Need help for ListPicker function

[Charlotte_Loke]

@gordonlu310

This is the problem here (probably not your fault) - if you split an empty text at spaces, you will get the first item as an empty text.

Do you mean this block part? What can I do if I don't split an empty text at spaces?

@gordonlu310

And here, List is a list with a length of 1, so you cannot select item number 2 in a list with a maximum index of 1.

So here will be just 0 and 1 right?

[gordonlu310]

@Charlotte_Loke

So there will be just 0 and 1 right?

No, global list is just something like this.

@Charlotte_Loke

Do you mean this block part? What can I do if I don't split an empty text at spaces?

global Script itself is an empty text, so you cannot avoid it. If it is empty text, it probably means that it has received nothing or received empty text.

Because you set a conditional that executes only when BytesAvailableToReceive is > 0, it will do nothing.

[Charlotte_Loke]

So does that means that maybe I need to change the way of code in Arduino? Is there any way that I can change the blocks instead changing the code in Arduino?

@gordonlu310

global Script itself is an empty text, so you cannot avoid it. If it is empty text, it probably means that it has received nothing or received empty text.

Because you set a conditional that executes only when BytesAvailableToReceive is > 0, it will do nothing.

So how should I correct this part?

[gordonlu310]

You probably have to look into your Arduino code and check if anything is wrong with it.

@Charlotte_Loke

I can't find out the problem but I think there is no problem with the Arduino bcaus it works well when I run the serial monitor

BytesAvailableToReceive is currently 0. I am not an expert in this, but it seems that something is wrong.

[Charlotte_Loke]

Do you know Arduino? Because I can't really think of another method of sending the data to the MIT app inventor

[gordonlu310]

@Charlotte_Loke

Do you know Arduino?

Not much, but I am checking. I am checking it, but I don't see problems in the code (yet).

[Charlotte_Loke]

Ya so I think the problem is more on the MIT app inventor

[Charlotte_Loke]

@gordonlu310

BytesAvailableToReceive is currently 0.

So should I change the value instead of putting 0? Actually what is the meaning of this block BytesAvailableToRecieve?

[gordonlu310]

According to the documentation, it

Returns number of bytes available from the input stream.

[Charlotte_Loke]

So for this part it splits list with a space is it? e.g. [F, ,100]? is it like this? so index for F is 0 and index for 100 is 2

[gordonlu310]

The split at spaces block returns a list splitted in spaces. For example, if you split the string Apples are tasty at spaces, it will return a list with the first item as Apples, the second item as are and the third as tasty.

[Charlotte_Loke]

Then why is the global Script empty? Also does the spaces in the list counted as one index?

[gordonlu310]

@Charlotte_Loke

Then why is the global Script empty?

Because BytesAvailableToReceive is 0, and that converted into text is an empty string.

@Charlotte_Loke

Also does the spaces in the list counted as one index?

Yes, global List has an empty text item, but that list still has a length of 1.

[Charlotte_Loke]

@gordonlu310

Because BytesAvailableToReceive is 0, and that converted into text is an empty string.

So should I set other number for the BytesAvailableToRecieve?
But I thought it is >0?

[gordonlu310]

@Charlotte_Loke

So should I set other number for the BytesAvailableToRecieve?

Yes, probably.

[Charlotte_Loke]

I have tried >1 or >2 but it still doesn't works

[gordonlu310]

I checked the description for that block.

It attempts to receive text from the Bluetooth, and if it returns empty text, it is probably an error (in your code).

[Charlotte_Loke]

So there is problem in my Arduino code?

[gordonlu310]

Maybe. That's all I know - I think a power user should know more than me.

[Charlotte_Loke]

ok thank you so much