Lup Yuen Lee 李立源 @lupyuen@qoto.org

Let's render a Pink Screen when #NuttX boots ... To verify that the ST7789 Display Driver works

https://github.com/lupyuen/st7789-nuttx#render-pink-screen

#BL602 only talks SPI Mode 3 to ST7789 Display ... Wonder why 🤔

https://github.com/lupyuen/st7789-nuttx#spi-mode-3

Here's how we connect ST7789 Display to PineCone #BL602 @PINE64

https://github.com/lupyuen/st7789-nuttx#connect-bl602-to-st7789

Then we load the ST7789 Display Driver at #NuttX Startup

https://github.com/lupyuen/st7789-nuttx#load-st7789-driver

Here's how we load the #NuttX LCD Driver at startup

https://github.com/lupyuen/st7789-nuttx#load-st7789-driver

#NuttX wraps the ST7789 Display Driver as an LCD Device "/dev/lcd0" ... Which will be used by #LVGL Graphics Library

https://github.com/lupyuen/st7789-nuttx#configure-nuttx

We'll use the ST7789 Display Driver that comes with Apache #NuttX RTOS ... Batteries all included! 🔋

https://github.com/lupyuen/st7789-nuttx#configure-nuttx

#RISCV #BL602 with ST7789 Display and #LVGL Graphics ... Let's make it work on Apache #NuttX RTOS!

https://github.com/lupyuen/st7789-nuttx

And that's how we flip the ST7789 Data / Command Pin ... Inside the SPI Driver for #BL602 #NuttX!

https://github.com/lupyuen/incubator-nuttx/pull/44

Tested the ST7789 Data / Command Pin with a Logic Analyser ... Yep it works on #BL602 #NuttX! 🎉

https://github.com/lupyuen/incubator-nuttx/pull/44

After every ST7789 SPI Transfer on #BL602 #NuttX, we revert MISO from GPIO Pin back to SPI Pin ... In case other drivers need MISO

https://github.com/lupyuen/incubator-nuttx/blob/st7789/arch/risc-v/src/bl602/bl602_spi.c#L414-L454

To flip the ST7789 Data / Command Pin on #BL602 #NuttX: We reconfigure SPI MISO as a GPIO Pin ... On the fly!

https://github.com/lupyuen/incubator-nuttx/blob/st7789/arch/risc-v/src/bl602/bl602_spi.c#L678-L731

SPI Driver for #ESP32 #NuttX flips the ST7789 Data / Command Pin as though it was GPIO ... But actually the pin is designated as SPI MISO ... Let's do the same for BL602

https://github.com/apache/incubator-nuttx/blob/master/boards/risc-v/esp32c3/esp32c3-devkit/src/esp32c3_board_spi.c#L64-L84

Making strange changes to #BL602 #NuttX SPI Driver ... Hope this works for ST7789 Display 🙏

https://github.com/lupyuen/incubator-nuttx/blob/st7789/arch/risc-v/src/bl602/bl602_spi.c#L678-L729

ST7789 Display with PineCone #BL602 @PINE64 on Apache #NuttX RTOS ... Coming up next!

Here's the SPI Problem on #BL602 #NuttX: SPI Poll Exchange works OK ... But if we call SPI Poll Send (instead of Poll Exchange), the SPI Port is not configured ... And the function hangs!

I'll submit this PR to NuttX soon https://github.com/lupyuen/incubator-nuttx/pull/42

#BL602 #NuttX SPI Driver has a glaringly obvious bug ... Can you spot it? 🤔

Hint: Both SPI Functions are exposed to NuttX Apps

https://github.com/apache/incubator-nuttx/blob/master/arch/risc-v/src/bl602/bl602_spi.c#L763-L930

Here's how we write an I2C Register with #RustLang on Apache #NuttX RTOS

https://lupyuen.github.io/articles/rusti2c?8#write-i2c-register

Reading an I2C Register with #RustLang on Apache #NuttX RTOS

https://lupyuen.github.io/articles/rusti2c?7#read-i2c-register

What's inside the #RustLang Embedded HAL for Apache #NuttX RTOS

https://lupyuen.github.io/articles/rusti2c?6#nuttx-embedded-hal