Troubleshooting
Start with the symptom you can observe. Apply one change at a time, then retry the smallest Quick Start example.
| Symptom | Check | Fix |
|---|---|---|
ERROR: Can't init the sensor! appears instead of Sensor initialized successfully! | Does the address in the line that creates the sensor match the ADDRESS switch (0x30 by default)? | Pass the switch address, as the bridgeBoard example does with 0x30: ElectrochemicalGasSensor sensor(SENSOR_CL2, 0x30); in Arduino, adc_addr=0x30 in MicroPython. The libraries use the bridge transport only for addresses 0x30 to 0x37; any other address makes begin() look for the ADS1115 and the LMP91000 directly on the bus. |
| The init error appears and the address is right | Is the controller wired to SDA1 and SCL1 (or Qwiic), with 3V3 and GND? | Connect to SDA1 and SCL1. SDA2 and SCL2 are the board's internal bus between the ATtiny404, the LMP91000 and the ADS1115. |
| Readings look wrong for chlorine | Which preset does the line that creates the sensor use? | Use SENSOR_CL2. The examples use other cells' presets (SENSOR_CO, SENSOR_O3 and others), and the ppm value is calculated from the preset's sensitivity and gain settings. |
| The reading stays at exactly 0 | Is the true result below zero? | The libraries report any result below zero as 0. Set a zero offset in clean air with setCustomZeroCalibration(), as on the zero calibration page. |
MicroPython raises Board not recognized, please pass an I2C object manually | Did you create the sensor without an i2c argument? | Create an I2C object for your board's pins and pass it, as the examples do. The module only picks pins by itself on the esp32 and esp8266 ports and on one other board it recognises by its name. |
Still blocked?
Ask on the community forum. Include the following so someone can reproduce it:
- product name and SKU: Soldered Electrochemical Cl2 Gas Sensor Breakout (Qwiic),
333332 - controller board and software environment
- library or module revision
- complete error text or unexpected output
- connection method and power source
- a clear photo of the wiring