I am experiencing an issue when updating the firmware on the CO2 sensor. After uploading the bootloader and firmware, the display does not return to showing CO2 and temperature. Instead, it continues blinking at a rate of 2 times per second. What should I do?
This is the standard behaviour for a ‘bricked device’. The first few seconds after power up it will be in the two blips mode, you can hit the flash button in those few seconds and the flash should resume.
There’s a lot more posts with more detail, search with keyword ‘Unbrick’.