DC power logging, or at least measuring (for solar panel & devices) Answered
I have searched and searched, but I can't seem to find what I need. I want to be able to log power and plot a V-I graph and a P-t graph. I was picturing tapping into an iphone charge cable (for example) and wiring in connections. Here, I could connect the device, so that when i connect the phone via charging usb cable, current runs through the device and is measured, and voltage is read from inlet of the device to gnd.
Do these exist? I'd like to also use it for a solar panel (putting a big wire loop resistor for a load to draw max power) so that I could see where the power tops out, what voltage is yielded when the max current is drawn, etc. It would be nice to be able to plot data points in excel for example.
Any idea? Even if I can't LOG the data, I'd like to be able to read instant power use, not just V and A. I've seen the inline USB meters that do that.
Anything helps! Thank you!