Device wifi not showing up - check the USB power supply

Hi everybody

I have lost a few hours figuring out what was wrong, so I would like to share my experience.

I bought my second pre-installed Nettigo kit, and followed the instructions carefully.
The red LED of the Power supply was working, the blue LED of the device was blinking, but no configuration (“airRohr*”) WIFI was detectable, tried with my laptop, tablet, fairphone…

So, I checked all connections, uploaded 3 different firmware images, cleared the flash multiple times, restarted from zero… Nothing would work!

In the guide, I then saw under “USB cable problems?” that you could see the logs of the device.
So, I installed Tera Term and connected to the device via the USB/serial connection, and then I saw in the booting message that everything looked fine:


And indeed, the WIFI was working all right!
This made the USB power supply the main suspect, and indeed, tried charging my phone with it, it did not work. Used another USB power supply, and worked like a charm since!

I guess the supplied USB power supply in the set is a bit too cheap to be true.


Yes. The power supply is often an issue (I have solved at least 10 issues like that in the last year). Always check the amount of current which the PSU can produce (mA) basically for setups with a lot of sensors (for ex. SDS11 + DNMS + BME280 + custom PCBs + …). If you use a multi-USB to test a few sensors before giving them away, you should think that the total amount of mA will be divided by the number of AirRohrs. Just look at the datasheets of each component to sum the total consumption.

I think we found a decent alternative. Load tests are very promising. Stable 5.15V up to declared 1.5A. Should be more than enough to power up every possible configuration.


Now we concentrate our efforts on finding high quality flat 3m micro USB cable. It’s easy to find good cable with power lines only. But we will lose debugging and programming capabilities in exchange for stable voltage and less potential problems.

Is cable with no data lines worth consideration?

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