list index too large app inventor

[AbiiSl]

Hi there I'm trying to use 3 ultrasonic sensors and  a PIR sensor  so that's 4 sensors now Im struggling with the app, does anyone know whats wrong with the code?

[Chris Ward]

Hello AbiiSI

We need to see the script/sketch of the microcontroller (e.g. Arduino)

[TimAI2]

You probably need to first test the response back from bluetooth - it may not be what you expect it to be, e.g. A|B|  instead of A|B|C|D

[Chris Ward]

Hi again AbiiSI

Is that screenshot of your Blocks all of your Blocks? - looks like some code is missing. If not, please capture them again and this time use App Inventor's built-in capture feature so that we get a top quality image that we can view & zoom:

https://www.professorcad.co.uk/appinventortips#TipsBlocks  How to create an image of your Blocks and add it to your Forum Post.

Currently,  it looks like Clock 1 is running before the process is ready! Note that The App Inventor Process must be set to be faster than the microcontroller sends the data. For example, microcontroller sends every 2 seconds, App Inventor Process (Clock Timer) cycles every 1 second.

[ABG]

Your messages are being broken up by the Clock Timer on their way in.

Solution: Use a message delimiter ...

Use println() to separate messages when you transmit.

Set Delimiter = 10 in BlueTooth Designer.

Check for Bytes Available > 0 in blocks,

but then request -1 bytes to get only full  messages.

See https://groups.google.com/forum/#!msg/mitappinventortest/lVaCyAeWm_4/ADjvy05wAwAJ attachments.

ABG