BRT Community
General Category => Discussion - EVE => Topic started by: Qrenz on June 02, 2020, 09:18:40 AM
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Hi, on several commercial product using EVE with capacitive touch, they use Focaltech IC for example FT5206.
So from EVE IC (FT811, BT815) to FT5206 was connected by I2C, in total 4 pins (SDA, SCL, RST, INT).
What i want to know is the connection from FT5206 to the capacitive panel, what is it and what is the pin definition?
Thank you.
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These touch controllers measure the capacitance of points on a grid.
The datasheet has example circuits.
If you just would like to know how this works, checking out a microcontroller with an integrated touch controller
might offer more insight.
Many controllers from Microchip for example feature a "Peripheral Touch Controller" or PTC that can be used
in a variety of ways.
One such a controller out of many would be the ATSAMC21.
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Hello,
You would need to look up the datasheet for the LCD panel you are using to determine its pinout.
You can then cross reference this with the FT5206 datasheet to establish which connections need to be made.
Best Regards,
BRT Community
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Hi, so it really depend on the LCD panel that we use.
Is there a LCD panel that only provide pins for CTP for example: supply, gnd, scl, sda, rst, and int
and other LCD panel have many more pins for the CTP function (probably 20-30 pins), what's the different?
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Isn't that the "norm" that the panels integrate the touch controller?
At least I have not found a panel yet that has the rasterizer for capacitive touch attached but no touch-controller.
I could provide dozens of examples with touch controller.
Please provide one example of a display with capacitive touch without touch controller.
The reason for this would be that the lines to measure the capacitance need to be a lot more sensitive and therefore are much more prone to faults, adding a connector would make the connections a lot longer, add the resistance from the connector and would require a much bigger connector.
Usually the touch controllers on the displays are even shielded with a small metal plate that also provides stiffness.
Adding a 6 to 12 pin connector for the I2C connection of the touch-controller is something entirely different.
I built a unit with a couple of touch-buttons for a customer and went with a touch-controller chip on a separate board due to mechanical restrictions.
And to keep the story short, I would not do it this way anymore.
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Hello,
Yes, in my experience it is the norm that capacitive touch panels usually integrate the controller.
Qrenz, I can provide the part number of the panels used on our CTP development modules if you are interested.
Best Regards,
BRT Community