Finally getting around to making a proper Picaxe programming board after years of kludging things together.
I would like to include a capability to sense when a connected computer is trying to program a chip, and automatically turn on 5V to power the chip, and then turn the power off when the chip is programmed. I'm hoping to use a 5V 20ma relay driven by a mosfet for the switch, but I don't understand the programming cable and protocols well enough to know if this is possible and what voltage levels I should be trying to sense. I'd prefer to drive the mosfet directly from the AXE cable, but I could use an 08M2 for sensing and logic for the power control if needed.
The attached is a preliminary layout for the PCB that will carry the ZIF socket, plus power and data plugs but minus the sensing circuit.
Advice on how to make the power control sensor work would be appreciated.
I would like to include a capability to sense when a connected computer is trying to program a chip, and automatically turn on 5V to power the chip, and then turn the power off when the chip is programmed. I'm hoping to use a 5V 20ma relay driven by a mosfet for the switch, but I don't understand the programming cable and protocols well enough to know if this is possible and what voltage levels I should be trying to sense. I'd prefer to drive the mosfet directly from the AXE cable, but I could use an 08M2 for sensing and logic for the power control if needed.
The attached is a preliminary layout for the PCB that will carry the ZIF socket, plus power and data plugs but minus the sensing circuit.
Advice on how to make the power control sensor work would be appreciated.