c_data[6] = float_ptr[2];
+  i2c_data[7] = float_ptr[3]; 
+
+  Wire.write(i2c_data, 8);
+  if (current_value_index < NUM_SENSORS - 1) {
+    current_value_index ++;
+  } else {
+    current_value_index = 0;
+  }
 }
 
 void loop() {
@@ -70,5 +93,11 @@ void loop() {
     Serial.print("AirQuality: ");
     Serial.print(airq);
     Serial.println(" PPM");
+
+    // set the sensor values for global access
+    sensor_values[0] = hmid;
+    sensor_values[1] = temp;
+    sensor_values[2] = heat;
+    sensor_values[3] = airq;
   }
 }

envisens/esp_sensor_firmware/.gitignore

@@ -0,0 +1 @@
+configuration.h

envisens/esp_sensor_firmware/configuration.h.example

@@ -0,0 +1,26 @@
+/* ESP8266 environmental sensor project
+
+   This header provides the necessary credentials for the esp_sensor_firmware.ino file.
+   Before compilation, add your credentials and remove the .example postfix from the filename.
+ * ** WARNING ** DO NOT COMMIT YOUR configuration.h FILE CONTAINING YOUR ACTUAL CREDENTIALS.
+
+    (C) 2019 Macrocell - Environmental sensing solutions
+     proudly presented by Macrocell - FPGA Innovators
+*/
+
+#define sensor_id "YOUR_SENSOR_ID"
+
+#define wifi_ssid "YOUR_SSID"
+#define wifi_password "YOUR_WIFI_PW"
+
+#define mqtt_server "192.168.x.x"
+#define mqtt_port 1883
+#define mqtt_user "YOUR_MQTT_USER"
+#define mqtt_password "YOUR_MQTT_PW"
+#define mqtt_client "ESP8266Client." sensor_id
+
+#define OPERATION_BLINK_EN true // blink continuously if in correct operation
+#define OPERATION_PERIOD 5000 // sensor reading period in milliseconds 
+#define FORCE_PERIOD 12 // sensor reading publication force period in number of readings without publication 
+
+#define SERIAL_BAUDRATE 115200

