Matrix user forums

The objective of my flowchart is to send out a single pulse when the momentry switch is pressed. The pulse duty is adjustable using the potentiometer connected to pin 5 of the 12F683 chip.

The simulation works great and the burning to chip is all fine as far as I can make out. However, when I build the circuit on my prototype board, the led keeps triggering and I cannot figure out why. I did measure on pin 6 (trigger pin) that there is a voltage of about 200 to 250mV regardless what state the switch is in.

I'm sure somebody can spot what I have done wrong and point it out. I have attached my flow chart and schematic.

Once again, many thanks guys.........John

Pin 6 is floating when the switch is not pressed, it is probably best to connect it to 0V with a 10K resistor. That makes sure the signal is well defined and less susceptible to electronic noise.

Thanks kersing, seems to have done the trick.

Appreciate your help a lot

Thanks..............John