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Plantower sensor always stops

My new SCK 2.1 is connected and working, either with battery or USB power. After a few seconds, however, the PM sensor fan stops and never restarts. I have tried various power supplies and cables, but always with the same stopping result. Blue plastic is off and I don’t notice anything in the way of airflow.

I notice I have no history for tvoc or eCO2; also history of zero all the time for the PM categories.

hostname: Smartcitizen7088

ESPversion: 0.9.8

ESPcommit: e283e58

ESPbuilddate: 2021-08-26T16:39:05Z

SAMversion: 0.9.8

SAMcommit: e283e58

SAMbuilddate: 2021-08-26T16:38:29Z

updateNeeded: false

I’d appreciate any help. Thanks!

Duane E.

Take a look at this thread and check the troubleshooting steps.

This may be the same problem as the two of us are having.

Wonder if it’s hardware and they shipped a bad batch of the PMS5003, or if perhaps the 0.9.8 firmware introduced a regression?

Thanks for the response. Using the “CLI” would be a first time experience for me, but I may be forced to try digging into that. It won’t be today though.
What I do know is that the PMS5003 is working. It just always stops and that’s a pretty good explanation for all my particulate matter readings being 0. To me, that would suggest this is not a hardware issue. Add to that my eCO2 reading which started as 400, but is now always 411–which is more likely not a reading at all.
Still more telling would seem to be that while I see history for all other things, there is no history at all for eCO2. It is also totally absent for TVOC.
At least in my case, there is more wrong here than just the PMS5003.
Please let me know if there’s anything I can do to help. It kind of seems that we are trying to deal with the same thing.

Wonder if it’s hardware and they shipped a bad batch of the PMS5003

I am leaning towards the bad batch idea; In fact I have a thought that Seeed Studios might have dropped the ball on QA testing. Something for FablabBCN to discuss with them. Your testing evidence and others too is ammunition for that discussion. @pral2a1 @pral2a

After working with the IDE, I find:
PMS5003 fan is always silent/off EXCEPT . . .
“read pm” turns on the fan and it stays on until next read, when it turns off.
“monitor pm” also keeps the fan on, but always reports only 0
jtleniger’s post shows VOC and eco2 sensors enabled; mine are always disabled
they refuse to be enabled, showing only “unrecognized command”
why eco2 at 411 and 1 VOC are still published–I don’t understand
a new install of github 9.8 firmware changes nothing
This seems to indicate trouble beyond or other than a bad sensor since part of the problem is that the firmware also refuses to allow below 60 seconds for the sensor interval.

My General understanding from other threads is that the PM Sensor is turned on only just before it is to be read; then turned off afterwards. This is done to save power. Also understood that the PM sensor requires a few seconds (15 ?) to get up to speed and warmed up before a reading. So, the turning on and off behaviour is deliberate ie ‘normal’. Also; turning the thing off will make it last longer; as less dusty air will pass through which could clog the sensor in some applications. (noting @oscgonfer earlier comment)
Saving power in context that some kits are run on batteries (only) such as the bike project.

Other than that I cannot comment; but I will be looking at the code for my own purpose later today or later this week; I can check it out to see if there is anything obvious ; cannot promise anything.
@victor or @oscgonfer could comment further.


PM sensor should be only on during 15s every measurement interval. Per default, the sensor interval is 60s for all the sensors, but the PM sensor is every 5’, so it would be on for 15s, then off until the 5’ are over. Is the behavior as described or does it never turn on again after 5’?

Regarding eCO2 and tVOC: the sensors are off until the stabilization period is over, which is 5’ after boot. Then, they should measure normally. Do they measure after 5’?


The PM sensor never turned on at all, unless I went into the shell and said “read” or “monitor.” Then it would turn on, but never reported anything but zero for PM.

The eCO2 and tVOC sensors are shown as disabled and refuse a command to be enabled.

In the last couple of days, however, nothing works at all. All I have is a flashing green LED. I’m not able to do any kind of reset no matter what I try. I have disconnected everything and started again, but still there is nothing but a flashing green LED.

I’d be happy to hear what I can do about this,

Hi @duerstad,

This is clearly a hardware issue that would fall into SEEED’s warranty conditions. This is the email you should write to:

You can mention this forum post for their reference.

Apologies for the issues. I hope it gets resolved

I appreciate your kind wishes, but this isn’t working. I’m told to send everything back, which should cost about $100 for shipping. I’m supposed to believe that I will be reimbursed. The basic unit only flashes green anytime there’s power. No one even addresses that, but I’m supposed to believe that the Plantower is the problem, which seems unlikely. I’ve been cooperative and patient about this, but if this doesn’t get better, I think people should be warned about this kind of risk–ending up with nothing for over $100. I don’t think it’s my responsibility to figure out who should take responsibility for this. Smart Citizen seemed a good idea, but not when it ends up like this, and I don’t appear to be alone in wasting a great deal of my time here.

Hi @duerstad It seems you have two issues.
(a) the eCO2 and tVOC sensors not being enabled
(b) the PM sensor apparently not operating.

In SCK 2.1 these sensors both connect via the Urban board; which is plugged onto the Data Board via a 16 pin connector.

The below advice is obvious to someone that is technically trained and maybe you have already gone through the recommended checks but just in case I have provided it below.

