How to get A/D Value for Current.

NewSpace · Joined: 23 Sep 2003 Posts: 12 Location: South KOREA

Hello?

nice to meet you? and so sorry I'm poor english please understand to me.

I wanna know DC Motor's current.
so how to get DC Motor's current?

Before I try get the volt value ... on PIC A/D port

But how to...?

If you can give to me about sample source and SCH file...
Please help me...

Thank you~~~!
_________________
Hello~?

This is South KOREA
My name is Sanghyouk Kim But Call me Nick
Sorry I'm poor English

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley

You probably can get away with low-side current sensor. Put a resistor from the low side of the motor (or an H-bridge, if you have it) to ground. The V=IR would probably be small, but you can amplify it with a non-inverting op-amp. Connect the output of theopamp to the PIC's A/D and measure the voltage, which will be V=AIR, where A is the gain of your op-amp.

Nick · Guest

Thank you..

Can U teach me about best op-amp?

kender · Joined: 09 Aug 2004 Posts: 768 Location: Silicon Valley