Using adafruit cap touch


#1

I would like to use the adafruit cap touch display with my grove pi: https://learn.adafruit.com/adafruit-2-8-pitft-capacitive-touch/. The screen physically fits just fine, but it seems to use the same i2c gpio pins. The grovepi works fine without the screen software installed. Once we install the software for the screen, then the screen works, but then the grovepi doesn’t work. When we test the grovepi with i2cdetect, the results indicate that it won’t work, and if we run various Python scripts we get nothing but IOErrors when trying to talk to grove sensors.

I know the I2C bus can be tricky to use and to stack multiple devices on. The pullups on them might be falling.

Steve


#2

Hey,
PiTFT2.8 does use the I2C lines which are used by the GrovePi too but I am not sure how they are using it so it is very likely that it might be breaking things. It would be great if you could just connect the PiTFT and run sudo i2cdetect -y 1 then just connect the GrovePi and run the i2cdetect command again and then connect both the GrovePi and PiTFT and run the command again and spot the difference or post the result here.

If you can work without the touchscreen, then it would be possible to use a ribbon cable to jumper everything from the GrovePi to the PiTFT without the I2C.

-Karan