Dead OLED + 0 values for sensors


I have DIY AQ Kit 1 and soldered it up last night. I successfully deployed the blink program and the LED flashes. I then moved on to flashing the C02_PM_SHT_OLED_WIFI program. A first I thought it had failed as the final message was:

Writing at 0x00040000... (100 %)
Wrote 394160 bytes (274031 compressed) at 0x00000000 in 6.8 seconds (effective 463.6 kbit/s)...
Hash of data verified.

Hard resetting via RTS pin...

with no further output on the console and no change on the OLED screen (remains black).

However I then set connectWIFI = true; and recompiled and flashed to the device. I could see the AIRGRADIENT wifi network so at least the WEMO D1 is working. I was able to successully join my WiFI network and then I attached the serial monitor. In this output I can see that all my sensors are rerturning what looks like bad data.

First 5 minutes output was like so:


and then the outout changed (possibly after I registered the device?):


I have seen some other threads that discuss the particulate sensor can take hours/days to start returning values but I also have null values from the temp and humidity sensors.

My soldering isn’t brilliant but hopefully not that bad :wink:

Any pointers to how I can debug are greatly appreciated.


It could be something wrongly soldered. Can you please post pictures of your built. Front and back side of PCB and all soldered components.

While taking the photos, I noticed some less that ideal joints. So I revisited them with the soldering iron and now when I plugged in the power, the display came on immediately. I then attached the serial monitor and I can see non-zero values for the sensors.


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Great that it works now. Yes often the solder joints can create problems.