Detect 240V with a PIC

[dhouston]

I wasnt gonna use interrupts for this. I need 3 inputs and i dont think this PIC has 3 interrupt pins. I would still have the same problem of needing to reset the interrupt after a certain length of time. Using the cap/resistor method should make it really easy though

Four pins of PortB have InterruptOnChange. You don't need to use interrupts, you merely need to monitor the interrupt flag bits.

[The Master]

Im not sure this whole thing is going to work. I tested it earlier by using a plug with 2 wires connected to the circuit. It seemed to work fine. Now with the smoke machine its not working. Ive had a look at how the smoke machine is wired and it seems that the bulb and motor are shorted out by default and in series with the heater coil. When the coil reaches a set temperature it removes the short which allows the light and motor to be operated.

For some reason when the neutral wire of the smoke machine and the GND of my serial port are connected it shorts the bulb and motor out again. It doesnt seem to be affecting anything but since its 240V being shorted through my laptop im gonna stop here.

I think the best way to go is to use opto isolators. I might not bother doing that for halloween but ill try it out in the future. Another thing i could try is completely re-wiring the smoke machine and putting a PIC inside it. That would let me do some extra advanced stuff like keeping the coil warm (safely) so i never have to wait for it to reheat. I could use the same protocol as my lights.