[Solved] FT811 with Goodix GT911 capacitive touchscreen not working

[atharvalele]

Hello,

I have a FT811 connected to a LCD which has a Goodix GT911 touch controller.

I have connected the hardware as shown in AN336, section 6.6.2 : https://brtchip.com/wp-content/uploads/Support/Documentation/Application_Notes/ICs/EVE/AN_336_FT8xx-Selecting-an-LCD-Display.pdf

Except that instead of using one of FT811's GPIOs, I used a GPIO from my microcontroller (PIC24FJ1024GB610). The initialization sequence is exact same as told in the PDF.

I am writing the TOUCH_U8 array into RAM_CMD, setting REG_CMD_WRITE to TOUCH_DATA_LEN and then waiting in a while() loop until the execution of the commands is complete.

However, I am not able to get touch input working. Neither in calibration mode nor in normal mode. Reading REG_CTOUCH_RAW_XY and REG_CTOUCH_SCREEN_XY always results in 0x8000 for the X&Y values.

Any suggestions / example code would be highly appreciated.

Hoping someone can help.

Thank you.

[atharvalele]

Update: Issue Solved

It was due to a bodgie connection for the GPIO  pulldown resistor. We were using our FT810 boards for testing the chip and had hacked on the needed stuff.

Thank you!