Green Pill
STM32L431CBT6
Board
| Name | Green Pill |
| Part | STM32核心板 (Core board) |
| Brand | Unknown |
| Origin | China |
Microcontroller
| Part | STM32L431CBT6 |
| Manufacturer | ST-Microelectronics |
| Core | Arm Cortex-M4 |
| Max. Clock Speed | 80MHz |
| Package | LQFP 48 pins |
Internal memories
| FLASH | 256KiB |
| SRAM | 64KiB |
Oscillators
| HSI | 16MHz |
| LSI | 40kHz |
| HSE | 8MHz |
| LSE | 32.768kHz |
Power
| Sources | Any +3.3V pin (+3.3V) Any +5V pin (+5V) USB connector (+5V) |
| VDDA pin | No |
| VSSA pin | No |
| VREF- pin | No |
| VREF+ pin | No |
| Backup battery | Pin |
Regulator
| Manufacturer | Shanghai TX Electronics Sci-Tech Co., Ltd |
| Part | TX6211B (DE=A1D) |
| Package | SOT23-5 5 pins |
| Input | +3.6V to +5.5V |
| Output | +3.3V @ 300mA |
| Datasheet | TX6211B.pdf |
PCB
| Color | Green |
| Size (w x l) | 24mm x 60mm |
| Mounting | Breadboard and 4x mounting hole (M3) |
Remarks
- Warning: The +5V pins on this board are directly connected to the +5V pin of the USB connector. There is no protection in place. Do not power this board through USB and an external power supply at the same time.
Pictures
Resources
Inputs
Connectors
Devices
Inputs & outputs
Reset button
| Name | RESET |
| Reference | - |
| Type | Button |
| Connected to | NRST |
| Mode | Active low |
BOOT0 jumper
| Name | B0 |
| Reference | - |
| Type | 2-way jumper |
| Connected to | BOOT0 |
| Mode | N.A. |
BOOT1 jumper
| Name | B1 |
| Reference | - |
| Type | 2-way jumper |
| Connected to | PB2 |
| Mode | N.A. |
Power LED
| Name | POW-LED |
| Reference | LED3 |
| Type | LED |
| Connected to | +3.3V rail |
| Mode | N.A. |
User LED
| Name | RUN-LED |
| Reference | LED1 |
| Type | LED |
| Connected to | PA0 |
| Mode | Sink |
Connectors & headers
Header 1 properties
| Name | Unknown |
| Reference | None |
| Type | Pin header (2.54mm, 20x1, male) |
Header 1 pins
| # | Name | Function | Connected to |
|---|---|---|---|
| 1 | VBAT | - | VBAT |
| 2 | PC13 | - | PC13 |
| 3 | PC14 | - | PC14 |
| 4 | PC15 | - | PC15 |
| 5 | RST | - | RST |
| 6 | PA0 | - | PA0 |
| 7 | PA1 | - | PA1 |
| 8 | PA2 | - | PA2 |
| 9 | PA3 | - | PA3 |
| 10 | PA4 | - | PA4 |
| 11 | PA5 | - | PA5 |
| 12 | PA6 | - | PA6 |
| 13 | PA7 | - | PA7 |
| 14 | PB0 | - | PB0 |
| 15 | PB1 | - | PB1 |
| 16 | PB2 | - | PB2 |
| 17 | PB10 | - | PB10 |
| 18 | PB11 | - | PB11 |
| 19 | GND | - | Ground plane |
| 20 | +5V | - | +5V rail |
Header 2 properties
| Name | Unknown |
| Reference | None |
| Type | Pin header (2.54mm, 20x1, male) |
Header 2 pins
| # | Name | Function | Connected to |
|---|---|---|---|
| 1 | GND | - | Ground plane |
| 2 | PB9 | - | PB9 |
| 3 | PB8 | - | PB8 |
| 4 | PB7 | - | PB7 |
| 5 | PB6 | - | PB6 |
| 6 | PB5 | - | PB5 |
| 7 | PB4 | - | PB4 |
| 8 | PB3 | - | PB3 |
| 9 | PA15 | - | PA15 |
| 10 | PA14 | - | PA14 |
| 11 | PA13 | - | PA13 |
| 12 | PA12 | - | PA12 |
| 13 | PA11 | - | PA11 |
| 14 | PA10 | - | PA10 |
| 15 | PA9 | - | PA9 |
| 16 | PA8 | - | PA8 |
| 17 | PB15 | - | PB15 |
| 18 | PB14 | - | PB14 |
| 19 | PB13 | - | PB13 |
| 20 | PB12 | - | PB12 |
USB connector properties
| Name | USB2.0 |
| Reference | USB2 |
| Type | USB Micro |
USB connector pins
| # | Name | Function | Connected to |
|---|---|---|---|
| 1 | - | VCC | +5V rail |
| 2 | - | D- | PA11 via 22Ω (R7) |
| 3 | - | D+ | PA12 via 22Ω (R9) |
| 4 | - | ID | N.C. |
| 5 | - | GND | Ground plane |
SWD header properties
| Name | Unknown |
| Reference | J1 |
| Type | Pin header (2.54mm, 4x1, male) |
SWD header pins
| # | Name | Function | Connected to |
|---|---|---|---|
| 1 | GND | GND | Ground plane |
| 2 | SWD | SWDIO | PA13 |
| 3 | SWC | SWCLK | PA14 |
| 4 | 3V3 | VCC | +3.3V rail |
Devices
24C02N properties
| Name | 24C02 |
| Reference | U3 |
| Manufacturer | Unknown |
| Part | 24C02N |
| Marking | 24C02N |
| Datasheet | Unavailable |
| Package | SOIC 8 pins |
| Description | 256B I2C EEPROM |
24C02N pins
| # | Name | Function | Connected to |
|---|---|---|---|
| 1 | - | A0 | Ground plane |
| 2 | - | A1 | Ground plane |
| 3 | - | A2 | Ground plane |
| 4 | - | GND | Ground plane |
| 5 | - | SDA | PB7 pulled up by 4.7kΩ resistor |
| 6 | - | SCL | PB6 |
| 7 | - | WP | N.C. |
| 8 | - | VCC | +3.3V rail |