How to connect to STM expansion connector?

The main board of STM modules 5″,7″,10″ and 12″ has one 1.27mm, 40-pin expansion pin socket which is labeled as
“EXPANSION CONNECTOR”.

It provides direct access to below GPIOs of MCU, which make it possible to easily extend a
daughterboard for a specific application.
• 2 x I2C
• 1 x UART
• 1 x USART
• 1 x SPI
• 1 x USB
• 7 x PWMs
• 1 x DAC(Digital-to-analog)
• 2 x ADCs (Analog-to-digital)

Each of the GPIO pins can be configured by software as output (push-pull or open-drain,
with or without pull-up or pull-down), as input (floating, with or without pull-up or pulldown) or as peripheral alternate function. Most of the GPIO pins are shared with digital or
analog alternate functions.

Please refer to the datasheet of MCU for more details.

To connect to 5″ expansion connector please use matching connector:

P/N CH51402M100-0P

To connect to 7″,10″ or 12″ expansion connector please use matching connector:

P/N CBC1402M100-2P

Expansion connector on 5" STM boards

5" STM expansion connector scheme

Expansion connector on 7" and 10" STM boards

7" and 10" STM expansion connector scheme