No data from SDS: How can I debug?

skilfing · February 17, 2021, 4:44pm

Hi

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

twoStageOTAUpdate
R/ SDS011 version date
/R SDS011 version date
HTTP GET: firmware.sensor.community:443/airrohr/update/latest_en.bin.md5
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 sensor.community - BME280
Succeeded - api.sensor.community
## Sending to madavi.de: 
Succeeded - api-rrd.madavi.de
Time for Sending (ms): 413

Device status

Parameter	Value
Firmware version	NRZ-2020-133
ST:1
SDK:2.2.2-dev(38a443e)
Core:2.7.3-3-g2843a5ac=20703003
lwIP:STABLE-2_1_2_RELEASE
glue:1.2-30-g92add50
BearSSL:5c771be 
Free Memory	31200 
Heap Fragmentation	3 %
Last OTA	6 min, 52s 
NTP Sync	1 
NTP Info	192.168.1.1 (?) reachable: Yes 
Time (UTC)	Wed Feb 17 16:20:11 2021  
Uptime	6 min, 52s 
Reset Reason	Power On 
 
SDS011	 
 
only errors
WiFi	0/-58/0 
OTA Return	200 
SDS011	2      <--------------increases
 
Number of measurements	2 
Time spent uploading	492 ms

Current data

|Sensor|Parameter|Value|
| --- | --- | --- |
|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!

irukard · February 17, 2021, 4:54pm

Could you post photos how did you connect cables.

skilfing · February 17, 2021, 6:12pm

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

nephilim · February 17, 2021, 7:47pm

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

pjg · February 17, 2021, 8:12pm

RX<=>TX
TX<=>RX

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

skilfing · February 18, 2021, 10:30am

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

nephilim · February 18, 2021, 10:51am

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

pjg · February 18, 2021, 11:40am

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?

skilfing · February 19, 2021, 1:25pm

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

skilfing · February 24, 2021, 11:02pm

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!