1. Make sure you enable i2c interface, refer to How to enable I2C
2. Please check if the pogp pin of [[X1202 ]] or other ups shield [[X1200]] /[[X1201]] is in close contact with the pad position of PI 5. There won't be any other problems, it's this poor contact that's causing it.
[[File:X1002-no-found-i2c.jpg]]