BLACK-PILL-HUB

Features

• Carrier for the STM32 Black Pill Board
  • STM32F401/411 CPU
• I2C Hub - PCA9544A
  • 4-channel
  • Independent 3.3V/5V power for each channel
• Separate interrupts for each channel
• GVS connections for Blue Pill pins
• Reset switch

Black Pill Module

Not pin compatible with Blue Pill due to power pin locations

Connectors

J1 - 5V power

• DC jack
• 5V
• Center positive

J4 - 5V Power

• 5mm terminal block

J7 - I2C

• The I2C interface that goes to the I2C hub part

1. SCL (PB6)
2. SDA (PB7)
3. 3.3V
4. GND

P1 - 5V

• 2x4 header with 5V from H2 (Rev 4 card)

P2 - Vbattery

• Battery power to the Blue Pill board

1. GND
2. Vbat

P3 - FTDI connector (Rev X1-X3)

• To cable to FTDI wires swap pins 4 and 5 in cable
• FTDI card jumper has to be set to 3.3V since STM32 has 3.3V signal levels

1. GND
2. N/C
3. VCC (to H8 pin 2)
4. TX (to Blue Pill RX) (PA10 pin on STM32)
5. RX (to Blue Pill Tx) (PA9 pin on STM32)
6. RESET*

P3 - FTDI Module (Rev 4 or higher)

• Cheap FT232 module pinout

P4, P5, P6, P7 - I2C Interfaces #0-#3

1. INT*
2. SCL
3. SDA
4. VCC
5. GND

P8 - SPI

1. PA6 (MISO)
2. 3.3V
3. PA5 (SCK)
4. PA7 (MOSI)
5. RES
6. GND

P11/P12 - GVS Connector

• Ground, Power, Signal pins

1. n/c
2. PC13
3. PC14
4. PC15
5. PA0
6. PA1
7. PA2
8. PA3
9. PA4
10. PA5/SCK1
11. PA6/MISO1
12. PA7/MOSI1
13. PB0
14. PB1
15. PB10
16. PB11

P12/P13 - GVS Connector

• Ground, Power, Signal pins

1. n/c
2. PB9
3. I2C_INT (PB8)
4. I2C_SDA1 (PB7)
5. I2C_SCL (PB6)
6. PB5
7. PB4
8. PB3
9. PA15
10. PA12
11. PA11
12. RX
13. TX
14. PA8
15. PB15
16. PB14
17. PB13
18. PB12

Headers

H1 - 3.3V (Rev X1-X3)

• Install to power 3.3V from regulator

H1 - 3.3V source select

• 1-2 power from 5V to 3.3V regulator
• 2-3 Power from Blue Pill board 3.3V regulator

H2 - 5V Jumper (Rev X1-X3)

• Install to connect J4 and J1 5V

H2 - 5V Power Source (Rev 4 or higher)

• T-shaped header
• Up - Power 5V from BluePill Hub USB power
• Left - Power 5V from DC Jack
• Down - Power 5V from FTDI 5V

H3, H4, H5, H6 - I2C Power

• Select the power to the I2C interface
• Install in one of the two positions to power external I2C interface from the board
• Remove if power comes in from external I2C interface

1. 3.3V
2. 5V

H7 - 3.3V from Blue Pill module 3.3V regulator

• Install = power on-board 3.3V circuitry from regulator on Blue Pill module
  • H8 should not be installed if H7 is installed

H8 - Power from FTDI

• 1-2 = 3.3V from FTDI (don't ever do this)
• 2-3 = 5V from FTDI (probably don't do this)
• H7 should not be installed if H8 is installed

H9 - Hub Chip Address

• Select the address of the PCA9544A I2C hub

Switches

SW1 - Reset Switch

• Press to reset Blue Pill board

Schematic

• Schematic - Rev 3 Board
• Schematic - Rev 4 Board

Testing

• Arduino Based Test Station

Programming

• ST-LINK V2
• FLASHER-STM32 - STM32 Flash loader demonstrator (UM0462)
• From AN3155

Rev 1 Board

Assembly Sheet

• Blue Pill Hub Assembly Sheet Rev 4
• Blue Pill Hub Assembly Sheet - Rev 3