envisens/esp_sensor_firmware/esp_sensor_firmware.ino

@@ -0,0 +1,181 @@
+/* Macrocell environmental sensor project EnviSens
+ *  
+ *  This firmware provides features to use the NodeMCU ESP12 unit as an environmental sensor broker.
+ *  It currently collects all the sensor information via I2C from a connected ATMEGA.
+ *  
+ *  (C) 2019 Macrocell - Environmental sensing solutions
+ *   proudly presented by Macrocell - FPGA Innovators
+ */
+
+#include <ESP8266WiFi.h>
+#include <Wire.h>
+#include <PubSubClient.h>
+#include "DHT.h"
+#include "mqtt_credentials.h"
+
+#define TOPIC_BASE "sensor/" sensor_id "/"
+#define TOPIC_TEMP TOPIC_BASE "temperature"
+#define TOPIC_HMID TOPIC_BASE "humidity"
+#define TOPIC_HEAT TOPIC_BASE "heat_index"
+#define TOPIC_AIRQ TOPIC_BASE "air_gas"
+
+#define DIFF_TEMP 0.3 // sensor has only 0.5°C accuracy, triggering on less is ludicrous
+#define DIFF_HMID 2.5 // humidity doesn't change that much anyways
+#define DIFF_HEAT 0.2 // this one's actually quite active
+#define DIFF_AIRQ 5 
+
+float hmid = 0; // humidity
+float hmid_r = 0; // humidity
+float temp = 0; // temperature
+float temp_r = 0; // temperature
+float heat = 0; // heat index
+float heat_r = 0; // heat index
+float airq = 0; // air quality / gas 
+float airq_r = 0; // air quality / gas
+
+char data[8];
+char sensor_name[5];
+float sensor_value;
+
+WiFiClient espClient;
+PubSubClient client(espClient);
+
+void setup() {
+  Serial.begin(SERIAL_BAUDRATE);
+  pinMode(LED_BUILTIN, OUTPUT); 
+  digitalWrite(LED_BUILTIN, LOW);
+  setup_wifi();
+  client.setServer(mqtt_server, mqtt_port);
+  Wire.begin();        // join i2c bus as master
+}
+
+void setup_wifi() {
+  delay(10);
+  // Connect to a WiFi network
+  Serial.println();
+  Serial.print("Connecting to ");
+  Serial.println(wifi_ssid);
+
+  WiFi.begin(wifi_ssid, wifi_password);
+  WiFi.mode(WIFI_STA);
+
+  // blink LED fast until WiFi is connected
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(200);
+    digitalWrite(LED_BUILTIN, HIGH);
+    Serial.print(".");
+    delay(200);
+    digitalWrite(LED_BUILTIN, LOW);
+  }
+
+  // WiFi connected
+  Serial.println("");
+  Serial.println("WiFi connected");
+  Serial.println("IP address: ");
+  Serial.println(WiFi.localIP());
+}
+
+void reconnect() {
+  // Loop until reconnected
+  while (!client.connected()) {
+    Serial.print("Attempting MQTT connection...");
+    // Attempt to connect
+    if (client.connect(mqtt_client, mqtt_user, mqtt_password)) {
+      Serial.println("connected");
+    } else {
+      Serial.print("failed, rc=");
+      Serial.print(client.state());
+      Serial.println(" try again in 5 seconds");
+      digitalWrite(LED_BUILTIN, HIGH);
+      // Wait 5 seconds before retrying
+      delay(4000);
+      digitalWrite(LED_BUILTIN, LOW);
+      delay(1000);
+    }
+  }
+}
+
+bool checkBound(float newValue, float prevValue, float maxDiff) {
+  return !isnan(newValue) &&
+         (newValue < prevValue - maxDiff || newValue > prevValue + maxDiff);
+}
+
+long lastMsg = 0;
+long lastSent = 0; 
+bool published = false;
+bool forcePublish = false;
+
+bool publish (String desc, char *topic, float val, float &val_r, int diff, bool force){
+    if (checkBound(val, val_r, 0.3) or force) {
+      val_r = val;
+      Serial.print("New " + desc + ": ");
+      Serial.println(String(val).c_str());
+      client.publish(topic, String(val).c_str(), true);
+      return true;
+    } else {
+      return false;
+    }
+}
+
+void loop() {
+  if (!client.connected()) {
+    reconnect();
+  }
+  client.loop();
+  digitalWrite(LED_BUILTIN, HIGH);
+
+  long now = millis();
+  if (now - lastMsg > OPERATION_PERIOD / 2) {
+    if (OPERATION_BLINK_EN) {digitalWrite(LED_BUILTIN, LOW);}
+  }
+  if (now - lastMsg > OPERATION_PERIOD) {
+    lastMsg = now;
+    if (OPERATION_BLINK_EN) {digitalWrite(LED_BUILTIN, HIGH);}
+
+    Wire.requestFrom(8, 8);    // request 6 bytes from slave device #8
+    int i = 0;
+    while(Wire.available()) {   // slave may send less than requested
+      char c =  Wire.read(); // receive a byte as character  
+      data[i] = byte(c);
+      i = i + 1;
+    }
+    
+    union sensor_tag {byte sensor_b[4]; float sensor_float;} sensor_union;       //DRPS = Drum Revs per Second
+    sensor_name[0] = char(data[0]);
+    sensor_name[1] = char(data[1]);
+    sensor_name[2] = char(data[2]);
+    sensor_name[3] = char(data[3]);
+    sensor_name[4] = 0;
+    
+    sensor_union.sensor_b[0] = data[4];
+    sensor_union.sensor_b[1] = data[5];
+    sensor_union.sensor_b[2] = data[6];
+    sensor_union.sensor_b[3] = data[7];    
+    sensor_value = sensor_union.sensor_float;
+    
+    Serial.print("Received: ");
+    Serial.print(sensor_name);
+    Serial.print(" - ");
+    Serial.println(sensor_value);
+
+    published = false;
+    if (lastSent > FORCE_PERIOD) {
+      Serial.println(F("Forcing a publish of all values"));
+      forcePublish = true;
+      lastSent = 0;
+    }
+
+    published += publish("temperature", TOPIC_TEMP, temp, temp_r, DIFF_TEMP, forcePublish);
+    published += publish("humidity", TOPIC_HMID, hmid, hmid_r, DIFF_HMID, forcePublish);
+    published += publish("heat index", TOPIC_HEAT, heat, heat_r, DIFF_HEAT, forcePublish);
+    published += publish("air quality", TOPIC_AIRQ, airq, airq_r, DIFF_AIRQ, forcePublish);
+    
+    if (published == false) {
+      lastSent = lastSent + 1;
+    } else {
+      lastSent = 0;
+    }
+    
+    forcePublish = false;
+  }
+}