BMP388 Pressure & Temperature Sensor - Continuous measurement using FIFO

In this example we will be showing how to use the built-in FIFO buffer on the BMP388 sensor to store measurements and print them out when needed.

Setting Up

Initialization is done in a similar way as in the previous examples, with the main difference being that we initialize the FIFO with a set number of measurements which will be saved into the FIFO:

from machine import Pin, I2C
from bmp388 import BMP388
from bmp388_constants import TIME_STANDBY_1280MS, FIFO_DATA_READY, FIFO_CONFIG_ERROR
import time

NO_OF_MEASUREMENTS = 10

# If you aren't using the Qwiic connector, manually enter your I2C pins
# i2c = I2C(0, scl=Pin(22), sda=Pin(21))
# bmp388 = BMP388(i2c)

# Initialize sensor over Qwiic
bmp388 = BMP388()

# Set sea level pressure for accurate altitude readings
bmp388.setSeaLevelPressure(1025.0)

# Set standby time to roughly 1.3 seconds
bmp388.setTimeStandby(TIME_STANDBY_1280MS)

# Enable FIFO and set watermark
bmp388.enableFIFO()
bmp388.setFIFONoOfMeasurements(NO_OF_MEASUREMENTS)

bmp388.enableFIFO()

Enables the FIFO functionalities of the sensor

Returns value: None

bmp388.setFIFONoOfMeasurements(noOfMeasurements)

Sets how many measurements will be saved into the FIFO buffer

Returns value: None

Function parameters:

Type	Name	Description
int	noOfMeasurements	Number if measurement samples which will be saved into the FIFO buffer

Taking measurements

Next, in an infinite loop, we wait until the FIFO buffer is full, then we print out the measured values:

# Start continuous measurement in normal mode
bmp388.startNormalConversion()

print("Please wait for 13 seconds...")

while True:
    status, temperatures, pressures, altitudes, sensorTime = bmp388.getFIFOData()

    if status == FIFO_DATA_READY:
        for i in range(len(temperatures)):
            altitude = altitudes[i] if i < len(altitudes) else 0.0
            print(
                "{}: {:.2f}*C   {:.2f}hPa   {:.2f}m".format(
                    i + 1, temperatures[i], pressures[i], altitude
                )
            )

        print("Sensor Time: {} ms".format(sensorTime))
        print()
        print("Please wait for 13 seconds...")
    elif status == FIFO_CONFIG_ERROR:
        print("FIFO configuration error.")

    time.sleep(0.05)

REPL output

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Full Example

You can find the full example below:

from machine import Pin, I2C
from bmp388 import BMP388
from bmp388_constants import TIME_STANDBY_1280MS, FIFO_DATA_READY, FIFO_CONFIG_ERROR
import time

NO_OF_MEASUREMENTS = 10

# If you aren't using the Qwiic connector, manually enter your I2C pins
# i2c = I2C(0, scl=Pin(22), sda=Pin(21))
# bmp388 = BMP388(i2c)

# Initialize sensor over Qwiic
bmp388 = BMP388()

# Set sea level pressure for accurate altitude readings
bmp388.setSeaLevelPressure(1025.0)

# Set standby time to roughly 1.3 seconds
bmp388.setTimeStandby(TIME_STANDBY_1280MS)

# Enable FIFO and set watermark
bmp388.enableFIFO()
bmp388.setFIFONoOfMeasurements(NO_OF_MEASUREMENTS)

# Start continuous measurement in normal mode
bmp388.startNormalConversion()

print("Please wait for 13 seconds...")

while True:
    status, temperatures, pressures, altitudes, sensorTime = bmp388.getFIFOData()

    if status == FIFO_DATA_READY:
        for i in range(len(temperatures)):
            altitude = altitudes[i] if i < len(altitudes) else 0.0
            print(
                "{}: {:.2f}*C   {:.2f}hPa   {:.2f}m".format(
                    i + 1, temperatures[i], pressures[i], altitude
                )
            )

        print("Sensor Time: {} ms".format(sensorTime))
        print()
        print("Please wait for 13 seconds...")
    elif status == FIFO_CONFIG_ERROR:
        print("FIFO configuration error.")

    time.sleep(0.05)