2. Remote LED Control

Read a 0 or 1 value from PxServ and apply it to an LED. This introduces cloud-to-device data flow through getData().

Level: Beginner · Time: 20 minutes

Parts and wiring

ESP32 DevKit V1
LED and 220–330 Ω resistor

LED side	Connection
Anode, long leg	GPIO 23 through the resistor
Cathode, short leg	GND

PxServ keys

Key	Value	Meaning
`remote-led/command`	`0` / `1`	Requested off / on state
`remote-led/status`	`0` / `1`	State applied by the device

Create remote-led/command with value 0 before starting the device.

Complete sketch


#include <PxServ.h>
 
const char* WIFI_SSID = "your_wifi_ssid";
const char* WIFI_PASSWORD = "your_wifi_password";
const char* PXSERV_API_KEY = "your_pxserv_api_key";
const int LED_PIN = 23;
 
PxServ client(PXSERV_API_KEY);
 
void setup() {
  Serial.begin(115200);
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);
  PxServ::connectWifi(WIFI_SSID, WIFI_PASSWORD);
}
 
void loop() {
  PxServ::Callback result = client.getData("remote-led/command");
 
  if (result.status == 200) {
    bool ledOn = result.data == "1";
    digitalWrite(LED_PIN, ledOn ? HIGH : LOW);
    client.setData("remote-led/status", ledOn ? "1" : "0");
    Serial.println(ledOn ? "LED on" : "LED off");
  } else {
    Serial.print("Command read failed: ");
    Serial.println(result.message);
  }
  delay(2000);
}

Test and troubleshooting

Set the command to 1, then 0. The LED and reported status should follow within two seconds. If the LED does not light, reverse it and confirm the series resistor. If the read fails, compare the exact key and API key with the panel.