2.4.12
Function Button (B1/B2)
Pin
Signal Description
1
2
2.4.13
Boot Select (B3)
Boot from Flash Memory when button is pressed.
Chapter 4 – Installation Guide
B1
GND
PB13
Pin
Signal Description
1
2
B2
Pin
Signal Description
1
2
GND
BOOT0
GND
PB14
15