HC-SR04 module should start with trigger pin LOW

Posted on Sun 11th, February 2018

• #1

Steffen

Just tried out the HC-SR04 module. As soon as require("HC-SR04").connect(...) is called the sensor fires off and logs the distance - without waiting for sensor.trigger().
I suggest to correct the module code to include trig.write(0) as the first line.
• #2

Gordon

Thanks - I've just done that. I'm surprised though - pretty sure the modules I had never did this, but perhaps more recent ones have skipped a pull-down resistor on the inputs.

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