Review on Tolako Arduino Indicator Channel Official by Javarie Brumfield

. It works with the Arduino Uno BUT it doesn't explain the trigger pins and for that reason I only gave it 3 stars. To make it work I had to tie the S and + input pins together, apply +5V to the two pins and ground to the - input pin. To get stable +5V with enough current I used pin 6 of analog PWM output. I added the following block of code to the void loop() section of my sketch: analogWrite(shutterRelayPin, 255);delay(delayPeriodTrip);analogWrite(shutterRelayPin, 0);delay(delayPeriodClose);Your code may be different. For example, you might find that a digital PIN and digital entry works for you. In any case, the delays allow the circuit to stabilize and resolve the transients between tripping and closing. An analog write command of 255 sets the voltage on pin 6 to +5V, and an analog write command of 0 turns it off. You can hear the relay turn on and off and use a multimeter on the output tips to make sure it's working. The relays need a diode on the input coil to prevent the jump spike from destroying your Arduino when the relay is turned off. This little circuit has that, plus a handy LED to show triggered status and circuitry to match the current to the Arduino Uno, and for those reasons it's better than just a relay.