ST7796 4" TFT Touchscreen problem ?
Posted: Sat Aug 14, 2021 6:41 pm
Does anybody have a 4" TFT Touchscreen working correctly ?
I have two 4" TFT Touchscreen displays, which I think are ST7796, but the only markings I can see are 4.0" TFT SPI 480x320 V.10
They are pin compatible with the smaller ILI9341 displays (with the first 5 pins of the main group labelled as "touch"), and they both display correctly with Annex32 WiFi BLE CAN 1.43.5 configured for ST7796.
But the touchscreens don't calibrate correctly.
When running touch.calib, the first green cross displays at the top left, but neither of the modules will register a touch on that mark, nor anywhere else on that side of the display, whereas a touch to the opposite side may register.
So the modules display correctly, and can register touch, but not in the correct locations.
Because both 4" modules have the same problem, and ILI9341 modules behave correctly, it suggests there may be an ST7796 driver problem... unless someone is actually using a 4" ST7796 without any problems ?
I have two 4" TFT Touchscreen displays, which I think are ST7796, but the only markings I can see are 4.0" TFT SPI 480x320 V.10
They are pin compatible with the smaller ILI9341 displays (with the first 5 pins of the main group labelled as "touch"), and they both display correctly with Annex32 WiFi BLE CAN 1.43.5 configured for ST7796.
But the touchscreens don't calibrate correctly.
When running touch.calib, the first green cross displays at the top left, but neither of the modules will register a touch on that mark, nor anywhere else on that side of the display, whereas a touch to the opposite side may register.
So the modules display correctly, and can register touch, but not in the correct locations.
Because both 4" modules have the same problem, and ILI9341 modules behave correctly, it suggests there may be an ST7796 driver problem... unless someone is actually using a 4" ST7796 without any problems ?