How to drive a 3-wire SPI display?

[gaaf]

Hi,

I'm trying to drive an oled display in 3-wire SPI mode (no D/C line).

I initialize lcdgfx with DC pin set to -1. Display stays black no matter what I try.

#define VSPI_MOSI_PIN    2
#define VSPI_CLK_PIN    15
#define VSPI_CS_PIN     12
#define VSPI_DC_PIN     -1
#define VSPI_RST_PIN    -1

DisplaySSD1351_128x128x16_SPI display(VSPI_RST_PIN,{-1, VSPI_CS_PIN, VSPI_DC_PIN, 0, VSPI_CLK_PIN, VSPI_MOSI_PIN});

This oled is the only SPI device I have, so I have no way to verify if the problem is in the oled, lcdgfx or the platform. At least with 4-wire SPI the display is working fine.

Is 3-wire SPI supported by llcdgfx

(on the oled pcb, I've set the BS jumper to 1).