Broken USB socket, deriving power via Vin

SDS011 Stop Working

Attempting to change the cable on my sensor I managed to break the USB socket (just used for power). The whole project has worked faultlessly for the best part of a year. No problem I thought, just power direct to Vin and Gnd pins. Temperature and humidity sensors work fine, but SDS011 particulate refuses to work. Can this have anything to do with the way I am powering it? I have ordered a replacement node MCU but don’t have a lot of confidence that replacement will cure its ills.

Any pointers appreciated.

Can you send a picture?

Power on Vin and SDS on VU ? It should work.
Do you have at least 1,5 A out of the PSU or USB charger?

Or can you test the SDS with the USB to TTL dongle you should have received?

With the USB socket gone, the vu (V-usb) is no longer funcional probably.
The SDS011 needs 4.7~5.3V to operate (datasheet)
You could use a 5V powersource to power the SDS011 directly and power the MCU with the same powersource through the Vin pin. Make shure they have a common ground.
A replacement MCU will do the trick.

Thanks for your reply, the PSU is the same charger I was using before it stoped, rated at 1.5 amps so I assume OK. I will have a look but I dont think I had a TTL dongle (it wasnt a kit, I purchased the parts direct).

Thanks for your reply, I will see if I can test the SDS011 directly as you suggest. Can you elaborate on what you mean by V-usb being no longer functional? It does appear that at least part of the MCU is still functional.

@tadder is right.

It seems that the VU only gets current form the USB and not from the chip itself (which could be powered by the Vin). So if the USB plug is broken/not connected, there is nothing coming out of the VU pin.

That’s correct. The voltage of the vu pin is taken directly from the usb connector ( and thus the only direct source for 5V).
I guess the MCU works when powered via the Vin pin??

Yes, the MCU works fine powered from Vin. I guess I will have to wait for my replacement.

Thanks for that. So clearly I am waisting my time trying to use VU.

Thanks to everyone for their help, which has saved me a lot of head scratching.
In order to assist others with the same problem I have renamed the topic “Broken USB socket, deriving power via Vin”

1 Like