This is the latest in a long line of excellent barometric pressure sensors from Bosch. Why we remember the BMP series back when it was a wee BMP085 – it seems like just about every year there’s been an improvement: the BMP180, BMP280 – still a very popular chip! And the BMP388.
With each generation comes an improvement in the pressure accuracy and precision. Earth’s ambient barometric pressure changes with altitude – because air gets thinner the higher you go. There’s a simple calculation that can be used to determine relative altitude changes and, if you know the sea level pressure (which usually doesn’t vary much) you can use that to determine the absolute altitude. The better and more accurate your pressure readings, the better your altitude calculation output.
Historically, these sensors could give you about 1 or 2 meter accuracy in altitude detection. This new version has a relative accuracy of 3 Pascals, which translates to about 25 cm. All in a tiny 2mm x 2mm package with both I2C and SPI interfaces. This makes them great for use with drones: paired with a GPS and IMU, you’ll get great absolute-positioning and improve altitude stability.
Since barometric pressure is also used to perform weather predictions, this sensor is also excellent for any sort of ambient weather detection – just like the ‘analog’ barometers we had when I was growing up. Low pressure means air is moving in, bringing clouds, storms and wind; high pressure means air is moving out, so there will be fair weather without clouds. In addition to pressure, you also get temperature sensing, which is used to calibrate the pressure reading, but can also aid in environmental sensing.
Thankfully, this chip is pin compatible with the BMP388, so we were easily able to put together a demo to test this out. We updated our GitHub repo for the BMP3XX series to add support for the BMP390 as well, so you can use any Arduino-compatible to talk to this fancy new chip. Bosch also has a C API that we found easy to integrate into any existing framework – you just provide the underlying I2C/SPI calls.
Digi-Key has some in stock right now at https://www.digikey.com/short/zn2pfn – place and order today and you can start integrating these new chips to upgrade your sensor platform tomorrow!
See more from the manufacturer video below