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Phototransistor circuit?

Yeah so what's the minimum circuit to operate phototransistor? (w/ picaxe)

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Phototransistor connected between supply and the input, with a pull-down resistor from the input to ground.

Or you can reverse it and have the phototransistor between the input and ground, with a pull-up resistor between the supply and input.

If I remember correctly at least some PICAXEs have weak internal pull-up resistors which you can enable on certain ports, so you could potentially use these instead. The problem with the internal pull-up resistors is that they're fixed, so you can't adjust the sensitivity of the circuit.