ARDUINO sound activated flash or camera trigger



This tutorial will show you how to build a simple circuit to connect to a ARDUINO micro controller that will detect sound and trigger your camera or flash for high speed photography. This is easy to assemble and only cost a few $$$ for the parts…




The picture above is the schematic for the circuit you will need to build… if you click on the picture it will enlarge so you can see it better….

The parts you will need:
220Ω resistor X 1

10KΩ resistor X 2

100KΩ resistor X 1

1MΩ resistor X 1

0.1µf capacitor X 2

1N4001 (or allmost any diode will work) X 1

MPS2222A ( or any similar transistor like 2N2222 will work) X 1

optocoupler ( any 4 pin type should work, I used a Sharp PC817) X 1

Microphone X 1

any ARDUINO board X 1





copy and paste the following code into your ARDUINO IDE…

int flash = 9;   //flash or camera trigger pin
int mic;
int lvl = 0;
int trig;
void setup() {
pinMode(flash, OUTPUT);
void loop() {
if (lvl == 0)
Serial.println(“What Sound Trigger LVL do you want? “);
lvl = 9000;   //sets trigger lvl high so it wont trigger till you enter a value
if (Serial.available())
lvl = Serial.parseInt();
lvl = constrain(lvl, 25, 9000);   //stops you from setting sound detection lvl to low and cause continuous
Serial.print(“Sound Trigger LVL is “);   //triggering, you can change the 25 to a lower # but don’t go under 15
Serial.println(“What Sound Trigger LVL do you want? “);
trig = 0;
mic = analogRead(A0);
if (mic >= lvl)
digitalWrite(flash, HIGH);
digitalWrite(flash, LOW);
trig = trig + 1;
Serial.print(“Flash has been Triggered “);
Serial.println(” Times!”);
delay(1000);   //delay so your camera or flash only triggers one time from a sound


After you get the code loaded onto the arduino power it up then plug it into your flash or camera. It wont hurt the camera or flash to have it connected when you power up the arduino but it will trigger it one or two times when its first starting up…

Next open up your serial monitor, you can use the one on your computer or if you have a android smart phone & a USB OTG cable you can down load a free serial monitor from the play store.. Just follow the instructions on the serial monitor and your good to go, if you have any problems or questions leave a comment on our Facebook Page and ill try to help you out…