Time to publicate my bad experience with Calk-Elec. Since months I try to get a 7" black frame touch screen to rebuild my Carputer for the new car. A ready one with LCD 1280x800 I ordered before at AliExpress was not functional and misaligned, so and I sent it back and received my money back. Then I ordered a 7" black frame touch panel without LCD at Chalk-Elec. When I received it, I tried it without to remove the protection foil. I found that a part at right side aprox. 15mm is dead, no touches. On the usb connection board there is one green LED. The Led dims a little down when touches are occur. On the dead area the LED stays shiny. I tried it with other computers, 2 different Windows and my Linux Host. Always the same. OK, I thought, maybe the firmware on the board is not correct, so I searched on their web page for a last version. I flashed it to the board, but always the same.
Well, I sent an email to them and got in contact with Dr. Ace Jeangle. He sent me a new firmware file, I flashed it, the same. He sent me another 4 different firmware files. He explained that as I answered that on the back side of the fpc print, there is no serial number, they can't know what would be the correct firmware of it. Ha.
Ok, I flashed all of them with the same result. I asked if they would replace it with a working touch panel, no answer anymore. Note that I paid $60.49 for product and shipping and more VAT and Fedex fee €16.61.
Since I reported that none of the 4 firmware are working I don't get any answer from Dr. Ace Jeangle.
Then I tried a lot by myself. I ordered some 6pole fpc bread board. I tried to connect it directly to the I2C port of my C4 and compiled the kernel with GT911 touch module and needed to find a valid device tree setting. As I couldn't get it work I tried it with an Arduino Nano board. I found some library for it and ported it to ATMega328P. When I tried and tried, at the end I found that I connected it wrong. Now with correct connection I got touch events reporting to serial usb port. I found that there is always the dead zone on the right. There are no interrupts generated in this zone.
With the knowledge of right connection I got it also work with at I2C of the C4! But always the same. I read and learned and tried to download different configurations to the GT911. But nothing helped. I found also that after power cycle the configuration always resets to former configuration. I am in doubt that my flashed configuration is accepted by the chip.
The configuration I read out after power cycle doesn't match the connected pins.
As of the photo can be seen that channels 0 to 11 of sensors are connected, channels 12 and 13 not. Also the driver channels are not all connected, channel 0 to 10 and 12 to 22 are connected, 11, 22 and 23 are not.
I am pretty sure that the configuration is not right for it. I don't have the Goodix Tool to design a new configuration.
- photo_2023-05-18_14-00-20.jpg (249.41 KiB) Viewed 441 times
And the configuration buffer:
Code: Select all
Now I am without idea how to continue...
It seems that I have lost > 70 Euros.
Dr. Ace Jeangle from Chalc-Elec does not answer anymore.
It seem that he leaves his customers without support or refund.
BTW. From their website:
Our main goal is to support electronic enthusiasts with their hobby electronic projects based on BeagleBoard, PandaBoard, BeagleBone, Raspberry Pi etc.