8 months ago.

Crash with resistive touchpad

Hi David,

I use TFT-8'' with resitive touchpad and after library update my old code (2016) crash. My investigation on constructor RA8875::RA8875 shows that pointer touchInfo is NULL. The pointer is used in TouchPanelReadable and with NULL my code crash. Does exist constructor RA8875 with memory alocation for touchInfo ? At the moment I allocate memory and change your library.

My code: TouchCode_t touch; point_t p;

lcd.init( 800, 480, 16,40, false, true); lcd.frequency(10000000); InitTS();

lcd.foreground( White ); while (1) { touch = lcd.TouchPanelReadable( &p ); if( touch != no_touch ) { lcd.printf( " \r" ); lcd.printf( "X=%d Y=%d C=%d\r\n", p.x, p.y, touch ); }; };

My change: JK_START touchInfo = (touchInfo_T *)malloc(FT5206_TOUCH_POINTS * sizeof(touchInfo_T)); JK_END

Best regards, Janusz

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8 months ago.

Hi Janusz,

This is quite embarrassing that I did not spot that (or test that combination after recent changes to support another touch controller). I have a couple of resistive touch displays in use, but haven't taken them out of service for an update after my last set of changes for the other touch controllers.

I reviewed your proposal, which is nearly what I implemented. The change was basically as you suggested, in the constructor used for the resistive touch. However, the resistive supports only a single touch, so the # touch points can be 1. I created a #define for that, to be consistent with the other touch controllers, and so that also affected two other files.

I just published an update to the library (as revision 176). I'm hoping you will spot this note, give it a go, and follow up here indicating success/failure.

Hi David,

update works fine, thanks a lot

posted by Janusz Klimczak 24 Mar 2019

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