STM32F407VET6 Microcontroller Board

I'm going to be use this “STM32F407VET6 ARM Mini Version Core Board Cortex-M4 STM32 Minimum System Board”, available from Banggood and from Taobao.com as well. Prices range about US$15.00. (Note that the designation on the photo is wrong; I'm pretty sure it's a 25MHz crystal, not 8MHz for the CPU clock.)

This board uses the 100 pin package, so plenty of GPIO pins and peripherals available. It's also relatively compact, as well.

Here's a table to try to enumerate the GPIO pin usage, trying to capture some I/O signals that are connected to on-board peripheral expansion and not available for general use.

Connector GPIO Pin Function
PC8 On-Board MicroSD card pin 7 with 10KΩ pull-up
PC9 On-Board MicroSD card pin 8 with 10KΩ pull-up
PC10 On-Board MicroSD card pin 1 with 10KΩ pull-up
PC11 On-Board MicroSD card pin 2 with 10KΩ pull-up
PC12 On-Board MicroSD card pin 5 with 10KΩ pull-up
PD2 On-Board MicroSD card pin 3 with 10KΩ pull-up
P1_1 GND
P1_2 GND
P1_3 VBAT
P1_4 VCC_3V3
P1_5 VIN_5V
P1_6 VIN_5V
P1_7 PE0
P1_8 PE1
P1_9 PE2
P1_10 PE3
P1_11 PE4
P1_12 PE5
P1_13 PE6
P1_14 PC13
P1_15 PC14 RTC XTAL
P1_16 PC15 RTC XTAL
P1_17 PC0
P1_18 PC1
P1_19 PC2
P1_20 PC3
P1_21 PA0 UART4-TX (reserved for TX to optional ESP32)
P1_22 PA2 UART2-TX (unused?)
P1_23 PA1 UART4-RX (reserved for RX from optional ESP32)
P1_24 PA3 UART2-RX TX to GPIB I/F
P1_25 PA4 SPI1 NSS
P1_26 PA5 SPI1 SCK
P1_27 PA6 SPI1 MISO (don't need for LCD)
P1_28 PA7 SPI1 MOSI (for LCD display)
P1_29 PC4
P1_30 PC5
P1_31 PB0
P1_32 PB1
P1_33 PB2 BOOT1 switch
P1_34 PE7
P1_35 PE8
P1_36 PE9
P2_1 PE11
P2_2 PE10
P2_3 PE13
P2_4 PE12
P2_5 PE15
P2_6 PE14
P2_7 PB11
P2_8 PB10
P2_9 PB13 SPI2 SCK
P2_10 PB12 SPI2 NSS
P2_11 PB15 SPI2 MOSI (7-segment SPI LED?)
P2_12 PB14 SPI2 MISO
P2_13 PD9 UART3-RX RX from GPIB I/F
P2_14 PD8 UART3-TX (unused?)
P2_15 PD11
P2_16 PD10
P2_17 PD13
P2_18 PD12
P2_19 PD15
P2_20 PD14
P3_1 PC8
P3_2 PC6
P3_3 PC9
P3_4 PC7
P3_5 PA9 UART1 TX “console”
P3-6 PA8 On-Board MicroSD card present switch with 10KΩ pull-down
P3-7 PA11 On-Board USB D-
P3_8 PA10 UART1 RX “console”
P3_9 PA13 SWD - SWDIO
P3-10 PA12 On-Board USB D+
P3_11 PA15 SPI3 NSS
P3_12 PA14 SWD - SWCLK
P3_13 PC11
P3_14 PC10
P3_15 PC12 UART5-TX (reserved for generic IR/IrDA?) See example
P3_16 PD0
P3_17 PD1
P3_18 PD2 UART5-RX (reserved for generic IR/IrDA?)
P3_19 PD3
P3_20 PD4
P3_21 PD5
P3_22 PD6
P3_23 PD7
P3_24 PB3 SPI3 SCK (reserved as spare?)
P3_25 PB4 SPI3 MISO (reserved as spare?)
P3_26 PB5 SPI3 MOSI (reserved as spare?)
P3_27 PB6
P3-28 PB7 On-Board AT24C08 SDA with 4.7KΩ pull-up
P3-29 PB6 On-Board AT24C08 SCL with 4.7KΩ pull-up
P3-30 PB9 On-Board LED tied to +3.3v
P3_31 GND
P3_32 GND
P3_33 VCC_3V3
P3_34 VCC_3V3
P3_35 GND
P3_36 GND