Ble charactertics adc

I'm totally new to MIT app inventor and I would like to build a BLE application that will receive a data from my there any documentation that will help me to build application.

welcome to the Community.
You can find huge documentation about BLE by doing a search in the forum.
You'll find theory, scripts, examples, chuncks of code...
Many Power Users have ton's of "ready made code" on their web sites. Please search for @ChrisWard, @Juan_Antonio, @Taifun (but also many other PU's !!!) posts to find the addresses of their web sites.
Best wishes.

Hi, I had tried to connect Ble with and was able to connect. But when I tried to add the characteristic and services, I was able to connect and got runtime error. Can you help us on this.
efx_iot.aia (192.3 KB)

In your BLE bytes received event you blindly assumed you had 3 bytes in your list.

Add an if then test against length of list bytes received to detect a short list, and notify you more gracefully.

1 Like

according to what @ABG has already said, you are trying to access to a non-existent element of a list.
You could try something like:

Best wishes.

1 Like

For good measure, post the microcontroller code here, so we can see what you sent.


hi all,
I have understood my mistake and the code works fine thank you all.

Would you mind posting what works, for others to learn?

It probably only sent 1 byte from the arduino. In hard blocks it read 3 bytes.