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! Check connections and jumper address! | begin() got no answer from the board within 500 ms. Check that the Qwiic cable is seated at both ends and that the address in your code matches the ADDRESS switch. | Reseat the cable, set the address in the code to the board's address (0x30 by default), and reset the controller. |
| The reading does not look like an H2S value | The examples are written with another gas's preset, such as SENSOR_CO or SENSOR_O3. | Pass a sensor type for this board's H2S cell, as the next row says. |
| The H2S reading is about 2.6 times too low | The libraries' hydrogen sulphide preset, SENSOR_H2S, is written for the SGX-4H2S-100 cell at 1200 nA per ppm. This board carries the SGX-4H2S-300 cell, whose datasheet gives an output signal of 460 ± 140 nA per ppm, and the reading is divided by the preset's sensitivity. | Do not use SENSOR_H2S unchanged. Pass a custom sensor type with the SENSOR_H2S settings and 460 nA per ppm, as Quick Start shows. |
The reading stays at 0.00000 | The library returns 0 for any result below zero. | A reading of 0 is expected when the calculated value is negative. To shift the zero point, setCustomZeroCalibration() adds a voltage offset before the conversion. |
MicroPython: Board not recognized, please pass an I2C object manually | The module opens I2C by itself only on the boards it recognises: ESP32 and ESP8266 builds of MicroPython, and one Soldered board's own build. | Create an I2C object for your board's SCL and SDA pins and pass it to ElectrochemicalGasSensor, as the example does. |
| The board is wired to a 5 V supply | The board has no regulator and runs from 3.3 V only. | Power it from 3.3 V through Qwiic or the 3V3 pin. |
Still blocked?
Ask on the community forum. Include the following so someone can reproduce it:
- product name and SKU: Soldered Electrochemical H2S Gas Sensor Breakout (Qwiic),
333331 - 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