Add sensor: area humidity & temp

microcontrollers/area_dht11_esp8266/area_dht11_esp8266.ino

@@ -0,0 +1,157 @@
+#include <DHTesp.h>
+#include <WiFiClient.h>
+#include <ESP8266WiFi.h>
+// NB.  We have altered the `#define MQTT_KEEPALIVE 15` in PubSubClient.h
+//      to be set as `#define MQTT_KEEPALIVE 60`.  This is done in an effort
+//      to allow the time-intensive scrolling process not take so long that
+//      it exceeds the default keepalive in PubSubClient.h.
+//      If you're using the Arduino IDE, this can usually be found in
+//      ~/Documents/Arduino/libraries/PubSubClient/PubSubClient.h
+//      WE ALSO MODIFY MQTT MAX PACKET SIZE
+//      `#define MQTT_MAX_PACKET_SIZE 256`
+#include <PubSubClient.h>
+
+
+// WARNING! YOU MUST REPLACE THE EXAMPLE VALUE BELOW
+const char* DEVICE_ID = "b1c8ae88-8622-415f-951e-27a21888fe19";
+
+
+// WIFI CONFIGURABLE CONSTANTS
+const char* ssid = "ssid";
+const char* password = "password";
+
+
+// MQTT CONFIGURABLE CONSTANTS
+const char* mqtt_broker = "broker";
+const int mqtt_port = 1883;
+const char* mqtt_topic  = "namespace/sensors";
+
+
+// WIFI VARS
+WiFiClient wifi_client;
+
+// PUBSUB VARS
+PubSubClient mqtt_client(wifi_client);
+// WARNING WARNING WARNING 
+// WARNING WARNING WARNING 
+//      PubSubClient.h must be modified to support the next setting!
+//      ~/Documents/Arduino/libraries/PubSubClient/PubSubClient.h
+//      #define MQTT_MAX_PACKET_SIZE 256
+#define MQTT_MESSAGE_SIZE 256
+char mqtt_message[MQTT_MESSAGE_SIZE];
+#define MQTT_RETRY_MS 5000
+
+// HUMIDITY & TEMP SENSOR VARS
+DHTesp dht;
+
+const int MEASUREMENT_FREQ_MS = dht.getMinimumSamplingPeriod() * 2;
+
+void setup_wifi(void) {
+  WiFi.begin(ssid, password);
+
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(333);
+    Serial.println("...waiting for Wi-Fi connection...");
+  }
+
+  Serial.println("");
+  Serial.print("Wireless network SSID: ");
+  Serial.println(ssid);
+  Serial.print("Local IP address:      ");
+  Serial.println(WiFi.localIP());
+  Serial.println("");
+}
+
+void setup_dht_sensor(void) {
+  dht.setup(D4, DHTesp::DHT11); // Connect DHT sensor to GPIO 4
+}
+
+void setup_mqtt(void) {
+  // We'll need to randomly generate a client ID later.
+  randomSeed(micros());
+
+  mqtt_client.setServer(mqtt_broker, mqtt_port);
+
+  Serial.print("Publishing to broker ");
+  Serial.print(mqtt_broker);
+  Serial.print(":");
+  Serial.print(mqtt_port);
+  Serial.print(" with topic ");
+  Serial.println(mqtt_topic);
+}
+
+
+// Thanks to https://github.com/knolleary/pubsubclient/blob/master/examples/mqtt_esp8266/mqtt_esp8266.ino
+void connect_mqtt(void) {
+  // Loop until we're connected
+  while (!mqtt_client.connected()) {
+    Serial.print("Connecting to MQTT broker...");
+    // Create a random client ID
+    String clientId = "dht11_";
+    clientId += String(random(0xffff), HEX);
+
+    // Attempt to connect
+    if (mqtt_client.connect(clientId.c_str())) {
+      Serial.println("MQTT connected");
+    } else {
+      Serial.print("MQTT connection failed, rc=");
+      Serial.print(mqtt_client.state());
+      Serial.println(" ...trying again in 5 seconds");
+
+      delay(MQTT_RETRY_MS);
+    }
+  }
+}
+
+
+void setup(void)
+{
+  Serial.begin(115200);
+
+  setup_wifi();
+
+  setup_mqtt();
+
+  setup_dht_sensor();
+
+  Serial.print("prawnalith device_id ");
+  Serial.println(DEVICE_ID);
+  Serial.println();
+  Serial.println(ARDUINO_BOARD);
+}
+
+void loop(void)
+{
+  delay(MEASUREMENT_FREQ_MS);
+
+  if (!mqtt_client.connected()) {
+    connect_mqtt();
+  }
+  mqtt_client.loop();
+
+  float humidity = dht.getHumidity();
+  float temperature = dht.getTemperature();
+
+  // publish formatted message to MQTT topic
+  snprintf(
+    mqtt_message,
+    MQTT_MESSAGE_SIZE,
+    "{ \"device_id\": \"%s\", \"status\": \"%s\", \"temp_c\": %.2f, \"temp_f\": %.2f, \"humidity\": %.2f, \"heat_index_c\": %.2f, \"heat_index_f\": %.2f }",
+    DEVICE_ID,  // snprintf wants a const char*
+    dht.getStatusString(),
+    temperature,
+    dht.toFahrenheit(temperature),
+    humidity,
+    dht.computeHeatIndex(temperature, humidity, false),
+    dht.computeHeatIndex(dht.toFahrenheit(temperature), humidity, true)
+  );
+
+  bool publish_result = mqtt_client.publish(mqtt_topic, mqtt_message);
+
+  if (!publish_result) {
+    Serial.println("MQTT publish failed.  Message too large?  Check that PubSubClient.h has the following workaround:");
+    Serial.println("#define MQTT_MAX_PACKET_SIZE 256");
+  }
+
+  Serial.println(mqtt_message);
+} 

microcontrollers/ph_temp_sensor_esp8266/ph_temp_sensor_esp8266.ino

@@ -10,6 +10,8 @@
 //      to be set as `#define MQTT_KEEPALIVE 60`.  This is done in an effort
 //      to allow the time-intensive scrolling process not take so long that
 //      it exceeds the default keepalive in PubSubClient.h.
+//      If you're using the Arduino IDE, this can usually be found in
+//      ~/Documents/Arduino/libraries/PubSubClient/PubSubClient.h
 #include <PubSubClient.h>
 
 // WIFI SETUP