I'm trying to use an HC-SR04 Ultrasonic sensor through arduino with Pure Data using Pduino and Standard Firmata. Pduino works perfectly and I am able to get data from many other sensors. This particular sensor is slightly different because it needs me to send a pulse of length 30 micro seconds at a time interval of more than 60 milliseconds to the trigger pin of the sensor, which triggers the ultrasonic waves from the transmitter. The receiver of the sensor measures the ultrasonic waves as they bounce back after reflecting from an external object to measure the distance.
My problem is that I am trying to figure out how to give a 30 microsecond pulse as an output from Pd, which leads me to ask, how long does a 'Bang' last? Is there another way to set up a pulsing mechanism where I can control the time interval of the pulse? Something like the pulseIn() function in Arduino IDE?