Sorry if this question has already been asked and/or answered. I have not seen an answer to any questions like this yet. Currently I have only been able to get my UDOO to read GPIO input of the IMX6 when the pin is attached to ground. Is there any way to get the IMX6 (linux) to read +3.3v input?
Sounds like the GPIO pin is biased to high with a pull up resistor . So pick a pin which isn`t used for I2C or switch off the pull up resistor . AND don`t forget both boards are linked , so if the Sam part is input and pull up resistors set by default , you will have to check both sides to make sure they are off.
