thanks for the reply

The LCD is wired to the Raspberry Pi’s GPIO pins, while the HDMI port of the Pi still works when connecting to a monitor. The outputs are mirrored, what you see on the LCD matches what you see on the HDMI output.

Hi Vinod, I’ve only tested this on Raspbian on a Pi4, other variants I’ve not tried.

Patrick,

I do hope somebody on here has run across this and can give some guidance. I unfortunately can’t do much at the moment as I’m swamped with a large work project – but I do hope you’re able to get it resolved, and if you do, please drop a line and let me know! Good luck!

The previous message (refering to PICO) gave me nothing better on Rasp PI 4b.
I tried to swap orange et green wires: useless. Still the backlight on with no image on screen.

The Picomori Pico Display goes like the following list:

Picomori RaspPico
33.AGND — 33. AGND
32.ADC1 — 32.GPIO27_ADC1
31.ADC0 — 31.GPIO26_ADC2
30.RESET — 30. RUN
26.BL_EN — 26.GPIO20
25.MOSI — 25.GPIO19
24.SCK — 24.GPIO18
23.GND — 23.GND
22.CS — 22.GPIO17
21.DC — 21.GPIO16

I’ll try (down) and let you know
Picomori — RaspPico
30.RESET — 30. RUN
26.BL_EN —26.GPIO20
25.MOSI —25.GPIO19
24.SCK —24.GPIO18
23.GND —23.GND
22.CS —22.GPIO17
21.DC —21.GPIO16

Hello all,

big big thanks to you, Eric for all that.

According to https://github.com/juj/fbcp-ili9341/issues/125 (link given by Eric bellow), I desactivated all references to « ALL_TASKS_SHOULD_DMA ».

On top of that, I compilated the prog with the -DUSE_DMA_TRANSFERT=OFF option (as suggested on compilation screen).

Still: same result; only backlight is on.

Meanwhile, on HDMI screen, the display seams to be recognized as it says:
"Source GPU display is 768x1360. Output SPI display is 240x240 with a drawable area of 240x240. Applying scaling factor ....
scaleWidth: 240, scaleHeight: 240"

So ... I'm back questionning the pinout.

I encounter the same issue: only backlight on, running fbcp-ili9341 on RaspPI-4B.
Meanwhile, I have to say that my display is a 240×240 on which the pins are like this:
GND, VCC, SCK, SDA, RES (¿reset?), DC (¿dataControl?), BLK (backlight).
My pinout goes like this:
SI7789- wire color – RaspPi PIN
GND – NOIR       – 20.GND
VCC – BLANC    – 17.VCC
SCK – VIOLET   – 23.SCLK
SDA – BLEU       – 19.MOSI
RES – VERT       – 22.GPIO 25
DC  – JAUNE    – 18.GPIO 24
BLK – ORANGE   – 24.CEO

Am I doing something wrong on pinout ?