Bitwise Construction of a byte in telemetry screen using CHECKBUTTON

[jurgensymynck]

Hello,

Being a novice Ruby user, I want to construct a byte value in a telemetry screen, that will be sent to a register in a microcontroller, using checkbuttons. I don't seem to find the correct syntax, however. Below is a representation of the desired screen (only a nibble for brevity):

Register Builder

• BIT ZERO
• BIT ONE
• BIT TWO
• BIT THREE
  [0x02]
  [ Send ]

This is what I 've come up so far:

VERTICALBOX "Register Builder"
    NAMED_WIDGET REG_BIT_0 CHECKBUTTON 'BIT ZERO' UNCHECKED
    NAMED_WIDGET REG_BIT_1 CHECKBUTTON 'BIT ONE' CHECKED
    NAMED_WIDGET REG_BIT_2 CHECKBUTTON 'BIT TWO' UNCHECKED
    NAMED_WIDGET REG_BIT_3 CHECKBUTTON 'BIT THREE' UNCHECKED
    <%= register_value = 0x00 %>
    NAMED_WIDGET REGISTER textfield 12 <%= register_value %>
    <% if get_named_widget("REG_BIT_0").checked? then register_value += 1 end %>
    <% if get_named_widget("REG_BIT_1").checked? then register_value += 2 end %>
    <% if get_named_widget("REG_BIT_2").checked? then register_value += 4 end %>
    <% if get_named_widget("REG_BIT_3").checked? then register_value += 8 end %>
    BUTTON 'Send' 'cmd("MYTARGET CMD_SET_REGISTER with REGISTER <%= register_value %>")'
END

This results in error:

ERB error at C:/COSMOS/LORERobot/config/targets/LOREROBOT/screens/Register.txt:8
undefined method `get_named_widget' for #<Cosmos::ConfigParser:0x0000000004475f00>

Can anyone put me on the right track?

[ghost]

Most of your code here is running in ERB (the code in <% %>). That is run as part of the screen config file, not when the button is pressed. You should move all that code into button code before the cmd(). Seperate lines with semicolons.

[ghost]

The COSMOS demo has an example in commanding.txt

[jurgensymynck]

Thanks a lot, that was the tip i needed! Below is the working code, and a screenshot of the screen. I should probably move the button code to a separate file as suggested in the documentation.

Note the commented-out line where i (unsuccesfully) tried to display the ultimate register_value (hinted at in the screenshot image). Is there a way to extract this value from the button code? I guess I could have the microcontroller return the REGISTER nibble in a telemetry item upon sending the command, but that seems overkill... Any pointers are greatly appreciated!

SCREEN AUTO AUTO 0.2
VERTICALBOX "Register Builder"
    NAMED_WIDGET REG_BIT_0 CHECKBUTTON 'BIT ZERO' UNCHECKED
    NAMED_WIDGET REG_BIT_1 CHECKBUTTON 'BIT ONE' CHECKED
    NAMED_WIDGET REG_BIT_2 CHECKBUTTON 'BIT TWO' UNCHECKED
    NAMED_WIDGET REG_BIT_3 CHECKBUTTON 'BIT THREE' UNCHECKED 
    # LABELVALUE LOCAL LOCAL register_value
    BUTTON 'Send' 'register_value = 0x00; if get_named_widget("REG_BIT_0").checked? then register_value += 1 end; if get_named_widget("REG_BIT_1").checked? then register_value += 2 end;if get_named_widget("REG_BIT_2").checked? then register_value += 4 end; if get_named_widget("REG_BIT_3").checked? then register_value += 8 end; cmd("MYTARGET CMD_SET_REGISTER with REGISTER #{register_value}")'
END