Displaying Data to TouchGFX UI using wildcards

[Nikola-01]

Hi Guys

I am a noobie and I am just starting out with TouchGFX. I have designed a 7 screen gui which cycles between screens (1-7 in that order which cylces indefinitely) and I have a text area which I want to populate with real-time data. This is only on screen 4 and 6 and I have defined the wildcards in the designer as follows:

I have generated the code using TouchGFX 4.23.2 and then I open the IOC file in CubeMX where I add ADC initialization as well as two tasks and two semaphores. One to update screen4 and one to update screen6, I then generate the code in MX and then click on "Open Project" to import it into CubeIDE.

I do not know where to take it from here. Essentially I want to read an ADC voltage (polling) in the two tasks I have created, then from there update screen4 and screen6 wildcards when the screen is loaded.

Here is my main.c:

I have tried to follow this video: https://www.youtube.com/watch?v=EbWOv_0Lp-U&t=241s, however when I adapt it to 7 screens and 2 semaphores and tasks, I upload the code to my STM32F429i-DISC1 and I just observe a white screen, however when I upload the code without having made any modifications in STMCubeIDE as seen in the video, I see the desired gui implemented with the exception of the real time data being displayed on screen 4 and 6.

Any help would be appreciated thanks.

[Nikola-01]

Ok, so I have worked on it longer and I have gotten to this point:
I call a function in my Screen6View.cpp which I want to update the wildcard value in the gui.
This is how my code looks:

#include <gui/screen6_screen/Screen6View.hpp>
#include "string.h"

Screen6View::Screen6View()
{

}

void Screen6View::setupScreen()
{
    Screen6ViewBase::setupScreen();
}

void Screen6View::tearDownScreen()
{
    Screen6ViewBase::tearDownScreen();
}

void Screen6View::UpdateCurrent(float value)
{
	Unicode::UnicodeChar buffer[6];
    Unicode::snprintfFloat(buffer,sizeof(buffer), "%.2f", 3.15345);
	textAreaCurrent.setWildcard(buffer);
	textAreaCurrent.invalidate();
}

When I debug my board, I can see that I am entering the UpdateCurrent function. I set the Initial value of the wildcard to be -1 and ass soon as I call my UpdateCurrent function the wildcard updates to the fallback character of the wildcard which I set to be '-' in touchGFX.

When I inspect the contents of buffer during runtime I see the following:
buffer[0] = 51
buffer[1] = 46
buffer[2] = 49

buffer[3] = 53

buffer[4] = 0

buffer[5] = 42405

I know buffer[0]-buffer[4] is supposed to represent 3.15 with null termination.

I just don't know why the embedded gui is updating the wildcard with the fallback character '-'.

[Nikola-01 · Accepted solution]

This is The code which I found works in case anyone was wondering.

void Screen4View::UpdateVoltage(float value)
{
	Unicode::snprintfFloat(textAreaVoltageBuffer,sizeof(textAreaVoltageBuffer), "%.2f V", value);
    textAreaVoltage.invalidate();
}

[BMB]

I have found out (v4.23.1) that Unicode::snprintf will not properly translate char into Unicode in certain formats.

For example the code below will just copy the chars as bytes into the target buffer with no remapping from ASCI to Unicode:

char const * const pverstr = presenter->p_version_string_get();

Unicode::snprintf(txt_SoftwareVersionValueBuffer, sizeof(txt_SoftwareVersionValueBuffer),

"%s", pverstr);

But the following will work properly:

Unicode::strncpy(txt_SoftwareVersionValueBuffer, pverstr,

sizeof(txt_SoftwareVersionValueBuffer));