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Resistive Touch Panel Information

Hello,

I am looking at using the DT043BTFT-TS for a new prototype that I am working on.  I am trying to find out information with regards to the resistive touch function of this device.  I didn't see anywhere in the documentation it discussed the resistive touch.  Do you have any additional information regarding this feature?

Thank you,

Gary

Replies

engineering_seacomp's picture
engineering_seacomp
January 29, 2020

Hi Gary,

Resistive touch screen technology has been around for decades, and is very well documented via our friend Google. 

There are 2 ways to interface to a resistive touch screen.

1) Interfaced to a microcontroller directly with 4 pins (2 analogs, 2 digital)

2) or use a digitizer such as Microchip AR1021

Calibration is required with all resistive touch, but it's pretty simple.

Here are some hints on how to implement.

Please see:

https://www.dropbox.com/s/6jv2nh0g401r2b4/MAX11802_TouchScreen_Calibration_AN5296.pdf?dl=0

The calibration is really about displaying a dot on the screen at a particular location  (X,Y), then measuring the reported value (Cx,Cy) , then adjusting by that much (X'=X-Cx,Y'=Y-Cy).  With this method, you get accurate touches.  

Show a dot in each of the four quadrants at the factory as a one time calibration, and then store the values in NVM, forever.