I use the INA219B in this https://www.tindie.com/products/FriedCircuits/usb-tester-oled-backpack-with-display/ . It works really well over i2c.
Thanks for the how to on the ACS712. I tired and it didn’t go so well for AC. So then I tried the ADE7753 and didn’t go well either.
http://www.mobilewill.us/2013/01/smart-outlet-ade7753.html
Haven’t found a great way to monitor 110AC.