Solved an interesting problem last week using an Arduino UNO. We needed to sync two IDS Particle Image Velocimetry (PIV) cameras using a hardware trigger.
https://en.wikipedia.org/wiki/Particle_image_velocimetry
The two cameras were different models and had different connectors. There are many ways to trigger the system depending on what action you want to capture.
https://en.ids-imaging.com/tl_files/downloads/techtip/TechTip_GEV_TriggerCtl_EN.pdf
I could have just connected a function generator to the inputs, but instead chose to use an Arduino UNO for more flexibility.
The hardware trigger inputs to these cameras are opto-isolated, so the output from the UNO can be used directly.
So I mounted an Arduino in a box, powered from the USB, added a couple of LEDS and a pushbutton, and a BNC connector for the output.
The software is fairly straight forward.
/*
CameraTrigger
Last Edit 25 July 2019
by RSC
*/
// constants won't change. They're used here to set pin numbers:
const int PushButtonPin = 5; // the number of the pushbutton pin
const int RedLedPin = 4; // the number of the LED pin
const int TriggerPin = 3; // the number of the trigger pin
const int GreenLedPin = 2; // the number of the LED pin
int buttonState = 0; // variable for reading the pushbutton
// the setup function runs once when you press reset or power the board
void setup() {
// initialize digital pins as inputs/outputs.
pinMode(RedLedPin, OUTPUT);
pinMode(GreenLedPin, OUTPUT);
pinMode(TriggerPin, OUTPUT);
pinMode(PushButtonPin, INPUT);
// initialize serial:
Serial.begin(9600);
}
// the loop function runs over and over again forever
void loop() {
// read the state of the pushbutton value:
buttonState = 0;
digitalWrite(RedLedPin, HIGH);
digitalWrite(GreenLedPin, LOW);
Serial.println("PushButton = Off");
Serial.println("Trigger = Armed");
while (!buttonState){
buttonState = digitalRead(PushButtonPin);
}
delay(200);
Serial.println("PushButton = On");
Serial.println("Trigger = On");
digitalWrite(RedLedPin, LOW);
digitalWrite(GreenLedPin, HIGH);
buttonState = 0;
while(!buttonState){
digitalWrite(TriggerPin, HIGH); // turn the trigger on
delay(50); // wait for X miliseconds
digitalWrite(TriggerPin, LOW); // turn the trigger off
delay(50); // wait for X miliseconds
buttonState = digitalRead(PushButtonPin);
}
delay(1000);
}
