FT6206 Capacitive Touch Breakout Board Interrupt Problems

[wespiard]

Hello,

We are using the 2.8 TFT LCD with Cap Touch Breakout Board (https://www.adafruit.com/product/2090), and we are having some problems with the interrupt mode for the device. In the FT6206 datasheet, there are two options listed for interrupts: polling mode and trigger mode. When in polling mode, the IRQ line goes low and stays low until the touch is released. In trigger mode, there are continuous (approximately) 1 ms low pulses the whole time the touch screen is pressed.

We ordered two of these breakout boards around 3-4 months ago, and we could use polling mode with these two devices without any problems. (Please note that we are using our own drivers for this device.) Now, we ordered more breakout boards and the first two we have tested behave the same while in both polling and trigger mode, i.e., they both behave as if in trigger mode. We have tried writing to the interrupt control register and reading back from it, and the data we read is identical to the data we write. Even though it seems as if the correct data is being written, the device still behaves as if it is in trigger mode.

Below are links to pictures of both versions of the breakout board, the first link being the old version, and the second being the new version. There are some subtle differences in version/model numbers which leads us to the assumption that there were modifications made to the design.

This is a link to pictures of the old version: https://imgur.com/a/h0VTijm
This is a link to pictures of the new version: https://imgur.com/a/imjGC4W

Was anything perhaps changed from the old boards to the new ones? Is the problem we are having related? If any other changes were made, can they please be listed?

Thank you!

[wespiard]

Can I bump this? We still haven't figured it out.

[adafruit2]

hiya, sorry we didn't see this
it sounds like the pin works, but the firmware inside the FT2606 changed. we get the TFTs fully assembled and don't control the firmware so there's no way we have to change the behavior. hopefully you can use both types with your code. we tend to just manually i2c poll in our code anyways since there's no FIFO!

[wespiard]

Thank you for the confirmation.

We resorted to checking the event flag bits within the XH registers to determine whether a touch is being made or not. Is this what you are referring to by "i2c polling"?

[adafruit2]

yep! we just query it it see if its got a current touch point

[wespiard]

Okay, thanks.

Also, do the "Touch ID" bits within the YH registers work?

[adafruit2]

can't remember, its been a while - check the arduino code - everything we got working is in there!