Quick Start

SensorBridge Example

Following example code shows how to use this driver with a Sensirion STC3x connected to the computer using a Sensirion SEK-SensorBridge. It is assumed, that the sensor is plugged into port 1 of the SensorBridge and COM Port 1 is used on the computer. The driver for the SensorBridge can be installed with

pip install sensirion-shdlc-sensorbridge

import time

from sensirion_i2c_driver import I2cConnection
from sensirion_shdlc_driver import ShdlcSerialPort, ShdlcConnection
from sensirion_shdlc_sensorbridge import SensorBridgePort, \
    SensorBridgeShdlcDevice, SensorBridgeI2cProxy

from sensirion_i2c_stc import Stc3xI2cDevice
from sensirion_i2c_stc.stc3x.data_types import Stc31BinaryGas

# Connect to the SensorBridge with default settings:
#  - baudrate:      460800
#  - slave address: 0
with ShdlcSerialPort(port='COM1', baudrate=460800) as port:
    bridge = SensorBridgeShdlcDevice(ShdlcConnection(port), slave_address=0)
    print("SensorBridge SN: {}".format(bridge.get_serial_number()))

    # Configure SensorBridge port 1 for STC3x
    bridge.set_i2c_frequency(SensorBridgePort.ONE, frequency=400e3)
    bridge.set_supply_voltage(SensorBridgePort.ONE, voltage=3.3)
    bridge.switch_supply_on(SensorBridgePort.ONE)

    # Create STC3x device
    i2c_transceiver = SensorBridgeI2cProxy(bridge, port=SensorBridgePort.ONE)
    stc3x = Stc3xI2cDevice(I2cConnection(i2c_transceiver))

    # set binary gas
    stc3x.set_bianry_gas(Stc31BinaryGas.Co2InAirRange100)

    # Measure once per second
    while True:
        time.sleep(1)
        gas_concentration, temperature = stc3x.measure_gas_concentration()
        # use default formatting for printing output:
        print("{}, {}".format(gas_concentration, temperature))
        # custom printing of attributes:
        print(
            "{:0.2f} vol% ({} ticks), {:0.2f} °F ({} ticks)".format(
                gas_concentration.vol_percent, gas_concentration.ticks,
                temperature.degrees_fahrenheit, temperature.ticks))