Triggers don't work

Hi, I’m using Arduino Uno with Yun Shield, web and iOs dashboard. I tested several triggers and scheduled some events yesterday and it worked great. Thanks a lot for such a convenient and easy to use service. But unfortunatelly, today triggers doesn’t work.

I hope, so it is a temporary bug. Is it? When does it suppose to work again?

And one more question, please.

In the list of available data there is CO2, but if I choose it, graph doesn’t work. Are you going to fix it?

Thanks a lot for your answer!


Hi Alexander.

We’re not aware of any across the board issues with Arduino triggers at the moment, though we do have some major outstanding issues with Arduino scheduled events. Could you tell us a bit about the triggers which aren’t running for you so I can try to reproduce/help troubleshoot?

Which widget / sensor are you having trouble graphing CO2 with?

Thanks a lot for your prompt answer!

It seems to me, that I understood the reason. I will try to describe the case.

  1. Actuator1 controls light. Event is scheduled with Cayenne, it turns on and off every day.

  2. Actuator2 turns on the relay for 5 seconds, but only in case when light is on. I made it with Cayenne_in function, where I check if the light is on. Trigger should run Actuator2.

if (L){
t.pulse(Relay, 5000, LOW); }
Cayenne.virtualWrite(V17, LOW);

After 5 seconds Relay turns off and virtual pin returns to LOW. Actually, this is the problem. Because trigger runs once and after virtualWrite lo LOW the trigger doesn’t work anymore.

I hope, I explain the situation good enough.

Thanks in advance for your help and time!


Talking about CO2, I’m using MH-Z19 sensor, I virtualWrite data to virtual pin.

There is no CO2 option when I set widget, but later in settings I can choose CO2 as data and ppm as unit. But if I do so, it doesn’t work, no action in widget (value, gauge, graph, doesn’t matter). So I forced to use temperature as data and F as unit.

Rsiegel, hi!

I’m still waiting for your reply :slight_smile:

Could you please help me?

As far as your CO2 sensor you can just do a standard virtualWrite instead of sending it as a temperature. that way it doesn’t have a unit but also doesn’t have an incorrect one.

It seems that you can not create any more a trigger. Drag and drop the device into “if” field does not work.

@tudor.teodorescu are you dragging and dropping the parent Raspberry Pi / Arduino / MQTT / LoRa device into the ‘if’ field? That should work, at least it is for me. Then you can select the individual sensor/actuator you want to base the trigger on from the drop down menu.

I know it doesn’t work if you drag an individual sensor/actuator to the ‘if’ box. I’d like to improve things so that works in the future to make the process a bit more user friendly.

@a.ivashin I’m not sure if this CO2 data option should have been available to you, or if it slipped into our production site before it was ready. The CO2 widget that it’s intended for is not yet released, but will be in the next batch of widget updates.

That might explain why you’re seeing odd behavior from it, and why it was only available when you edited the custom widget, and not during widget creation.

Another option would be to pass the sensor data via our MQTT ‘Bring your own thing’ API in the format:
co2,ppm=value. This appears to work to create a CO2 widget that is displaying my data OK. You can read about connecting your device via MQTT in this documentation.

@adam, @rsiegel Thanks a lot for your answers!
Regarding CO2, I’m doing virtualWrite and read it with Cayenne widget. I’ll try to use MQTT, no problem.

But the main issue was about trigger. I wondered if I could use trigger to turn the relay on for 10 sec every time, when the temperature is below specified value. Actually, I can go another way and write all the logic inside arduino sketch without using trigger, but it’s not as convenient as using standard trigger.

Is it possible to use Cayenne slider to send value to arduino? After that program will compare it with sensor data and turn on the relay using t.pulse.

Can you try drag and drop the device on the left side panel into the “if” field? Because drag and drop the sensor is not featured yet :slight_smile:


The functionality you are asking for is going to come! We will allow for more robust trigger usage such as adding timer and more complex if/then logic. So, hang in there!

Yes, I think so :slight_smile:


Thank you for your message. It is workind only on my phone (android) not on
my Windows PC. I tryed to refresh the page, to close and open again the
browser, but do not work.

That sounds great! Thank you guys for your work! Cayenne is an excellent product an I wish all your plans are happen! :grinning:

Is there any chance to subscribe for updates, so you send all the new features on e-mail?

Trying to drag and drop the Raspberry Pi does not work.

Same issue here. Triggers related to “objects” and not Notify aren’t working anymore. Simple trigger like “if motion” than “turn on light” stopped working. Using Raspberry PI.


@michal.z4nd4r Can I ask what RAM usage Cayenne is currently reporting for that Pi?

There are some users who have seen a memory leak with the Pi agent where it will grow over time to 95%+ RAM usage, and at that time I’ve heard reports of things not working correctly until the memory is freed by rebooting the pi. We do have a developer at work on that specific issue so hopefully it won’t be around much longer. That’s the first thing I’d check, and see if rebooting the Pi helps your triggers to fire again.


That sounds like it could be a browser issue – we’re not reproducing on our side. Could you let us know what browser, browser version, and OS you’re running the web dashboard on. Can you try to log into the web dashboard on an alternate browser to see if you can drag and drop the parent Raspberry Pi device into the IF box there?

Windows 10 + Microsoft Edge

@michal.z4nd4r Ignore what I said before, we located the issue with triggers and it should be resolved now. Please try again.