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notro / fbtft

Linux Framebuffer drivers for small TFT LCD display modules. Development has moved to https://git.kernel.org/cgit/linux/kernel/git/gregkh/staging.git/tree/drivers/staging/fbtft?h=staging-testing
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Pi Zero and freetronicsoled128 #382

Closed multivac61 closed 7 years ago

multivac61 commented 8 years ago

I´m having issues using the SPI bus with fbtft on my Pi Zero to control the Freetronics OLED display. I followed the tutorial from here without the old kernel update trick etc.

When looking at both the MOSI and SCLK signals coming from the Zero I can see that they are both very distorted when running FRAMEBUFFER=/dev/fb1 startx. When I however run the SPI test code from here I get much cleaner signals.

Could the issue be related to the drivers?

notro commented 8 years ago

Try lowering the speed (default 20MHz): sudo modprobe fbtft_device name=freetronicsoled128 speed=8000000 The spidev test code runs at 500kHz.

multivac61 commented 8 years ago

Of course the distorted waveform had something to do with the SPI speed! Now I am able to update the screen flawlessly at 15MHz from the Pi zero. Thanks @notro!