My Question is How to easily invoke Simple REST Service trigerred using Arduino UNO + ESP8266 WIFI Shield programmed with AT command? I am new to this Subject and gone through many tutorial over internet but so far I could not making this working as per my requirement
My Requirement: Invoke a simple Get request originated from Arduino Uno and via ESP8266 WIFI Shield to submit to server and process the response.
What all I have done so far:
Used below Blynk example to Submit Up time to the Server and View in MobileThis is Working which means hardware setup at my side should be ok, but I dont want to Submit request to Blynk Server and I want to Submit request to my REST server and first of all I want to do a simple GET request may be to any already working API for ex: http://jsonplaceholder.typicode.com/posts/1
#define BLYNK_PRINT Serial #include <ESP8266_Lib.h> #include <BlynkSimpleShieldEsp8266.h> // You should get Auth Token in the Blynk App. // Go to the Project Settings (nut icon). char auth[] = "xyz"; // Your WiFi credentials. // Set password to "" for open networks. char ssid[] = "xyz"; char pass[] = "xyz"; // Hardware Serial on Mega, Leonardo, Micro... //#define EspSerial Serial1 // or Software Serial on Uno, Nano... #include <SoftwareSerial.h> SoftwareSerial EspSerial(2, 3); // RX, TX // Your ESP8266 baud rate: #define ESP8266_BAUD 115200 ESP8266 wifi(&EspSerial); BlynkTimer timer; void myTimerEvent() { // You can send any value at any time. // Please don't send more that 10 values per second. Blynk.virtualWrite(V5, millis() / 1000); } void setup() { // Debug console Serial.begin(115200); // Set ESP8266 baud rate EspSerial.begin(ESP8266_BAUD); delay(10); Blynk.begin(auth, wifi, ssid, pass); // You can also specify server: //Blynk.begin(auth, wifi, ssid, pass, "blynk-cloud.com", 80); //Blynk.begin(auth, wifi, ssid, pass, IPAddress(192,168,1,100), 8080); // Setup a function to be called every second timer.setInterval(1000L, myTimerEvent); } void loop() { Blynk.run(); timer.run(); // Initiates BlynkTimer }
Output :
___ __ __
/ _ )/ /_ _____ / /__
/ _ / / // / _ \/ '_/
/____/_/\_, /_//_/_/\_\
/___/ v0.6.1 on Arduino Uno
[517] Connecting to xyz
[13550] AT version:1.1.0.0(May 11 2016 18:09:56)
SDK version:1.5.4(baaea 1
[23591] Failed to connect WiFi
[31752] Ready (ping: 11ms).
[70474] Ready (ping: 12ms).
[86528] Ready (ping: 13ms).
Though I get Failed to connect to wifi but probably it retries and works there after as I can see timer in Mobile APP which is progressing.
Invoke HTTP request using AT Command, but I am getting output as ">" which I am not able to get as why the output is like this:
#include <SoftwareSerial.h> SoftwareSerial ESP8266(2, 3); String Network = "xyz"; String Password = "xyz"; void setup() { Serial.begin(9600); ESP8266.begin(115200); ESP8266.println("AT+CIOBAUD=9600"); readESP8266(4000); ESP8266.begin(9600); InitESP8266(); ConnectToWebsite(); } void loop() { while(ESP8266.available()) { Serial.println(ESP8266.readString()); } } /* Function to initialise ESP8266 */ void InitESP8266() { ESP8266.println("AT"); readESP8266(2000); ESP8266.println("AT+CWMODE=3"); //Wifi mode readESP8266(5000); ESP8266.println("AT+CWJAP=\""+ Network + "\",\"" + Password +"\""); //connect wifi readESP8266(10000); ESP8266.println("AT+CIFSR"); // IP adress readESP8266(1000); ESP8266.println("AT+CIPMUX=1"); // multiple connections readESP8266(1000); } /* Function to connect to the server */ void ConnectToWebsite() { ESP8266.println("AT+CIPSTART=1,\"TCP\",\"jsonplaceholder.typicode.com\",80"); //connect to website readESP8266(10000); ESP8266.println("AT+CIPSEND=1,114"); readESP8266(2000); String httpreq = "GET /posts/1 HTTP/1.1"; // Make a HTTP request: ESP8266.println(httpreq); readESP8266(10000); readESP8266(5000); //Serial.println("\r\n"); } //read and display message void readESP8266(const int timeout) { String reponse = ""; long int time = millis(); while( (time+timeout) > millis()) { while(ESP8266.available()) { char c = ESP8266.read(); reponse+=c; } } Serial.print(reponse); }````
Output:
OK
OK
WIFI DISCONNECT
WIFI CONNECTED
WIFI GOT IP
OK
+CIFSR:APIP,"192.168.4.1"
+CIFSR:APMAC,"abcd"
+CIFSR:STAIP,"192.168.0.169"
+CIFSR:STAMAC,"abcd"
OK
OK
1,CONNECT
OK
OK
> 1,CLOSED
If I use WIFI ESP then I am getting following error
// Emulate Serial1 on pins 6/7 if not present #ifndef HAVE_HWSERIAL1 #include "SoftwareSerial.h" SoftwareSerial Serial1(2, 3); // RX, TX #endif char ssid[] = "xyz"; // your network SSID (name) char pass[] = "xyz"; // your network password int status = WL_IDLE_STATUS; // the Wifi radio's status char server[] = "arduino.cc"; // Initialize the Ethernet client object WiFiEspClient client; void setup() { // initialize serial for debugging Serial.begin(115200); // initialize serial for ESP module Serial1.begin(9600); // initialize ESP module WiFi.init(&Serial1); // check for the presence of the shield if (WiFi.status() == WL_NO_SHIELD) { Serial.println("WiFi shield not present"); // don't continue //while (true); } // attempt to connect to WiFi network while ( status != WL_CONNECTED) { Serial.print("Attempting to connect to WPA SSID: "); Serial.println(ssid); // Connect to WPA/WPA2 network status = WiFi.begin(ssid, pass); } // you're connected now, so print out the data Serial.println("You're connected to the network"); printWifiStatus(); Serial.println(); Serial.println("Starting connection to server..."); // if you get a connection, report back via serial if (client.connect(server, 80)) { Serial.println("Connected to server"); // Make a HTTP request client.println("GET /asciilogo.txt HTTP/1.1"); client.println("Host: arduino.cc"); client.println("Connection: close"); client.println(); } } void loop() { // if there are incoming bytes available // from the server, read them and print them while (client.available()) { char c = client.read(); Serial.write(c); } // if the server's disconnected, stop the client if (!client.connected()) { Serial.println(); Serial.println("Disconnecting from server..."); client.stop(); // do nothing forevermore while (true); } } void printWifiStatus() { // print the SSID of the network you're attached to Serial.print("SSID: "); Serial.println(WiFi.SSID()); // print your WiFi shield's IP address IPAddress ip = WiFi.localIP(); Serial.print("IP Address: "); Serial.println(ip); // print the received signal strength long rssi = WiFi.RSSI(); Serial.print("Signal strength (RSSI):"); Serial.print(rssi); Serial.println(" dBm"); }````
Output:
````[WiFiEsp] I >>> TIMEOUT >>>
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] Initializing ESP module
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] Cannot initialize ESP module
[WiFiEsp] >>> TIMEOUT >>>
[WiFiEsp] No tag found
WiFi shield not present
Attempting to connect to WPA SSID: xyz
[WiFiEsp] >>> TIMEOUT >>>
Please let me know in case you figure out the issue.
lang-cpp
AT+UART=9600,8,1,0,0to set 9600 baud as default