I have created a solar cell datalogger using an Arduino, a light intensity sensor module, SD card module, INA219 current/voltage sensor, and a temperature sensor. Coding all of this is not the issue, but I just want to confirm as to if the attached circuit makes sense and will work (i.e. things won't get damaged). The temperature sensor, light intensity sensor, and SD card module are separate from the solar cell and I have confirmed that these sensors work 100% using the wiring shown in the attachment. I used a MOSFET as a switch to open and close the solar cell circuit so that I can measure the short-circuit current and open-circuit voltage of the solar cell throughout the day (I do not need to know how much current is drawn from a load so I do not have a load attached). My main concern is the wiring of the INA219 sensor and if it is correct. Any help, guidance, or concerns would be appreciated. The solar cell I am using to test the circuit is rated at 5.5V 170mA 1W, but the actual solar cell I will be using will have a much lower voltage and current (i.e. dye-sensitised solar cells). Let me know if any additional information is required to explain the circuit further.
I noticed that you do not have a shunt resistor across the Vin+ and Vin- inputs of the INA219. The A/D is measuring the differential voltage across this resistor. You don't have a current path without it, so you'll always have an open circuit.
Also, they recommend adding an RC filter across the inputs if you look in the applications example in the spec.