I've got a PIC16F877A in a project of mine and want to be able to measure the power usage of a device that it's driving. I thought that since the 877 has a few ADC's I could use them to sample the Voltage and Current.
Has any one done this before and could offer some pointers or ideas?
The Voltage can be from 0-12v PWM and the current can be up to 15 Amps.
Thanks
DaveC
If you don't need to be very accurate and you need only a single range then it should be very easy to do -- just as you said, periodically take a sample. And if you want to measure current, for simplicity, you probably want to measure the voltage drop over a piece of wire of about 0.1 ohm.
I've once built something similar out of SSI parts (8 bit ADCs, 8051, 32k SRAM, LCD, glue logic) and it wasn't very difficult.
Now, if you need something accurate with auto ranging, then it becomes a lot more complicated.
877"aurgathor" wrote in news: snipped-for-privacy@news.teranews.com:
Thanks.. I've been looking in to using Hall Effect devices. They seem like the go for this sort of thing and seem to be quite stable.
DaveC
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