Error 515 and other questions

Will it be Okay to post whole .aia file of the project?? I am not familiar with backpack yet.. Thanks..eBike_1v03.aia (56.4 KB)

Got it. I understand..

...........Any luck?

Not yet. Please download my project .aia and review/comment. As I am a novice, I don't have the analysis capability.. This is my first trial and there should be many mistakes even though I was able to get up to 6 variables. The problem, List index too large happens with 7th variables.


I need the Script too - can't fix comms with only one end of the string :upside_down_face:

What do you mean by script?? Is it Arduino code?? Re the app, I sent project .aia..

BT_1V3_ino.txt (4.9 KB)

...Taking a dinner break, get back to you later this evening (UK time)

What do you get if you disable Labels (2, 5, 8 ... 17) and put a
Label2.Text = input

OK.. Thanks.. I've been in UK many times when I was working for IBM. I visited IBM Hursley and Greenock.

I worked at IBM Hursley for four years back in the 90's :wink:

What is this, confession time? :joy:

Better than working for Morecambe and Wise... that nearly happened too :wink:

I'm not sure about that - did you see the documentary about Eric, with his home movies of the family etc? Probably would have been fun to work with those two.

BT_1V3_inoEdit.txt (5.2 KB)

Comments within the file.

Do you really need to send a value to Arduino before receiving values?

Edit: If so, use a seperate Clock Timer for that event, then that Timer can call the Data-Receive timer. App Inventor Blocks that have the blue symbol top left can be expanded with a left-click - e.g. an If Block can be expanded to If-then-else if-else etc.

There's too much wrong in your Project for me to correct, so I'm attaching a basic setup that you can expand. Your global list should be initialized as a List (not a dictionary). Your timer is set in Properties - set it in Blocks as per my example. Note, your timer is @ 1000 millis, but the data is being sent every 200 millis! Sending and displaying the data faster than every 4 to 5 seconds is pointless - the human eye cannot follow a screen updating that fast.

BT_Basic_Setup.aia (8.4 KB)

Dear Chris,

Thanks for your advice and now I can get 7 variables without any problem. The App sends a request to Arduino in every 1 sec asking for variables. Then the Arduino sends variables when it receives a request from the App.

eBike_1v01.aia (57.2 KB)

See my .aia as attached. I reset Version to 1V01 and so please don't be confused. Any comments will be appreciated.



Very pleased to meet you. Hursley lab in Winchester was a very nice place to visit. I still remember the Cathedral.


Strangely, there seems to be a number of posts missing from this topic.