I have a device which has 2 5v outputs and under certain conditions one falls to 0. I wish to detect this situation and take further action. Can I do this with Arduino?
I have looked at inverting the situation using CMOS logic NAND gate but the voltages are too low.
it might be easier to do this with some transistors and not bother with software.
Strange concept.If you do not want to bother with software, you do not use a microcontroller such as an Arduino.
OP said the voltages were too low for CMOS to sense. If it's too low for CMOS to sense it's going to be too low for an Arduino to sense.
I have managed to invert the signal using 2 transistors and now have an output of 5v but not enough current to operate a 5v relay. Any suggestions?