Expansion Socket

The expansion port of each ECU is a 26-pin socket.

By default, all ECUs share a common hardware peripherals configuration, so that programming is easier and so that misconfigurations are less likely to happen.

For example, PA1 is always configured as an ADC. In the chassis expansion, it is connected to the steering wheel potentiometer. In the powertrain expansion, it is connected to the brake potentiometer. Different sensors and circuits, but same peripherals configuration in the ECU. This also means that binary inputs (such as the side-brake) are treated as ADC input instead of GPIO input.

By default, pins are configured as shown below.

PA1

PA2

PA3

PA4

PA5

PA6

PA7

PB0

PB1

PB2

PB10

PB11

PB12

PB13

PB14

PB15

PA8

ADC

QSPI

ADC

QSPI

GPIO

SPI2

GPIO

../_images/ecu_socket_pinout.png — ECUs expansion port connections.

The pinout is the same for all ECUs. They are oriented differently depending on their location on the board. Refer to the following KiCAD screenshots to ensure that you have the correct orientation.