I see, that makes sense. Doing so would put the INA219 in series with the circuit and allow it to measure. It seems simple enough if I have an external power supply, but what if I'm powering it with the same USB connection that powers the Arduino? I currently have the 5V, GND, SDA, and SCL pins of the INA219 connected to their appropriate locations (did a quick test and confirmed), and the GSM is also wired correctly. All I'm having trouble with is the Vin- and Vin+ connections.
I figured I'd simplify things and test the GSM module on its own before also attaching the GPS module. So far, I ran the 5V pin from the Arduino into the Vin+ on the INA219, then ran the Vin- pin to the + rail on the breadboard, which then powers the GSM module as well as the VCC pin on the INA219. Is this correct? The code I have gives me a current value which appropriately spikes when an SMS is sent, but the value seems a bit off (about 200mA when I expect something closer to 2A). It's also giving me a load voltage of 0V which doesn't make sense. I've attached a drawing.
Thank you for your help!
