Arduino Flash Trigger Circuit with Sound Sensor

Nowadays, electronics projects are becoming very popular, especially Arduino based projects are easy to build, because of this the beginners also feel confident.

In this project an Arduino is used to trigger a camera flash, the trigger happens when a sound is detected.

So Arduino Flash Trigger Circuit with Sound Sensor is very useful for high speed photography for example, balloon burst photography or glass breaking shots.

Therefore, this project is simple and powerful for Camera automation projects and sound based triggering systems.

Arduino Coding:

int soundPin = A0;
int flashPin = 7;
int ledPin = 6;
int threshold = 300;

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

void loop()
{
int soundValue = analogRead(soundPin);

if(soundValue > threshold)
{
digitalWrite(ledPin, HIGH);
digitalWrite(flashPin, HIGH);
delay(50);
digitalWrite(flashPin, LOW);
digitalWrite(ledPin, LOW);
delay(200);
}
}

Code Explanation:

• First, the analog pin A0 is defined and this pin reads sound sensor output.
• Then flash pin and LED pin are defined.
• After that a threshold value is set and this value decides when sound is detected.
• In setup function the pin modes are defined.
• Flash pin works as output and LED pin also works as output.
• Initially, flash pin is kept LOW.
• In loop function Arduino reads sound value and then it compares with threshold.
• If sound value is higher then flash triggers.
• At the same time the LED glows.
• After a short delay, everything turns OFF.
• So false triggering is reduced.

Circuit Working:

Parts List:

First, sound occurs near the sensor and then sound sensor converts sound into voltage.

After that Arduino reads this voltage and if voltage crosses set limit then Arduino reacts.

Immediately Arduino activates reed switch and then the camera flash is triggered.

At the same time the LED lights up and so the user can see the flash event.

The resistor R1 ensures proper working of the LED and thus the system works very fast.

Formula with Calculation:

Formula for LED Resistor Calculation:

R = (Vsource − Vled) / Iled

where,

• Vsource is the supply voltage from Arduino which is 5V
• Vled is the forward voltage of the LED which is 2V for red LED.
• Iled is the safe current for the LED which is 10 mA to 20 mA is used.

Vsource is 5V
Vled is 2V
Iled is 10 mA = 0.01 A

R = (5 − 2) / 0.01
R = 3 / 0.01
R = 300 ohm

So a 330 ohm resistor is used for safety in our circuit.

How to Build:

To build a Arduino Flash Trigger Circuit with Sound Sensor follow the below connection steps:

• Assemble all circuit parts like diagram.
• First, connect sound sensor.
• Connect sound sensor VCC to Arduino 5V.
• Connect sound sensor GND to Arduino GND.
• Connect sound sensor OUT to Arduino A0 pin.
• Next, connect reed switch.
• Connect reed switch pin 1 to Arduino digital pin 7.
• Connect reed switch pin 6 to ground.
• Then connect LED.
• Connect Arduino digital pin 6 to R1 330 ohm resistor.
• Connect resistor other end to LED anode.
• Connect LED cathode to ground.
• Finally, connect flash trigger.
• Connect reed switch output pins to flash trigger input.
• Connect flash ground to Arduino ground.

Conclusion:

Finally, this Arduino Flash Trigger Circuit with Sound Sensor is completed.

It is easy to understand and is also with low cost.

Because of simple wiring the beginners can try it.

Moreover, it is very useful for creative photography, with small changes and performance can be improved.

So this project is a good starting point for happy building and experimenting.

References:

Triggering Camera with a Sound Sensor Module