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BMP280

Pinout

Table of Contents

Overview

  • Name: BMP280
  • Description:

Library for Bosch BMP280 Digital pressure sensor hardware SPI or I2C.

  • Developed on

    1. Raspberry pi PICO RP2040
    2. SDK C++ compiler, arm-none-eabi-g++ (15:10.3)
    3. CMAKE , VScode

  • Supports sensors features:

  1. Read pressure data
  2. Read temperature data
  3. Tested on SPI interface and I2C interface, Interface is selected by user constructor overload(see examples)
  4. Oversampling settings , standby times, Filter settings and can be set thru API.
  5. Normal mode, sleep mode and forced mode supported.
  6. This supports the BMP280 sensor fully only. The humidity functionality of the BME280 is not tested or supported.
  7. 3 examples:main.cpp files 2 for SPI and 1 for I2C, pick the one you want in CMakeLists.txt, add_executable section.
  8. Chip ID should be 0x56-0X58 for BMP280, 0x60 BME280.

Default settings

BMP280 Setting Default Enumeration
Oversampling Temperature Sampling_X16 (5)
Oversampling Pressure Sampling X2 (2)
Standby Duration StandBy_MS_1 (0)
Filter Filter_Off (0)
Power mode Normal (2)

Connections

The Sensor uses SPI or I2C for communication with the pico.

SPI Connections

The BMP280 can be connected to the Raspberry Pi Pico using SPI. The following table shows the pin connections between the BMP280 and the Raspberry Pi Pico spi0. The BMP280 is a 3.3V device and the Pico is also a 3.3V device. The BMP280 has a CSB pin which can be connected to any GPIO pin on the Pico. The CSB pin is active low, so it should be pulled high when not in use. Can be set up for any SPI interface and bus speed.

BMP280 Pin Function Pico GPIO Notes
CSB Chip Select (CS) GPIO 17 Active Low pick any GPIO
SDA MOSI (Data In) GPIO 19 Master Out Slave In
SCL SCK (Clock) GPIO 18 SPI Clock
SDO MISO (Data Out) GPIO 16 Master In Slave Out

I2C Connections

The BMP280 can be connected to the Raspberry Pi Pico using I2C. The following table shows the pin connections between the BMP280 and the Raspberry Pi Pico I2c1. The BMP280 is a 3.3V device and the Pico is also a 3.3V device. I2C error timeout and baudrate can be adjusted. The BMP280 has a CSB pin which can be connected to any GPIO pin on the Pico. The CSB pin is active low, so it should be pulled high when not in use. The I2C address of the BMP280 is 0x76 or 0x77 depending on the SDO pin connection.

BMP280 Pin Function Pico GPIO Notes
SDA Data GPIO 18 I2C DATA
SCL Clock GPIO 19 I2C Clock
CSB Chip Select n/a set high
SDO MISO n/a used to select I2C address, If SDO is high then the I2C address is 0x77. If SDO is low the I2C address is 0x76.

Output

Data is outputted (eg to a PC) via a USB.

op