I2C expander used in relay boards. You likely must have this configured. By defoult one relay board has 2 or 3 PCA9685 installed.
pca9685:
- id: pca1
address: 0x20
- id: pca2
address: 0x21
pca9685:
- id: pca1
address: 0x20
- id: pca2
address: 0x21
- id: pca2
address: 0x22