J
jim
- Jan 1, 1970
- 0
I want to build a little device that will measure current flow to/from my
deep cycle batteries. I want this use a microcontroller to provide data
collection etc. The currents involved will be 0-30amps, either direction (
load and charging).
I seems to me that the 50mV from the shunt is far too low a value to
measure directly with the AVR's ADC, not to mention the problem of the
"negative voltage" on the shunt with the battery is being recharged (and
yes, I do want to measure charge current as well.
The entire device will be powered by the battery system itself, using 7805
(or some similar 5V regulator) to supply Vcc for the AVR.
I'm guessing I'll need to use some sort of opamp circuit to scale the
-50mV-to-+50mV raw input to something like 0-2.56 volts to be read by the
ADC.
My question is... how do I do this.. I'm more of a digital type so I'm
looking for advice on this analog project.
thanks
- jim
deep cycle batteries. I want this use a microcontroller to provide data
collection etc. The currents involved will be 0-30amps, either direction (
load and charging).
I seems to me that the 50mV from the shunt is far too low a value to
measure directly with the AVR's ADC, not to mention the problem of the
"negative voltage" on the shunt with the battery is being recharged (and
yes, I do want to measure charge current as well.
The entire device will be powered by the battery system itself, using 7805
(or some similar 5V regulator) to supply Vcc for the AVR.
I'm guessing I'll need to use some sort of opamp circuit to scale the
-50mV-to-+50mV raw input to something like 0-2.56 volts to be read by the
ADC.
My question is... how do I do this.. I'm more of a digital type so I'm
looking for advice on this analog project.
thanks
- jim