ARM Cortex M3
User Button (Pulls PA0 to GND when pressed, no current limiting resistor)
Power LED (a pleasant soft green colour)
1 User LED on PC13 (also soft green colour). Lit when PC13 is pulled LOW. Current limiting resistor (510 Ohns) is R15
32khz RTC clock crystal is present
RTC Battery pin is broken out on the header pins. WARNING This is tied to 3v3 via zero Ohm resistor R9
Remove R9 if using an external RTC battery.
AMS1117 3v3 voltage regulator Pins.
20 pin 0.1"(2.54mm) JTag style connector for SWD (pinout is shown in images below).
8 pin 0.1" (socket) header in the middle of the board for 0.96" OLED SWD (pinout is shown in images below).
Two single rows of 20 x 0.1"(2.54mm) pins for GPIO etc one on each of the long edges of the board (pinout is shown in images below).
Unpopulated 6 pin 0.1" header (3 x 2 pins each of 3v3, Gnd, 5V).
24c04 2 wire EEROM 512 byte (4K bits) - on PB6 (I2C_SDA) and PB7 (I2C_SCL) - Address lines A0,A1,A2 and WP are tied to GND
NOTE: This will restrict use of PB6 and PB7 for other purposes.