4-20ma or 0-10vdc

[gadget-evilusions]

Recently I have come upon a few projects where being able to input and output either a 4-20ma signal, or a 0-10vdc, would be great. I would like to control some servo valves which can provide exact position in a feed back pneumatic cylinder. Is there a way to be able to do this with a prop-1? If not, another board or combination?

Thanks,

[JonnyMac]

I have seen 4-20 circuits that take an analog in through an opamp which drives a transistor -- that transistor is what controls current through the loop. If the current output is not too heavy you could "program" (via feedback resistor) the opamp circuit to be a 2x amplifier. Then you could do PWM into an RC circuit and this would get doubled by the opamp.