INA226 current sensor
Measuring current in a design used to be a bit tricky. But with modern semiconductors this is no more effort than a tiny module with an I2C bus. It only needs three resistors and two capacitors. I used this IC in the
USB Power Monitor. (Scroll down for Cal register calculator.) 
The trick is done with the INA226 by Texas instruments. The chip can be obtained as free sample.
Two tiny PCBs.
The only challenging part is the very small IC package. Here a microscope pic of the PCB. This is without tining.
The trick is done with the INA226 by Texas instruments. The chip can be obtained as free sample.
Two tiny PCBs.
The only challenging part is the very small IC package. Here a microscope pic of the PCB. This is without tining.