In App Inventor, a Procedure is a block of code that can be called on to run at any time. This saves time and space when you need to run the same code over and over again.

1. From the Procedures blocks, add the Do block.
2. Name this procedure “SendToParticle“.
3. Add the Set Web1 block from the Web1 section to the new procedure.
4. Now we will assemble a string for the set Web1.Url by using the Join block from Text.
5. All together we will be joining the serverURL, deviceID, “/“, Fun, “?access_token=“, and accessToken.
6. Under the Set.Url block, we will add a Call.PostText block from the Web1 section.
7. To this we will add a Join block for sending to our Particle function via POSTrequest.
8. We will join “params=” and the Var value.

When ever this procedure is called Val will be sent via POST to:

https://api.particle.io/v1/devices/your-device-id/led?access_token=your-access-token