i have to paste the url generated in the output ide everytime to get the data on my thingspeak channel: e,g.: http://api.thingspeak.com/update?api_key=***REDACTED***&field1=27.25&field2=3.27&field3=0.00 my code is : #include "DHT.h" #define DHTPIN 15 // Pin where DHT sensor is connected #define DHTTYPE DHT11 DHT dht(DHTPIN, DHTTYPE); #define THINGSPEAK_API_KEY "***REDACTED***" #include <SoftwareSerial.h> #include <OneWire.h> #include <DallasTemperature.h> #include <ArduinoJson.h> SoftwareSerial myserial(10, 11); // RX, TX for GSM communication // Temperature Sensor Setup #define ONE_WIRE_BUS 5 OneWire oneWire(ONE_WIRE_BUS); DallasTemperature sensors(&oneWire); // Flow Sensor Setup #define SENSOR_PIN 2 volatile byte pulseCount = 0; float flowRate = 0.0; unsigned int flowMilliLitres = 0; unsigned long totalMilliLitres = 0; unsigned long oldTime = 0; float calibrationFactor = 5.5; // Calibration factor for flow meter // Turbidity Sensor Setup int turbiditySensorValue; float voltage; // Variables for DHT sensor float temperatureC; float temperatureF; void setup() { Serial.begin(9600); myserial.begin(9600); pinMode(SENSOR_PIN, INPUT); digitalWrite(SENSOR_PIN, HIGH); pulseCount = 0; flowRate = 0.0; flowMilliLitres = 0; totalMilliLitres = 0; oldTime = 0; attachInterrupt(digitalPinToInterrupt(SENSOR_PIN), pulseCounter, FALLING); sensors.begin(); // Initialize temperature sensor dht.begin(); // Initialize DHT sensor // GSM Initialization with better error checking initGSM(); } void initGSM() { Serial.println("Initializing GSM..."); // Wait for GSM module to respond while (!sendATCommand("AT", "OK", 1000)) { Serial.println("Waiting for GSM module..."); delay(1000); } sendATCommand("AT+SAPBR=3,1,\"Contype\",\"GPRS\"", "OK", 2000); sendATCommand("AT+SAPBR=3,1,\"APN\",\"your_apn\"", "OK", 2000); // Change APN if needed sendATCommand("AT+SAPBR=1,1", "OK", 2000); sendATCommand("AT+SAPBR=2,1", "OK", 2000); } bool sendATCommand(const char* command, const char* expected_answer, unsigned int timeout) { Serial.println("Sending command: " + String(command)); myserial.println(command); String response = ""; unsigned long previous = millis(); while (millis() - previous < timeout) { while (myserial.available()) { char c = myserial.read(); response += c; } if (response.indexOf(expected_answer) >= 0) { Serial.println("Response: " + response); // Print full response return true; } } Serial.println("Timeout! No response or unexpected response: " + response); return false; } void loop() { flowMeter(); temperature(); turbidity(); sendToThingSpeak(); delay(15000); // 15 second delay between readings } void flowMeter() { if ((millis() - oldTime) > 1000) { detachInterrupt(digitalPinToInterrupt(SENSOR_PIN)); flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor; oldTime = millis(); flowMilliLitres = (flowRate / 60) * 1000; totalMilliLitres += flowMilliLitres; Serial.print("Flow rate: "); Serial.print(flowRate, 2); // Print with 2 decimal places Serial.println(" L/min"); pulseCount = 0; attachInterrupt(digitalPinToInterrupt(SENSOR_PIN), pulseCounter, FALLING); } } void pulseCounter() { pulseCount++; } void temperature() { sensors.requestTemperatures(); temperatureC = sensors.getTempCByIndex(0); temperatureF = sensors.toFahrenheit(temperatureC); Serial.print("Temperature: "); Serial.print(temperatureC); Serial.println("°C"); } void turbidity() { turbiditySensorValue = analogRead(A0); voltage = turbiditySensorValue * (5.0 / 1024.0); Serial.print("Turbidity Voltage: "); Serial.println(voltage, 2); // Print with 2 decimal places } void sendToThingSpeak() { // Check if GSM is connected if (!sendATCommand("AT+SAPBR=2,1", "OK", 2000)) { Serial.println("GSM Network Issue! Not sending data."); return; } // Close any existing HTTP connection sendATCommand("AT+HTTPTERM", "OK", 1000); delay(1000); // Initialize HTTP service if (!sendATCommand("AT+HTTPINIT", "OK", 2000)) { Serial.println("HTTP init failed"); return; } sendATCommand("AT+HTTPPARA=\"CID\",1", "OK", 1000); // Construct URL properly String url = "http://api.thingspeak.com/update?api_key="; url += THINGSPEAK_API_KEY; url += "&field1=" + String(temperatureC); url += "&field2=" + String(voltage); url += "&field3=" + String(flowRate); Serial.println("Generated URL: " + url); // Print full URL before sending // Send URL parameter properly String command = "AT+HTTPPARA=\"URL\",\"" + url + "\""; if (!sendATCommand(command.c_str(), "OK", 2000)) { Serial.println("Setting URL failed"); return; } // Start HTTP GET request if (!sendATCommand("AT+HTTPACTION=0", "+HTTPACTION: 0,200", 5000)) { Serial.println("HTTP GET command failed"); return; } delay(5000); // Wait for response // Read HTTP response if (!sendATCommand("AT+HTTPREAD", "OK", 5000)) { Serial.println("Failed to read HTTP response"); return; } Serial.println("Data sent successfully!"); // Close HTTP connection sendATCommand("AT+HTTPTERM", "OK", 1000); }
All technical questions
View all files
