The 20-pin standard extension headers that are always found
on Xplained Pro MCU boards are named and located at fixed positions around the board edge.
Extension header EXT1, EXT2, and EXT3 are reserved for standard Xplained Pro extension
headers The tables below shows standard header placement and which connectors are commonly
found on the different board sizes. Additional 20-pin extension headers can be placed at
other locations on the board.
Table 1. Standard Header Placement
| Header |
Placement |
| PWR |
Referenced to the upper right corner of the PCB |
| EXT1 |
Referenced to the upper right corner of the PCB |
| EXT2 |
Referenced to the upper right corner of the PCB (EXT2 is
never implemented on small boards) |
| EXT3 |
Referenced to the lower right corner of the PCB |
Table 2. Xplained Pro Board Sizes and Standard Headers
| Board Size |
Standard Connectors |
| Small |
PWR, EXT1, and EXT3 |
| Medium |
PWR, EXT1, EXT2, and EXT3 |
| Large |
PWR, EXT1, EXT2, and EXT3 |