Lup Yuen Lee 李立源 @lupyuen@qoto.org

How our #NuttX App reads the touched coordinates from #PineDio Stack's Touch Panel

https://lupyuen.github.io/articles/touch?6#read-touch-data

Apache #NuttX RTOS defines a standard data format for Touch Data

https://lupyuen.github.io/articles/touch?5#touch-data

What's inside a #NuttX Touchscreen Driver

https://lupyuen.github.io/articles/touch?4#nuttx-touchscreen-drivers

Connecting #PineDio Stack's CST816S Touch Panel to Apache #NuttX RTOS

https://lupyuen.github.io/articles/touch?3#cst816s-pins

#PineDio Stack's CST816S Touch Panel seems elusive ... Thanks to PineTime we know everything now!

https://lupyuen.github.io/articles/touch?2#cst816s-touch-panel

Building the Touch Panel Driver for Apache #NuttX RTOS on #PineDio Stack #BL604 @PINE64 ... All shall be explained in this article

https://lupyuen.github.io/articles/touch?1

50 articles in the "The #RISCV #BL602 & BL604 Book" 🎉 ... Let's hit a hundred! 👍

https://lupyuen.github.io/articles/book

Apache #NuttX RTOS on #PineDio Stack #BL604 now supports Touch Screen ... Works OK with LoRaWAN too! 👍

https://github.com/lupyuen/incubator-nuttx/pull/59

Upcoming fixes for Apache #NuttX RTOS on #PineDio Stack #BL604 🤔

https://github.com/lupyuen/cst816s-nuttx#i2c-logging

Our #NuttX Driver for #PineDio Stack Touch Panel won't return any valid Touch Data unless we enable I2C Logging ... Could be an I2C Timing Issue or Race Condition 🤔

https://github.com/lupyuen/cst816s-nuttx#i2c-logging

But for Touch Up Events the Touch Coordinates are invalid ... Our #PineDio Stack driver patches the Touch Coordinates with the data from the last Touch Down Event

https://github.com/lupyuen/cst816s-nuttx#touch-up-event

Touch Coordinates read over I2C from #PineDio Stack Touch Panel ... Are returned unchanged to the LVGL Test App as a #NuttX Touch Down Event

https://github.com/lupyuen/cst816s-nuttx#touch-down-event

LVGL Test App calls read() repeatedly on #PineDio Stack's Touch Panel Driver to get Touch Data ... But it should call poll() instead to block on Touch Data 🤔

https://github.com/lupyuen/cst816s-nuttx#read-touch-data-1

#NuttX Driver for #PineDio Stack #BL602's Touch Panel responds correctly to touch! 🎉 The touched coordinates are rotated sideways ... But we can fix that later in the ST7789 Display

https://github.com/lupyuen/cst816s-nuttx#screen-is-sideways

Our #NuttX Driver for #PineDio Stack's Touch Panel returns 4 possible states: Touch Down vs Touch Up, Valid vs Invalid

https://github.com/lupyuen/cst816s-nuttx#read-touch-data

Here's how our #NuttX Driver reads the Touch Data on #PineDio Stack #BL604

https://github.com/lupyuen/cst816s-nuttx#read-touch-data

Apache #NuttX RTOS has a standard data format for Touch Input ... Let's implement this for #PineDio Stack #BL604

https://github.com/lupyuen/cst816s-nuttx#touch-data

Tapping the screen on #PineDio Stack #BL604 ... Correctly triggers a GPIO Interrupt on #NuttX RTOS! 🎉

https://github.com/lupyuen/cst816s-nuttx#test-gpio-interrupt

#PineDio Stack's Touch Panel triggers a GPIO Interrupt when we tap the screen ... Here's how we handle the GPIO Interrupt in #NuttX

https://github.com/lupyuen/cst816s-nuttx#gpio-interrupt

xkcd: Weird Unicode Math Symbols (and their meanings)

https://m.xkcd.com/2606/