is it possible to convert a text to a list using APP Inventor ?

[Sebastian Rueda]

Hi to everyone.

I'm sending sharing serial information between my Android device and a micro-controlled device. In my protocol i use frames to send and receive this information. At this point i want to use a text box and a Button to complete the frames: 

I mean, the user writtes in the text box, when the button is pressed, this data is converted to a list, the checksum is computed for all the frame, the checksum is added to the list (frame) and through the use of "BluetoothClient1 - Send bytes" the list is sent.

i have been having several difficulties because i don´t know how to convert the string on the text box to a list of the decimal representation for each of the letters (it must be on decimar representation because that is the way my XOR function works) 

To clarify a little more. Lets say that the user wrote "TAG1" on the text box i want a list from that with the individial decimal representation:

List [1 ]= 84

List [2 ]= 65

List [3 ]= 71

List [4 ]= 1

The attached picture shows the same but with colors :P

Thanks in advance to everybody

Sebastián 

[SteveJG]

You want to do  convert the ascii character represented as Dec.  

App Inventor does not have a function to do that.  A simple way to convert would be to use two Lists as a conversion lookup table and then use the pairs block.to convert each character to dec.

 Here is a similar discussion in the forum.  https://groups.google.com/forum/#!topic/mitappinventortest/mQ5wxI1pF3Y   however the images in it are stale.

char       Dec

LIst1      List2

A           65

B           66

C           67

D           68

..

Z           90

0           48

1           49

2           50

..

9         57

  

Another way would be to use a Procedure like this perhaps

where the join blocks look like this  

0,1,2,3,4,5,6,7,8,9,

:,;,<,=,>,?,@,

A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z                The characterList is a List created from a simple csv text file (this is the join block)

You can convert the other way if you make the companion Procedure    DecToChar .

I am not sure where you go from here;  Is TAG1 supposed to be  8465711 ?   If so more work will be required to get this in the form you require.  You would probably 'read' each character separately using the red Text blocks, convert the character to a Dec value and save it to a checksum string ( the numerical string 8465711) and add that to a list of check sums that you want to save and perhaps print?     Or something else. ?

Regards,

Steve