Documentation

// 1-Channel programmable delay relay - fire trigger from Arduino
// Wire Trigger+ to D2, share GND. Module is set to "Delay-On" mode in its menu.

const int triggerPin = 2;

void setup() {
  pinMode(triggerPin, OUTPUT);
  digitalWrite(triggerPin, LOW);
}

void loop() {
  digitalWrite(triggerPin, HIGH);
  delay(150);                     // 150 ms pulse fires the trigger
  digitalWrite(triggerPin, LOW);

  delay(30000);                   // wait 30 seconds before next trigger
}

// ESP32 - fire the time-delay relay from a tiny web page
// Wire Trigger+ to GPIO 5, share GND.

#include <WiFi.h>
#include <WebServer.h>

const char* ssid     = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";
const int   trigPin  = 5;

WebServer server(80);

void fire() {
  digitalWrite(trigPin, HIGH);
  delay(150);
  digitalWrite(trigPin, LOW);
}

void setup() {
  pinMode(trigPin, OUTPUT);
  Serial.begin(115200);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) { delay(300); Serial.print("."); }
  Serial.println(WiFi.localIP());

  server.on("/", []() {
    server.send(200, "text/html", "<a href=\"/fire\">[ FIRE RELAY ]</a>");
  });
  server.on("/fire", []() {
    fire();
    server.send(200, "text/plain", "Triggered.");
  });
  server.begin();
}

void loop() { server.handleClient(); }

#!/usr/bin/env python3
# 1-channel programmable delay relay - fire trigger from Raspberry Pi

import RPi.GPIO as GPIO
import time

TRIG = 17
GPIO.setmode(GPIO.BCM)
GPIO.setup(TRIG, GPIO.OUT, initial=GPIO.LOW)

try:
    while True:
        GPIO.output(TRIG, GPIO.HIGH)
        time.sleep(0.15)
        GPIO.output(TRIG, GPIO.LOW)
        time.sleep(30)
except KeyboardInterrupt:
    GPIO.cleanup()