Display Multiple devices on one Project?

Is there any way to have Blink display data from multiple devices on a single Project dash?

I’d like to have a single screen show temperature/humidity from several different Spark Cores.


You can use the key from one project on multiple sparks - this would allow multiple sparks to one App-Project



+1. But you have to select different pins.


I think it would be a great extension to Blynk, for it to allow multiple devices on a Project.

I have a number of environment monitors around the place, these collect stuff like temperature, humidity, soil moisture. So I have a project for each monitor with all the details displayed.

It is a pain to switch through the different Projects to check the soil moisture on each monitor, it would be much better to have an additional Project with all the soil moisture readings in one place.

I don’t believe this can be done at present.


it could be done right now. You could just use same token for every hardware you have. In that case all data will come to 1 dashboard, so it is up to you to setup widgets and corresponding pins for specific hardware within same dashboard…

Also if your hardwares are different, than you most probably need to select “custom shield” for dash and setup all your sensor readings via virtual pins… It is more complicated so. But at least right now it is possible.


True, I could use the same token in all my hardware, which would allow me to display the soil moisture on the one project.

But then how do I display the temperature on a different project I setup just for displaying temperature? Is it permitted to have one Arduino open multiple connections to the server, so it can use multiple tokens?

Also how do I have the soil moisture displayed on one project, and also the same information displayed on another project I’ve setup for the device. Simply I want the display to be shared between two projects. I guess if I can open multiple connections between hardware and server, then I can have the hardware push to both projects.


Hi Nick,

Is it permitted to have one Arduino open multiple connections to the server, so it can use multiple tokens?

Blynk currently doesn’t support this. Mostly because arduino is not so powerful, so managing 2 open connections may be not so simple and cheap in terms of resources. @vshymanskyy please confirm.

Simply I want the display to be shared between two projects.

Right now this is also not possible in direct way, but there is a workaround - you could use Bridge! For instance :

  1. Setup 2 dashboards with 2 different tokens;
  2. Upload token1 to hardware1, upload token2 to hardware2; So you have dash1 reading all info from hardware1 and dash2 reading all info from hardware2;
  3. Now you want dash1 to be able to read some data form hardware2;
  4. In that case you have to make bridge from hard2 to hard1. In hard2 sketch you need to write a code - “I want to send my sensor data to hard1”;
  5. After bridge is done. Your hard1 will retrieve data from hard2 and you could forward it to dash1.

Brdige example you could find here. I agree that it is not straightforward and right now it is rather a “hack”, but at least it could be done. @vshymanskyy what do you think about making such complex sketch example?

Yes, it is a possible workaround, but it will cause more network load, and complicate things in general.
I don’t recommend it as actual solution. We realize that currently there is no clean way to do it, and we’re thinking about it :smile:


C’mon, network not at a problem at all right now. I think it is up to end user to decide if that worth it =).

Thanks for the suggestion and possible solution.

Unfortunately, my nodes are all battery powered and connected via radio so having one on to relay for the rest is a bit impractical.

They do all work through a gateway, which I’m currently expanding to interface to your server, so I’ll just have the gateway open multiple connections and duplicate the hardware events across the connections.

Thanks for the info and suggestions.


would there be a limit to the number of devices reading into a single project in this scenario? also how would you differentiate between device one and device two and device n if they are using the same authentication token?

You have to use different pins on each device. There are 32 virtual pins which can be used by that. For example, I have 2 ESP’s attached to my Mega with the same auth token, but for 1 I use vPin 32 and 31 to switch relays and vPin 30 to light up a LED strip attached to the other.


But I do use the Bridge widget in conjunction with of course.

OK. So based on what I am gathering there would be a limit to 32 devices per project at this time in the scenario where each device is using a single virtual pin?

That is correct. That is a way to do that. I believe vPins can handle an array of values though, so it could be even better than that. You could put all your stuff in on vPin I think, but I have to try that for myself.

There seems to be a lot of people on many different threads with the same needs and desires… that is for Blynk to have the ability to read and write many different devices in each project (dashboard). All the solutions I read about are hacks and work-arounds which do not really address the problem that most people are having. It would seem to me that it would be desirable for each project (authorization code) to have the ability to assign an identifier (say 0 to 255) to each widget and adjust the code at the device end to detect that code and only respond if it matches. That opens the door for Blynk to become a true home automation system rather that just a remote control/monitoring system.

I can see in the future, the possibility of a widget which can group many widgets together for theme activation and the such all grouped together on a special “Themes” dashboard…

I would be interested to hear if anyone agrees with this comment.


Check out LoPy on Kickstarter. Make one device a node and then you can connect up to 100 more. They have a stretch goal to make it Arduino IDE compatible. It would sure work nice for some of the home monitoring projects I’ve seen people building in this community. Maybe some day it will work with Blynk?