In my own experience; I have found that it is possible for the Urban board sensors to be apparently working but the CCS811 eCO2 and tVOC sensor not recognised; and the PM sensor also affected.

What I found was that the Urban Board was not properly seated onto the Data Board.

It ‘appeared’ to be connected properly; but in fact there was a tilt on the board and this caused a very slight gap (<0.5 mm) to appear on the outer side of the connector. when I straightened the board and made the connector sit flush on both side; then the CCS 811 sensor started working. (The SCK2.1 needed to be rebooted of course.)
Along similar lines; it’s also possible for one or more pins on that 16 pin connector to become bent; so that it does not go into the female receptacle properly. It can cause the same symptoms.
Also; it is possible for dust or debris to affect the pins on this connector.

So; I recommend that you:
(a) remove power from the SCK; including the battery.
(b) disconnect the Urban board; examine it closely for any damage. The PCB tracks are mostly covered by laminations; but if there is damage to the board then maybe it is visible as a line or a crack.
(c) examine closely (magnifying glass and strong light) the connector on both board.
(d) straighten any bent pins; remove any debris etc as may be necessary
(e) replace the Urban board onto the connector; make certain that every pin goes into appropriate socket and that the Urban board sits in a parallel plane to the data board.
Also check that the 8 pin cable going to the PM sensor is properly seated at both ends[
(f) Plug usb and battery back in; connect USB to computer and engage Arduino CC and open the monitor screen.
(g) observe closely the text displayed on the terminal and what the various messages say during the boot up.
then run through the sensors and i2c command and see if the ccs811 and pm devices are now recognised and (after a delay) deliver readings.
Note that CCS811 sometimes takes a few minutes to deliver readings; as does the PM sensor. So; give it 5 mins or so whilst observing the sensors output on the Arduino Monitor display.

I do not know where you are in the world; but $100 for shipping seems excessive to me. May I suggest that you look at both UPS and Fedex; one of them will be cheaper than the other. I would expect to pay no more than USD$50 and probably less.
Did you purchase the kit direct from Seeed Studios in Shenzhen/HongKong or did you purchase through Mouser/Digikey ? Have you contacted them and requested a Return Material authorisation ? If you have that and they say your freight cost will be reimbursed then I think you can rely on it.



Actually the issue at present is that no matter what I do, the main board continues to flash/pulse green more or less on and off.

I’ve done all the suggested things when it still more or less worked and reported some results. Now it simply flashes green—nothing works.

There is no bootup; hasn’t been for about a month by this time.

As for UPS: $116.47

And Fedex: $133.33

Either from southern Minnesota in the US.

I don’t imagine anyone would risk money like that for something worth even less.

The issue of cheap shipping from China to the US vs such expensive shipping as this from the US to China has become a sticking point. This is well known, probably also to Seeedstudio.

Anybody know anything about what that green pulsing light may indicate?

For any and all who have tried to help; I appreciate it, but this has gone nowhere. Happy New Year.

Hi @duerstad

At the risk of trying your patience please can you detail what steps you have taken of the following.

  1. Reset the device using the flat button on the board (silver color). Generally; the green led flashing tells you that the device is in file upload mode which happens during setup process.
    Basics (just checking)
    You HAVE gone through setup yes ?
    The device connects to your wifi right ?

  2. Update of firmware to current version 0.9.8 both SAM and ESP need to be done at the same time. Please confirm using the version command via the monitor (see 3).

  3. Connect the device to your laptop or of using usb and monitor the output by using Arduino CC ‘monitor’ screen.
    What messages does the device tell you about what is happening after a power up or reset button pressed.?
    If you can copy and paste some of the output it would help to diagnose your issue(s).

See how you go with those basic checks

The flat silver button does nothing. I have tried pressing it, holding it, both of those in combination with the power button. Nothing changes the pulsing green light.
In the past, some things did work, as my earlier posts show. This is not the case now.
If there is some way of resetting which I have not tried, I’d like to know about it.
It’s interesting to read that the green has something to do with upload, but what I need is a way to get beyond the green light.

You have a faulty kit. (flat silver button performs reboot; also sets mode to show virtual filesystem allowing firmware to be installed. Also sets kit into setup mode. It does quite a lot.

May I suggest in the first instance to contact whomever you purchased it from and seek a replacement; please let us know here a summary of the interaction and the result.


Is this how Seeed operates? I’m open to suggestions on how to deal with them.
I suspect they have gotten away with this before.
This is not for “Smart Citizens” any way I see it.
Seed thinks this is a reasonable response on their part:

Sorry we cannot cover the freight fee since it is more than 10 days after delivery.
We can offer you coupon code of $10 for discount for your future order.

Please feel free to contact us if you have any questions. Thanks.

Best Regards!
Seeed Bazaar Customer Support Team

I can empathise but since I am a peer to you, can offer no suggestions.

This whole issue of the faulty PM Sensors (maybe also Urban boards) is causing concern for the FablabsBCN team; I am aware of it. But there has been no announcement of a solution just yet.

I could speculate but it’s pointless guessing. Just to say that the apparently faulty sensors issue solution likely resides with the manufacturer. (Plantower) Seeed just put them in the box. But it’s not easy communicating to a Chinese company. And then there’s the vexed question of freight cost; who pays ?

Requires patience as FablabsBCN work through it.

Hi @duerstad,

Can you email us at with a brief description of the issue and we try to move it from there?