Send a temperature from ESP8266 to DummySensor in Domoticz

[rienwoerd]

I've searched the internet for a long time, but I can't find it. Is it already available somewhere, or can anyone help me?

The problem lies with the connection from Arduino to Domoticz. In an Arduino program, I want to send the following to a DummySensor in Domoticz:

http://192.168.178.170:8080/json.htm?type=command&param=udevice&idx=335&nvalue=0&svalue=22&passcode=domoticz

This works perfectly when I enter it directly into the browser, but I have no idea how to do that in Arduino.
Can anyone help me with a hint on how to do that or where I can find it?

Thanx, Rien

[IasminMoreira]

Você pode usar a biblioteca WiFi.h + HTTPClient.h (para ESP32/ESP8266):

#include <WiFi.h>
#include <HTTPClient.h>

const char* ssid = "SEU_WIFI";
const char* password = "SUA_SENHA";

void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) delay(500);
}

void loop() {
if (WiFi.status() == WL_CONNECTED) {
HTTPClient http;
http.begin("http://192.168.178.170:8080/json.htm?type=command&m=udevice&idx=335&nvalue=0&svalue=22&passcode=domoticz");
int httpCode = http.GET();
Serial.println(httpCode);
http.end();
}
delay(10000);
}

[Paramveersingh-S]

You're close! A couple of things to fix from the existing reply — it uses ESP32's <WiFi.h> (won't compile on ESP8266) and has a typo: m=udevice should be param=udevice, matching your working browser URL exactly.
Here's a version for the ESP8266 core that sends a real temperature reading:
cpp#include <ESP8266WiFi.h>
#include <ESP8266HTTPClient.h>
#include <WiFiClient.h>

const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";

const char* domoticzHost = "192.168.178.170";
const int domoticzPort = 8080;
const int idx = 335; // your DummySensor idx

void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);

Serial.print("Connecting to WiFi");
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println("\nConnected, IP: " + WiFi.localIP().toString());
}

void sendTemperature(float temperature) {
if (WiFi.status() != WL_CONNECTED) {
Serial.println("WiFi not connected, skipping send");
return;
}

WiFiClient client;
HTTPClient http;

String url = "http://" + String(domoticzHost) + ":" + String(domoticzPort) +
"/json.htm?type=command&param=udevice&idx=" + String(idx) +
"&nvalue=0&svalue=" + String(temperature, 1) +
"&passcode=domoticz";

http.begin(client, url);
int httpCode = http.GET();

if (httpCode > 0) {
Serial.printf("Domoticz response code: %d\n", httpCode);
Serial.println(http.getString());
} else {
Serial.printf("HTTP GET failed: %s\n", http.errorToString(httpCode).c_str());
}

http.end();
}

void loop() {
// Replace this with your actual sensor read, e.g. DHT/DS18B20
float temperature = readTemperature();
sendTemperature(temperature);
delay(60000); // send once a minute; 10s is usually too aggressive for Domoticz
}
Key differences from the earlier reply, and why they matter:

ESP8266WiFi.h/ESP8266HTTPClient.h instead of ESP32's WiFi.h — this is the ESP8266 Arduino core repo, so the ESP32 headers won't even compile here.
http.begin(client, url) — on the ESP8266 core, HTTPClient::begin() requires a WiFiClient instance as the first argument; the single-argument begin(url) form was deprecated/removed in newer core versions.
Fixed param=udevice (not m=udevice) so the query string matches your working browser URL exactly — Domoticz will silently ignore/fail requests with the wrong parameter name.
String(temperature, 1) builds the svalue from your actual sensor reading with 1 decimal place, instead of hardcoding 22.
Checking httpCode and printing http.getString() gives you visibility into whether Domoticz actually accepted the update — useful for debugging idx/passcode issues.

If your Domoticz instance requires HTTPS or basic auth instead of passcode=, that changes http.begin() slightly — happy to adjust if that's your setup.