From 0a0284e616b5688a1e53c08f2edba1a51d575f8f Mon Sep 17 00:00:00 2001
From: 2EEEB <192235@vutbr.cz>
Date: Fri, 14 Feb 2020 15:58:31 +0100
Subject: [PATCH] add basic esp fw

---
 fw_esp8266.ino | 154 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 154 insertions(+)
 create mode 100644 fw_esp8266.ino

diff --git a/fw_esp8266.ino b/fw_esp8266.ino
new file mode 100644
index 0000000..27db799
--- /dev/null
+++ b/fw_esp8266.ino
@@ -0,0 +1,154 @@
+#include <ESP8266WiFi.h>
+#include "Adafruit_MQTT.h"
+#include "Adafruit_MQTT_Client.h"
+#include <NTPClient.h>
+#include <WiFiUdp.h>
+
+/************************* WiFi Settings *********************************/
+
+#define WLAN_SSID       <SSID>
+#define WLAN_PASS       <PASSWD>
+
+/************************* MQTT server settings *********************************/
+
+#define MQTT_SERVER      <SERVER>
+// Using port 8883 for MQTTS
+#define MQTT_SERVERPORT  8883
+#define MQTT_USERNAME    <USERNAME>
+#define MQTT_PASSW         <PASSWD>
+
+/***********************NTP settings*********************************/
+
+//UTC offset in seconds, 3600 for UTC+1
+#define UTC_OFFSET_S 3600
+//NTP server to use, pool is recommended
+#define NTP_SERVER "europe.pool.ntp.org"
+
+/************************* MQTT Setup ************************************/
+
+// WiFiFlientSecure for SSL/TLS support
+WiFiClientSecure client;
+
+// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
+Adafruit_MQTT_Client mqtt(&client, MQTT_SERVER, MQTT_SERVERPORT, MQTT_USERNAME, MQTT_PASSW);
+
+//mqtt server cert SHA1 fingerprint
+static const char *fingerprint PROGMEM = "10 AF 12 90 BA CA 5D B9 10 57 4C 06 96 DD 25 3B A9 09 E6 70";
+
+/****************************** MQTT Feeds ***************************************/
+
+Adafruit_MQTT_Publish test = Adafruit_MQTT_Publish(&mqtt, "test");
+
+/***************************** NTP setup *********************************/
+
+ WiFiUDP ntpUDP;
+ NTPClient timeClient(ntpUDP, NTP_SERVER, UTC_OFFSET_S);
+
+void setup() {
+    Serial.begin(115200);
+    delay(10);
+    
+    // Connect to WiFi access point.
+    Serial.println();
+    Serial.print("esp: Connecting to ");
+    Serial.println(WLAN_SSID);
+    delay(1000);
+    WiFi.begin(WLAN_SSID, WLAN_PASS);
+    delay(2000);
+ 
+    while (WiFi.status() != WL_CONNECTED) {
+        delay(500);
+        Serial.print(".");
+    }
+    Serial.println();
+    
+    Serial.println("esp: WiFi connected");
+    Serial.print("esp: IP address: "); 
+    Serial.println(WiFi.localIP());
+    
+    // check the fingerprint of SSL cert
+    client.setFingerprint(fingerprint);
+    //start NTP client
+    timeClient.begin();
+}
+
+char incoming[40];
+bool commRecvd = false;
+
+void loop() {
+    char buf;
+    static char i=0;
+    
+    MQTT_connect(); //Keep mqtt connection alive
+    
+    while(Serial.available() > 0) {
+    buf = Serial.read();
+    if(buf != '\n') {
+      incoming[i] = buf;
+      i++;
+    }
+    else {
+      incoming[i] = '\0';
+      commRecvd = true;
+    }
+    }
+
+    i = 0;
+  
+    if(commRecvd == true){
+        if(strcmp("?ntp", incoming) == 0){  //if request for time update received, process time update
+            while(!timeClient.update()){ //update from ntp server
+                delay(10); //time sync is critical, wait for succesful update
+            };
+            Serial.print(">");     //indicate time data
+            Serial.print(timeClient.getYear());
+            Serial.print(",");
+            Serial.print(timeClient.getMonth());
+            Serial.print(",");
+            Serial.print(timeClient.getDate());
+            Serial.print(",");
+            Serial.print(timeClient.getHours());
+            Serial.print(",");
+            Serial.print(timeClient.getMinutes());
+            Serial.print(",");
+            Serial.print(timeClient.getSeconds());
+            Serial.print('\n');
+            delay(1000); //give time to process comm
+            } else {
+            Serial.print("esp: recvd: ");
+            Serial.println(incoming);
+            test.publish(incoming);
+            Serial.println("esp: sent data");
+        };
+        commRecvd = false;
+    }
+        delay(100);;
+}
+
+// Function to connect and reconnect as necessary to the MQTT server.
+// Borrowed from Adafruit MQTT lib example.
+void MQTT_connect() {
+    int8_t ret;
+    
+    // Stop if already connected.
+    if (mqtt.connected()) {
+        return;
+    }
+    
+    Serial.print("Connecting to MQTT... ");
+
+    uint8_t retries = 3;
+    while ((ret = mqtt.connect()) != 0) {   // connect will return 0 for connected
+        Serial.print("esp: ");
+        Serial.println(mqtt.connectErrorString(ret));
+        Serial.println("esp: Retrying MQTT connection in 5 seconds...");
+        mqtt.disconnect();
+        delay(5000);  // wait 5 seconds
+        retries--;
+        if (retries == 0) {
+             // basically die and wait for WDT to reset me
+             while (1);
+        }
+    }
+    Serial.println("MQTT Connected!");
+}