TM4C1294NCPDT: Touch-Screen interface with tiva TM4C1294ncpdt

Jackson Chinelli

Part Number: TM4C1294NCPDT
Other Parts Discussed in Thread: EK-TM4C1294XL

I'm trying to interface a 4 wire resistive touch screen with Tiva TM4C1294 launchpad, I'm a beginner and I'm having a problem like this:

I configurated the ADC to do the readings of the x and y axis, but when there is no touch at the screen the ADC continues to show a conversion number around 2500-2600.

how can I eliminate this value and show only when the touchscreen is really being touched?

Thanks.

over 6 years ago

0 Bob Crosby over 6 years ago

TI__Guru 72500 points

First, I suggest you measure the voltage at the ADC input pin and verify that your hardware is providing the voltage you expect. It must be in the range of 0.0V to 3.3V. Here is a working project that you can run on an EK-TM4C1294XL launchpad that reads a voltage on AIN0 and prints the converted number out UART0. You can see the results in the terminal emulator of Code Composer Studio. Use the CCS "file" -> "import" function to grab this project from the .zip file and add it to your workspace.

/cfs-file/__key/communityserver-discussions-components-files/908/ADC_5F00_single_5F00_ended.zip

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TM4C1294NCPDT: Touch-Screen interface with tiva TM4C1294ncpdt