A very interesting issue about board autodetect

[Yixi]

Yesterday, after my three-year-old son dropped my Cardputer, I restarted it and found that the screen display was abnormal, with some black areas and some garbled sections.

At first, I thought the screen was damaged from the drop, but when I flashed other firmware, like M5Launcher, the screen displayed normally. Only the code I compiled based on M5Cardputer.h shows the abnormal display.

At this point, I began to suspect it was a screen configuration issue. So, I used the code Serial.printf("width:%d, height:%d\n", M5Cardputer.Display.width(), M5Cardputer.Display.height()); to print out the information, and found that both the screen width and height were 240.

However, I couldn’t find a place in M5GFX to manually configure the display settings. After extensive debugging, I discovered that during M5GFX’s autodetect process, the board was being identified as board_t::board_M5VAMeter.

The reason was that after I dropped the Cardputer, the value obtained in result at this point was 1.

M5GFX/src/M5GFX.cpp

Lines 1475 to 1486 in ff11e09

	auto result = lgfx::gpio::command(
	(const uint8_t[]) {
	lgfx::gpio::command_mode_input_pulldown, GPIO_NUM_44, // Cardputer = IrDA_TXD
	lgfx::gpio::command_mode_input_pullup , GPIO_NUM_44,
	lgfx::gpio::command_read , GPIO_NUM_44,
	lgfx::gpio::command_end
	}
	);
	for (auto &bup : backup_pins) { bup.restore(); }
	// In "Cardputer", even if GPIO44 are set to Input_pullup, LOW is output.
	// This characteristic can be used to distinguish between the two models.
	board = (result == 0) ? board_t::board_M5Cardputer : board_t::board_M5VAMeter;

I modified the code locally and after recompiling, the screen displayed normally.

This thing is so amazing...

So, is there a way for us to manually specify the board model and skip the autodetect logic?

[lovyan03]

Hello @Yixi .

I think the IrDA LED was probably damaged by the impact of the fall. Since the M5GFX determines the model under the assumption that the hardware is not broken, it seems that it was no longer able to properly identify the model.
Currently, there is no way to disable automatic identification. I apologize for not being able to offer a solution right now.
I would like to consider some kind of countermeasure in the future.