BMP280 with WeAct Black Pill STM32F411CE

Wiring for the GY-BMP280 pressure + temperature on the WeAct Black Pill STM32F411CE (STM32F411CE, 3.3 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

BMP280 pin	Role	WeAct Black Pill STM32F411CE pin	Notes
VCC	Power	3V3
GND	Ground	G
SCL	I2C clock (SCL)	B6 (PB6)
SDA	I2C data (SDA)	B7 (PB7)
CSB	Not wired to the board	not connected	Chip select. Leave unconnected (pulled HIGH on the board) to use I2C
SDO	Not wired to the board	not connected	Address select: LOW = 0x76, HIGH = 0x77. Most boards default to 0x76

Check before you power it on

Supply: 3.3 V from the 3V3 pin.
I2C uses the board’s default pins B7 (SDA) and B6 (SCL). Most modules include pull-up resistors; if the part is not found, check them and swap-test SDA/SCL.
To make sure it is the real chip, read register 0xD0: a genuine part answers 0x58.

Test code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin();  // SDA = B7, SCL = B6 (the board's default I2C pins)
  Wire.beginTransmission(0x76);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "GY-BMP280 pressure + temperature found at 0x76" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

Arduino board: STMicroelectronics:stm32:GenF4:pnum=BLACKPILL_F411CE,usb=CDCgen,upload_method=dfuMethod. To upload over USB, hold BOOT0, press and release NRST, then release BOOT0 (DFU mode). An ST-LINK on the SWD pins also works.

Questions

Which WeAct Black Pill STM32F411CE pins do I use for the BMP280?

VCC → 3V3, GND → G, SCL → B6 (PB6), SDA → B7 (PB7).

Does the BMP280 work with the WeAct Black Pill STM32F411CE at 3.3 V?

Yes: the BMP280 runs at 3.3 V and the WeAct Black Pill STM32F411CE uses 3.3 V signals, so no level shifting is needed.

What is the I2C address of the BMP280?

0x76 or 0x77. An I2C scan (BoardPilot does it for you) shows which one your module uses.

BoardPilot checks this wiring in 3D as you build it, and finds crossed or missing wires on the real board.

Download BoardPilot

Full WeAct Black Pill STM32F411CE pinout · GY-BMP280 pressure + temperature: all pins and data

The BMP280 on other boards

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