Falling edge detection through I/O expander Thingy 52

[Rilleaa]

Hello everyone.

Iam working on a project where i need to detect a falling edge from a ADC (ADS1298) when new data is ready at a sample rate of 500SPS. I have the issue that all the fast changing pins are used for the SPI communication with the ADC so iam left with using one of the EXT pins through the I/O expander. Is there any way to enable a interupt on falling edge on these pins or do i have to write code to somehow detect a falling edge using drv_ext_gpio_pin_read() funcion just by reading the pin value?

Thankful for help. 

//Rilleaa

[ketiljo]

It will probably be better to use a direct GPIO. MOS1 is connected to P0.18. If you remove Q6, you can solder a wire directly to the pad and use that to detect the interrupt from the ADC.  

[Rilleaa]

Thx Ketiljo for the reply then i know what would be a better way of doing it. At the moment i got it to work on the EXT pinns but using interupts is obviously better as the processor can handle other processes in between interupts.

//Rilleaa