MCP23017-Board: It features address settings via JP5, 6, and 7, implemented as 3-pad solder jumpers.
Two of one pads are currently connected. How should I proceed if I want to change the module address? Do I need to remove the solder blob and then connect the other two pads?
Hi @bible
The address is determined by those jumpers, yes. The address corresponds to the following table:
| A2 (JP7) | A1 (JP6) | A0 (JP5) | Address |
|---|---|---|---|
| 0 | 0 | 0 | 0x20 |
| 0 | 0 | 1 | 0x21 |
| 0 | 1 | 0 | 0x22 |
| 0 | 1 | 1 | 0x23 |
| 1 | 0 | 0 | 0x24 |
| 1 | 0 | 1 | 0x25 |
| 1 | 1 | 0 | 0x26 |
| 1 | 1 | 1 | 0x27 |
They are 3-pad jumpers, so to change the address you need to solder the jumper’s center pad to the 3V3 pad to set that bit to 1, or to the GND pad to set it to 0 (the pad closer to the big chip on board is the one connected to GND). You don’t need to touch a jumper if it’s already bridged the way you want. If a jumper is currently bridged to one side and you need the other, first remove the existing solder blob before bridging the new side.