Cannot find the way to extract raw data of GT911 touchscreen

LinuxBEST

LinuxBEST

New member
Is there a method to extract raw data from a touch screen using the GT911, regardless of the type of Raspberry Pi board used? (using I2C) By raw data, I don't mean the simply recognized touch coordinates, but rather the raw data of the touch values (capacitive values) detected on each of the 26x14 = 364 touch grids. If this is too difficult, does anyone have information on the 7-bit addresses referred by each touch grid? This is my first time extracting raw data from a touch screen, so I appreciate your understanding of these basic questions. I found datasheet or the programming guide, and searched all over the internet, but I couldn't find it, which is why I'm asking you. Also, I contacted to Goodix support, but Goodix support team no longer responds to inquiries related to touchscreens. There appear to be many people who have already asked about the complete datasheet for the GT911 with questions similar to mine, but they all seem to have received unhelpful answers. (https://developers.goodix.com/en/search ... /true/10/1) Pretty please, I wish you to help me. Sincerely, thank you.
Crystalfontz LCD Blog
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.
 
LinuxBEST

LinuxBEST

New member
CF Kelsey said:
Here is the datasheet: https://www.crystalfontz.com/controllers/datasheet-viewer.php?id=464

Here is the programming guide: https://www.crystalfontz.com/controllers/datasheet-viewer.php?id=478

If you let me know which of our displays you're using, I can point you to the demo code where we implement the touch
Click to expand...
What I meant is that we have already found the datasheet and programming guide, but we haven't found how to extract the raw data from the touchscreen among them. For example, in the case of FT company's touchscreen, they disclose all the register addresses related to test mode, enabling the extraction of raw data from the touchscreen. However, GT company's touchscreen does not seem to disclose the register addresses related to test mode separately. We want to know the register address where the capacitance value measured by each grid of the touchscreen in test mode is stored.
 
CF Tech

CF Tech

Administrator
Some companies disclose more information than others. Unless you are able to find some Goodix test documentation that exposes the raw data registers then that information is probably not practically* available.

There are a bunch of registers in the GT911 Programming guide. None of those give you what you are after?

* You could try some reverse engineering by reading around in the register space -- difficult and tedious at best. Even if successful you run the risk that the next rev of the chip will invalidate that work.

I poked around a bit, but the only thing I found close is your post over on the Raspberry Pi forum. The internet version of the circle of life.

Stepping back a bit . . . what is the end result of what you want to do? Certainly reading the registers is an intermediate step . . . what is the top level goal of your project?
 
Last edited:
You must log in or register to reply here.
Top