MD240128A6W-FPTLW SPI 4W Support

[MarekOravec]

Hello guys, I have MD240128A6W-FPTLW 240x128 with ST7586S.

Is this display supported ? I tried every ST7586S library in u8g2 and not working...

My connection (I hope its good | for 3W/4W):
1 - Vdd
3 - Vss
4 - Display CS
5 - Display Reset pin
6 - Vdd
13 - A0 signal
14 - SPI MOSI
15 - Vdd
16 - SPI CLK
17 - LED+
18 - LED-

Thanks for advice :)

[olikraus]

Did you test one the following constructors:
U8G2_ST7586S_ERC240160_1_4W_HW_SPI
U8G2_ST7586S_YMC240160_1_4W_HW_SPI

Especially test this with the ContrastTest (page buffer) example, because you may need to adjust contrast (setContrast()) for your display.

Of course wiring might be also an issue: Which Board? How are wires connected? What are your arguments to the constructor?

[MarekOravec]

Hi, i have ESP32dev board with SW SPI. On the back of the pcb display I set the mod (with resistors) to 3W SPI. I dont have U8G2_ST7586S_YMC240160_1_4W_HW_SPI (Identifier is undefined) maybe bad library ? Im using VSC with PlatformIO. I also looked at the connections and they should all be fine (tested multiple times).. Now i dont have A0 signal connected (pin 13), i see some pixels rendered after init but nothing else. I'll try something and write to you how it turned out... Maybe i need reconfigure display info in u8x8_d_st7586s_erc240160.c for my display

[olikraus]

I think both driver should at least display something. 4W SPI should be more reliable. For testing indeed I suggest 4W Software emulated SPI.

[olikraus]

edited pixel_width = 240, pixel_height = 128

This will not fully work, because there is one more place to edit.

The font is stretched. The X and Y axes do not match the setting.

ST7586 displays are very complicated. I think in your case some reverse engineering is required to understand the layout / architecture of the display. Once this is known, we need to modify the data upload procedures:

u8g2/csrc/u8x8_d_st7586s_erc240160.c

Lines 186 to 210 in 5efba24

	// The ST7586S has an unusual 3 pixels per byte format the ERC240160 is even more annoying
	// as it has every 3rd COM line disconnected for extra oddness so here we read in a byte
	// (8 pixels) and pack that into 4 bytes of 2 pixels + 1 unused each. This has to be done
	// in a different order for flipped, normal UUx11x22 flipped 11x22xUU
	while (c > 0) {
	input = ((uint8_t)ptr[0]);
	for (i=0; i<4; i++)
	{
	byte = 0;
	if (u8x8->x_offset ==0){
	if (input & 0x80) // if bit 7
	byte = byte | 0x18; //set pixel 1
	if (input & 0x40) // if bit 6
	byte = byte | 0x3; //set pixel 2
	}
	if (u8x8->x_offset ==1){
	if (input & 0x80) // if bit 7
	byte = byte | 0xC0; //set pixel 1
	if (input & 0x40) // if bit 6
	byte = byte | 0x18; //set pixel 2
	}
	output[i] = byte;
	input <<= 2;
	}

Unfortunately, I am also not the author of this code, so the effort would be very hard for me to modify this.

Is there any detailed documentation/datasheet of your display?

[MarekOravec]

Hello, thanks for answer.
I have only these two datasheets: http://www.farnell.com/datasheets/3164273.pdf , https://www.buydisplay.com/download/ic/ST7586.pdf

[olikraus]

Hmm this doesn't really help :(

[MarekOravec]

Hello @olikraus, It works well 4W SPI with U8G2_ST7586S_S028HN118A_F_4W_SW_SPI. So problem solved :)

[olikraus]

:)