Broken USB socket, deriving power via Vin

1

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.

2

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?

3

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.

4

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).

5

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.

6

@tadder is right.

https://arduino.stackexchange.com/questions/75645/vin-vu-pins-of-nodemcu-v3

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.

7

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??

8

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

9

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

10

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”

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