I cannot call up some of the blocks in the following code


I am receiving help from someone who showed me a block layout so I could copy it and build it myself instead of using an .ala file. He has a "When BluetoothLE1.Connected" and a plug in that says ""Set LabelMessages.Text."

I tried calling up various attributes in the Design menu but I am unable to locate these blocks. Can anyone suggest to me what I might need to do?

Here is the documentation of the BLE extension

You can find the Connected event in the BLE drawer in the blocks editor

And LabelMessages is just a label... you can rename the components as you like

See also the BLE tutorials here



I just do not see what you are saying. I easily found the block "When BluetoothLE Connected" but the green "Set" blocks do not allow be to change the first word from "Connected" to "LabelMessage" and I cannot find a block with that "label."

Isn't there a tutorial that covers all of the block functions, their sub-components, and their functions? Just the pretty colored blocks and not technical jargon associated with them.

No tutorial but there is documentation.


and an e-book explaining how to use App Inventor discussed in
these resources to help you learn to use the AI2 tools. A very good way to learn App Inventor is to read the free Inventor's Manual here in the AI2 free online eBook App Inventor 2 Book: Create Your Own Android Apps ... the links are at the bottom of the Web page. The book 'teaches' users how to program with AI2 blocks.

There is a free programming course here Course In A Box and the aia files for the projects in the book are here: App Inventor 2 Book: Create Your Own Android Apps

How to do a lot of basic things with App Inventor are described here: How do you...? .

Also look here App inventor español. Offline. Tutorial. Ejemplos. Instalación. Códigos. Juegos. Curso gratis de App inventor. and here Tutorial Index | imagnity for more tutorials including Imagnity.com List Tutorial, Mirrored - @Saj

Learn about components Component Reference
and visit the Library The MIT App Inventor Library: Documentation & Support Help>Library on the MENU


Thank you. I knew it had to be out there but I have difficulty finding many things here. I appreciate your suggestions and the extra links!

Hi, I have received helpful advice from several people here but I am still unable to apply it to my situation. I have block code, but no designer code, from someone who said "do it like this . . ." He was replicating what I was trying to do which was to connect to my ESP32C3 via BLE and display three parameters. Given this, the design page should have a button and three labels to display the data.

All I can guess is that this person has something else in his design page and I hope someone here will recognize it and tell me what it is. After some UUID assignments, there is a logic block "When BluetoothLE (is) Connected," "Set LabelMessage.Text to." And this is my nightmare . . .

I cannot find any block features on the lext that have a "Set LabelMessages.Text." I am including an image of what I encounter. Someone said that "LabelMessages" was a user-created term but there is only a drop-down box with choices here, not a fill-in-the-blank block.

My prayer is that someone says "Put XXXXX in your Design window and "LabelMessages" will appear as a drop-down choice in the Block window.

Thank you, ahead of time, to anyone who can help me understand why I am having issues here.


that is a label component. You can find it here and drag it to the designer like with the other components:

you can change its name to "LabelMessages" and in block you will see the block:

"LabelMessages" is the name of the label and "Text" is the property of the component.

In the Designer, there is a Rename button.

It gets active when you select a component you want to rename.

Unfortunately, this board is not accepting pictures at the moment.
It also is giving me 502 errors completing this post.

Uh oh ...

Okay, I got it posted.

This screen shot is from an inconsiderate user who posted code where none of the components had names as to their purposes, yet they asked for help fixing their code.

(I had to guess the user name components myself and rename them before I could make inroads into their logic.)

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Thank you so much! I had no labels in the original app so I was unable to find the specific blocks until I had incorporated a label. Learning slowly!

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