Actuator Module

Subscribe, switch, echo state

An actuator node joins the same MQTT broker as the sensor nodes and subscribes to per-output command topics. A command flips a relay driving a solenoid valve (or a pump), then the node publishes the new state back so a dashboard or automation always knows where each output stands. It reuses the WiFi node's connection, naming and OTA plumbing — the difference is outputs instead of inputs.

ARDUINO/GROUU_V1/…/grouu-wrout.ino — MQTT-commanded relay actuation

#define RELAY_ONE    16  // D0
#define RELAY_TWO     5  // D1
#define RELAY_THREE   4  // D2
#define RELAY_FOUR    0  // D3

void turnOnOut1() {
  digitalWrite(RELAY_ONE, HIGH);
  client.publish(MQTT_VALVE_ONE_STATE_TOPIC.c_str(), PAYLOAD_ON);
}
void turnOffOut1() {
  digitalWrite(RELAY_ONE, LOW);
  client.publish(MQTT_VALVE_ONE_STATE_TOPIC.c_str(), PAYLOAD_OFF);
}

Command a valve with <Host>/valve/one/set → ON / OFF; state echoes on <Host>/valve/one. The same system/set/<Host> control topic accepts OTA_ON / REBOOT, exactly like the WiFi node.

Parts for the water router

A minimal, breadboard-friendly build. No priced BOM is published yet — the parts below are what the V1 node uses; the greenhouse set lists the other actuator targets the module is meant to drive.