Ravenscar_Full: plan to support Text_Float_IO

[LaetitiaEl]

Hi, Do you have a plan to support the Text_Float_IO (a-tiflio library) in the ravenscar_full? My need is to convert a Float to a String to send it via UART for telemetry/debug purpose.

Will it work if I add the following files to the bb-runtimes : (Ada_Drivers_Library/boards/stm32f746_discovery/src/full/) for test and build the board using gprbuild/gprinstall :

• a-flteio : for Ada.Float_Text_IO
• a-tiflio : for Ada.Text_IO.Float_IO
• a-wtflau : for Ada_Text_IO.Float_Aux
• a-wtgeau
• i-cstrea
• s-fileio
• s-ficobl
• s-param

Add the conditions (libs available in bb-runtimes) (how to add them):

• Add_Image_Float:yes to have s-imgrea (available in bb-runtimes) needed by: a-wtgeau
• Add_Value_Float:yes to have s-valrea (available in bb-runtimes) needed by : a-wtgeau
• Add_Streams:yes to have a-stream (available in bb-runtimes) needed by : s-ficobl

Thank you in advance,

[Fabien-Chouteau]

Hello @LaetitiaEl,

Do you have a plan to support the Text_Float_IO (a-tiflio library) in the ravenscar_full?

Which package goes in what run-time, is what we call the run-time profile. There are 3 profiles for the bare metal embedded run-times: ZFP, Ravenscar SFP, Ravenscar Full.

We don't have plans to add those packages in the Ravenscar Full proile.

My need is to convert a Float to a String to send it via UART for telemetry/debug purpose.

You should be able to do 'Img on float types, this will convert the float to String. However you don't have control on the representation.

A solution that I used once was to convert to a fixed point type, and then use 'Img:

with Ada.Text_IO; use Ada.Text_IO;
procedure Learn is
   type Fixed_Type_1 is delta 0.00001 digits 18;
   type Fixed_Type_2 is delta 0.001 digits 18;
begin
   Put_Line (Float (123456789.123456789)'Img);
   Put_Line (Fixed_Type_1 (123456789.123456789)'Img);
   Put_Line (Fixed_Type_2 (123456789.123456789)'Img);
end Learn;

Output:

1.23457E+08
123456789.12345
123456789.123

Will it work if I add the following files to the bb-runtimes : (Ada_Drivers_Library/boards/stm32f746_discovery/src/full/) for test and build the board using gprbuild/gprinstall :

It will work, but it will mean that you are the only one capable of compiling your application. Because it will depend on a non standard run-time profile.

Thank you in advance,

You are welcome,

[LaetitiaEl]

@Fabien-Chouteau I noticed that the Ada.Text_IO (a-textio) is not the same as the standard one. That's why ti will be pointless from my side to move in that direction.

Thank you for the code example, I'll try it. Do you have an example how to how to link the Ada.Text_IO.Put_Line to a UART?

[LaetitiaEl]

The example works very fine in the STM32F746 Nucleo! I managed to send the data like following (not proper way) to test:

  for ch of FixedFloat(AccelRates(X))'Img loop
         c := Character(ch);
         data_1B(0) := Character'Pos(c);
         UART_OUT.Transmit(data_1B,status);
      end loop;

[Fabien-Chouteau]

Do you have an example how to how to link the Ada.Text_IO.Put_Line to a UART?

It would require a modification of the run-time, and there is no real advantage to do that in your case.