Execute measurements with SensorBridge

The following steps show how to use this driver on a Windows system using the Sensirion SEK-SensorBridge to execute a simple measurement.

  1. Install the SFX6XXX driver and all required packages as described in Installation.

  2. Install the driver for the Sensirion SEK-SensorBridge

    pip install sensirion-shdlc-sensorbridge
    
  3. Connect the SEK-SensorBridge to your PC over USB

  4. Connect the SFX6XXX sensor to the SEK-SensorBridge

  5. Run the example script from the root of the repository.

    By default the script assumes the SensorBridge is connected to COM1 serial port. If this is different on your system, pass the port in use with the --serial-port parameter as outlined below.

    python examples/example_usage_sensorbridge_sfx6xxx.py --serial-port <your COM port>
    

Example script

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# (c) Copyright 2024 Sensirion AG, Switzerland
#
#     THIS FILE IS AUTOMATICALLY GENERATED!
#
# Generator:     sensirion-driver-generator 0.40.1
# Product:       sfx6xxx
# Model-Version: 2.3.1
#

import argparse
import time
from sensirion_i2c_driver import I2cConnection, CrcCalculator
from sensirion_shdlc_driver import ShdlcSerialPort, ShdlcConnection
from sensirion_shdlc_sensorbridge import (SensorBridgePort,
                                          SensorBridgeShdlcDevice,
                                          SensorBridgeI2cProxy)
from sensirion_driver_adapters.i2c_adapter.i2c_channel import I2cChannel
from sensirion_i2c_sfx6xxx.device import Sfx6xxxDevice

parser = argparse.ArgumentParser()
parser.add_argument('--serial-port', '-p', default='COM1')
args = parser.parse_args()

with ShdlcSerialPort(port=args.serial_port, baudrate=460800) as port:
    bridge = SensorBridgeShdlcDevice(ShdlcConnection(port), slave_address=0)
    bridge.set_i2c_frequency(SensorBridgePort.ONE, frequency=100e3)
    bridge.set_supply_voltage(SensorBridgePort.ONE, voltage=24)
    bridge.switch_supply_on(SensorBridgePort.ONE)
    i2c_transceiver = SensorBridgeI2cProxy(bridge, port=SensorBridgePort.ONE)
    channel = I2cChannel(I2cConnection(i2c_transceiver),
                         slave_address=0x24,
                         crc=CrcCalculator(8, 0x31, 0xff, 0x0))
    sensor = Sfx6xxxDevice(channel)
    (product_identifier, serial_number
     ) = sensor.read_product_identifier()
    print(f"product_identifier: {product_identifier}; "
          f"serial_number: {serial_number}; "
          )
    sensor.start_o2_continuous_measurement()
    for i in range(100):
        try:
            time.sleep(0.5)
            a_flow = sensor.read_flow()
            print(f"a_flow: {a_flow}; "
                  )
        except BaseException:
            continue
    sensor.stop_continuous_measurement()

Execute measurements using internal Linux I²C driver

On Linux systems it is furthermore possible to use the Linux user space I²C driver directly. How this can be done is shown in the following.

  1. Install the SFX6XXX driver and all required packages as described in Installation.

  2. Connect the SFX6XXX sensor to the I²C port of your system (for example to the I²C port 1 of a Raspberry Pi).

  3. Run the example script from the root of the repository.

    By default the script assumes you have the sensor connected to /dev/i2c-1. If this is different on your system, pass the port in use with the --i2c-port parameter as outlined below.

    python examples/example_usage_linux_sfx6xxx.py --i2c-port <your I2C port>
    

Example script

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# (c) Copyright 2024 Sensirion AG, Switzerland
#
#     THIS FILE IS AUTOMATICALLY GENERATED!
#
# Generator:     sensirion-driver-generator 0.40.1
# Product:       sfx6xxx
# Model-Version: 2.3.1
#

import argparse
import time
from sensirion_i2c_driver import LinuxI2cTransceiver, I2cConnection, CrcCalculator
from sensirion_driver_adapters.i2c_adapter.i2c_channel import I2cChannel
from sensirion_i2c_sfx6xxx.device import Sfx6xxxDevice

parser = argparse.ArgumentParser()
parser.add_argument('--i2c-port', '-p', default='/dev/i2c-1')
args = parser.parse_args()

with LinuxI2cTransceiver(args.i2c_port) as i2c_transceiver:
    channel = I2cChannel(I2cConnection(i2c_transceiver),
                         slave_address=0x24,
                         crc=CrcCalculator(8, 0x31, 0xff, 0x0))
    sensor = Sfx6xxxDevice(channel)
    (product_identifier, serial_number
     ) = sensor.read_product_identifier()
    print(f"product_identifier: {product_identifier}; "
          f"serial_number: {serial_number}; "
          )
    sensor.start_o2_continuous_measurement()
    for i in range(100):
        try:
            time.sleep(0.5)
            a_flow = sensor.read_flow()
            print(f"a_flow: {a_flow}; "
                  )
        except BaseException:
            continue
    sensor.stop_continuous_measurement()