In this article we connect a BMP388 barometric pressure sensor to a Raspberry Pi Pico running Circuitpython
Sensor Information
The BMP388 is a very small, precise, low power, low noise absolute barometric pressure sensor. It enables accurate altitude tracking and is perfectly suited for drone applications.
By making accurate steering significantly easier, the BMP388 enhances the drone flying experience.
It is compatible for use with other Bosch sensors such as the BMI088 for better performance, robustness and stability. The BMP388 sensor excites with an outstanding design flexibility.
The barometric pressure is usually used to measure barometric pressure and temperature. But besides that, we can also use the sensor to measure the altitude and the relative floor height due to the fact that there is a certain relationship between altitude and barometric pressure.
BMP388 is based on Bosch’s mature Piezo resistive pressure sensor technology featuring high accuracy as well low power consumption and high EMC robustness.
The sensor features an accuracy of about ±8Pa, which is equivalent to about ±0.5m difference in altitude, and an absolute accuracy temperature of ±0.5℃ for a temperature range between 0℃ and 65℃.
FEATURES
- Low power consumption
- Low noise
- High resolution
- Small dimensions
- Best-in-class offset temperature coefficient（-20℃-65℃@700-1100hPa）
SPECIFICATION
- Operating Voltage: 3.3V-5.5V
- Operating Current: 0.5mA
- Operating Range: 300-1250 hPa
- Relative Accuracy: ±8 Pa (equivalent to ±0.50m @700-900hPa, 25℃-40℃)
- Absolute Accuracy: ±50 Pa（0℃-65℃@300-1100hPa）
- Temperature Coefficient Offset: ±0.75 Pa/K（-20℃-65℃@700-1100hPa）
- Absolute Accuracy Temperature: ±0.5℃（@0℃-65℃）
- Operating Temperature: -40℃~80℃ (more accurate in 0℃-65℃)
Parts Required
| Name | Link |
| Pico | Raspberry Pi Pico Development Board |
| BMP388 | BMP388 Atmospheric Pressure Sensor |
| Connecting cables | Aliexpress link |
Schematic/Connection
Black for GND
Red for V+
Blue for SDA
Yellow for SCL
So color coded for ease of use, this layout shows a connection to the module
rp2040 and bmp388
Code Example
I used Thonny for development
The following is based on a library , I copied the adafruit_bmp3xx.mpy library for this device to the lib folder on my Raspberry Pi Pico – https://circuitpython.org/libraries
This is the basic example which comes with the library
[codesyntax lang=”python”]
import time
import board
import adafruit_bmp3xx
import busio
i2c = busio.I2C(scl=board.GP1, sda=board.GP0) # uses board.SCL and board.SDA
# To initialise using the default address:
bmp = adafruit_bmp3xx.BMP3XX_I2C(i2c)
bmp.pressure_oversampling = 8
bmp.temperature_oversampling = 2
while True:
print(
"Pressure: {:6.4f} Temperature: {:5.2f}".format(bmp.pressure, bmp.temperature)
)
time.sleep(1)
[/codesyntax]
Output
Here is what I saw in Thonny REPL window
Pressure: 995.6948 Temperature: 22.52
Pressure: 995.7038 Temperature: 22.47
Pressure: 995.7166 Temperature: 22.40
Pressure: 995.8149 Temperature: 22.70
Pressure: 995.8398 Temperature: 24.51
Pressure: 995.7399 Temperature: 25.07
Links
https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp388-ds001.pdf