Touch-Screen with Low-Level Language Programming

 

Duy-Ky Nguyen                                                                                                                                        2014-09-10

 

1. Introduction

This project is to investigate if a low-cost capacitive-touch LCD as a user interface @ $ 50

 

Capa_Touch_Screen

 

2. Tools

ATMega2560 using WinARM compiler


Arduino ATMega2560

 

3. References


Source of demo code 
BuyDisplay (Demo code using SPI bitbang for 8051)
http://www.buydisplay.com/default/5-inch-tft-lcd-module-800x480-display-w-controller-i2c-serial-spi

LCD Controller RA8875 (Demo code using parallel-bus for STM32

http://www.raio.com.tw/E%20version/e_product.8875.htm




4. Methodology

A true SPI code for ATMega2560 has been developed and worked a lot faster than 8051 as expected

Image created directly from the code

Geometry

Image read from SD card by name using FAT implemented in the code
Fuji

5. Conclusion

CTP-LCD

Top is : Id : X . Y
Touch the bar graph area to get Id (0 ~ 9) X (0 ~ 800) Y (0~480) to display the bar right at the touch point

Low-Level Programming for Touc-Screen looks more promising than Android