Forum Sensor.Community

No data from SDS: How can I debug?


As I’m not very experienced with NodeMCU yet I’m a bit stuck.
I’ve bought the kit, assembled and flashed it but I get no data at all from the SDS. I think it’s power related (fan not spinning, no flashing LED) but I don’t know where to start with debugging. I’ve measured the SDS 5V and GND PINs and there’s voltage so maybe it’s the data connection.

As advised in the troubleshooting section I’ve redone the cabling several times, reflashed and replaced some cables to no avail. Pictures are attached, maybe I’ve gone insane while trying to figure this out.

During the setup I’ve flashed the NodeMCU after assembly, might that have caused an issue on the SDS? Would anyone have some advice on how to further troubleshoot?

Debug log

airRohr: NRZ-2020-133/EN
mounting FS...
opened config file...
parsed json...
output debug text to displays...
Connecting to 123
....SNTP synced: Wed Feb 17 16:13:16 2021

R/ SDS011 version date
/R SDS011 version date
GET r: 200
output debug text to displays...
No newer version available.
WiFi connected, IP is: xy
Starting Webserver... xy
ws: root ...
ws: values ...
ws: root ...
ws: status ...
ws: root ...
ws: values ...
R/ BME280
Temperature (°C): 21.26
Pressure (hPa): 97253.69
Humidity (%): 39.14
/R BME280
## Sending to - BME280
Succeeded -
## Sending to 
Succeeded -
Time for Sending (ms): 413

Device status

Parameter	Value
Firmware version	NRZ-2020-133
Free Memory	31200 
Heap Fragmentation	3 %
Last OTA	6 min, 52s 
NTP Sync	1 
NTP Info (?) reachable: Yes 
Time (UTC)	Wed Feb 17 16:20:11 2021  
Uptime	6 min, 52s 
Reset Reason	Power On 
only errors
WiFi	0/-58/0 
OTA Return	200 
SDS011	2      <--------------increases
Number of measurements	2 
Time spent uploading	492 ms

Current data

| --- | --- | --- |
|SDS011|PM2.5|- µg/m³|
|SDS011|PM10|- µg/m³|
|BME280|temperature|21.5 °C|
|BME280|air pressure|972.50 hPa|
|BME280|humidity|38.1 %|
|WiFi|signal strength|-51 dBm|
|WiFi|signal quality|98 %|![sensor |666x500]

Any pointers are much appreciated!

Could you post photos how did you connect cables.

Accidentally deleted it, see picture in the edited post. Here from the other side.

It seems you swapped yellow and orange. TXD goes to D1.


Also check if the Dupont cable ends are tight enough. It is maybe just an electrical problem.

Thank you both
Switched the TX/ RX cables → no change.
Replaced the TX/ RX cables in switched position due to pjgs suggestion → no change.

The fan never spins up? It should run for a few seconds every two minutes.

I meant TX must be connected to RX and RX must be connected to TX.
The picture seems OK.

Can you send us a screen print of the configuration webpage of the sensor?

Haven’t you made a error in the fisrst attempt. It could have burnt a capacitor in the SDS011 or a pin…

There is no red light at all on the SDS011?

The fan never spins, I have never seen any LED light up on the SDS (NodeMCU flashes blue briefly).

I’ve ordered another SDS to rule out having fried something with the first assembly.
If you don’t have any other ideas what I could’ve missed I’ll report back when it arrives and I had a chance to test :slight_smile:

I’ve replaced the SDS011, seems like I have fried something on the first assembly, works like a charm now.
Thank you for your help!