The INA219 FeatherWing makes power-monitoring problems a thing of the past. Instead of struggling with two multimeters, you can just use the handy INA219B chip on this breakout to both measure both the high side voltage and DC current draw over I2C with 1% precision. Works with any and all Feathers! Communicates over I2C so its super-simple to use, you can even change the I2C address to have up to 4 of these Wings on one Feather.