Giga Display Shield: Display.begin() fails with H7_Video, but works with GFX (Mbed OS Core issue?)

Official Hardware Mega GIGA R1 WiFi
1

Hello,

I am experiencing a severe initialization issue with the Giga Display Shield (480x800) on an Arduino Giga R1. I suspect a bug within the current Arduino Mbed OS Core/Arduino_H7_Video library implementation.

1. The Setup

  • Board: Arduino Giga R1
  • Shield: Giga Display Shield (480x800)
  • Core: Arduino Mbed OS Boards (newly reinstalled, latest version)
  • Goal: Use LVGL, which requires the Arduino_H7_Video library.

2. The Problem (H7_Video Fails)

The minimal sketch using the hardware-accelerated H7 video driver consistently fails at initialization:

#include "Arduino_H7_Video.h"
#include "Arduino_GigaDisplayTouch.h"

Arduino_H7_Video Display(800, 480, GigaDisplayShield);
Arduino_GigaDisplayTouch Touch;

void setup() {
  Serial.begin(9600);
  delay(2000); 
  // Added an aggressive 1000ms delay before begin() - still fails
  delay(1000); 

  if (!Display.begin()) {
    Serial.println("!!! Display Error - H7_Video FAILED !!!"); 
    while(1); 
  }
  Touch.begin();
  Serial.println("H7 Display successful."); // Never reached
}
void loop() {}

Result: !!! Display Error - H7_Video FAILED !!! is printed.

3. The Crucial Finding (GFX Works)

To rule out a hardware defect, I tested the display using the simpler GFX library. This test succeeds without issue, proving the display panel, wiring, and power supply are all functional.

Library used: Arduino_GigaDisplay_GFX.h
Result:** Benchmark runs successfully, displaying graphics and text.

I have already performed a clean reinstallation of the 'Arduino Mbed OS Boards' package in the Board Manager to rule out a corrupted driver installation. The issue persists.

2

Hi!
Display.begin() returns 0 if everything goes fine, a number greater than 0 if an error occurs.
So, fix in this way:
if (Display.begin()) {

3

Oh, sorry, silly mistake! But I have one follow-up question.

I only created this code because the code in my project doesn't work anymore.

I use Square Line Studio for designing and programming the display.

Here is the important part of my Arduino code:

#include "Arduino_H7_Video.h"
#include "Arduino_GigaDisplayTouch.h"
extern "C" {
#include <kvstore.h>
#include "kvstore_global_api.h"
}
#include <Wire.h>
#include <Adafruit_MMA8451.h>
#include <Adafruit_Sensor.h>
#include "lvgl.h"
#include "ui.h"
#include "ui_helpers.h"
// Definition der State Machine
enum GameState {
  STATE_MENU,
  STATE_LIFE_MODE,
  STATE_TRAFFIC_MODE
};
GameState currentState = STATE_MENU; // Starte im Menü
Adafruit_MMA8451 mma = Adafruit_MMA8451();
// resolution 
Arduino_H7_Video Display(800, 480, GigaDisplayShield);
Arduino_GigaDisplayTouch Touch;

void setup() {
  delay(3000);
  Display.begin();
  Touch.begin();
  ui_init();
//...
kv_info_t info;
size_t actual_size;
//...
Wire.begin();
mma.begin()
//...
}
void loop() {
  lv_timer_handler();
//...
}

It should show a white screen, but this is what it shows instead. It's important to note that it was working on Wednesday.

unnamed
unnamed704×1000 193 KB

At first, I thought the display was damaged, but the demonstration test with the GFX library worked.

5

Have you recently update the mbed core from the board manager?

Last release should be the 4.4.1 (july 2024).

Try to rollback the core.