ST7789 say nothing...

[giorgino]

excuse me, someone will become tired from my silly question but I'm going crazy...

After long time using LCD like 1306 (I2C) I was interested in the SPI family, as ST7789.
I connected this device but nothing appear

Spi configured as VSPI:
CLK: GPIO-18
MISO: GPIO-19
MOSI: GPIO-23
CS: GPIO-15
DC: GPIO-2
RES: GPIO-4

The display light on background lights on (I can fell the difference connecting BLK to GND)
but nothing appear, also using the direct command

Code: Select all

ST7789,txt,123

1209195: HTTP: st7789,txt,hello
1209264: static_file: /esp.css
1209265: Serve 304: 1688425635 /esp.css
1216874: Webserver 1 Arguments: 0: 'cmd' length: 14
1216875: HTTP: st7789,txt,123
1216937: static_file: /esp.css
1216938: Serve 304: 1688425635 /esp.css

I can read changes in the output:

CursorX:0
CursorY:205

so it seems to works, but the display doesnt show nothing.

Any ideas?

PS the displays are good, I've tested them with a direct Arduino sketch and they work

thank you in advance (as always)

[Ath]

- Did you configure the correct display model/pixels? There are some differences in initialization, causing some models not to work with wrong settings.
- Can you also connect the BLK to a GPIO pin, and set the brightness (should be 100% by default)?

[Ath]

I've just validated here with an ESP32 having a ST7789 135x240px display, updated to today's state of "mega" branch, and all is working as intended.

What TFT/graphics library did you use in your Arduino sketch?

[giorgino]

What TFT/graphics library did you use in your Arduino sketch?

It was the TFT espi

SOLVED:
My tft was a 240x240 without CS , I've bought another one from waveshare with more connection (CS too) and finally this works correctly

Perfect !

CS pin? I guess I need to study more about SPI protocol...

thank you
giorgio

[TD-er]

When using SPI, you have a few pins (clock, MISO, MOSI) for the data in and out (Master In Slave Out and the other direction)
And a CS pin for each device connected to this SPI bus.
CS is Chip Select, meaning you need to select which device you want to address.

So if you didn't have a CS pin on the display, you can only use that device on the SPI bus and nothing else as it will probably react to all SPI data being sent on that bus.

[Ath]

SOLVED:

Great!