Timer implementation for falling edge detection

[supriya Borchate]

Hi, 
I m using nrf 51822 development board. I want to implement timer in input mode to detect falling edge of the pulse.. It should give intrude when any falling edge is detected. .or is it possible to configure the external interrupt in falling edge.. ?

[ovrebekk]

Hi 

For this purpose you should use a GPIOTE channel in input mode. Then you can choose the detection edge (falling, rising or both), and enable an interrupt on the GPIOTE event. 

The nRF5 SDK contains a low level driver for the GPIOTE module which you can use to configure it, and it's documented here. 

Essentially you have to initialize the driver and set up an in channel using the nrfx_gpiote_in_init(..) function. 

Best regards
Torbjørn

[supriya Borchate]

Dear sir,

I have configure the GPIOTE in input mode to detect high to low transition .it should generate the one interrupt for one high to low transition ,but what is happening is its generating multiple interrupt even one there is one transition.what can be done to solve this issue?

[ovrebekk]

Hi

Do you check the event register in the event handler to verify that it is the same event that is generating all the interrupts?

Have you scoped the input line with an analog probe to make sure there are no unexpected transitions on the line?

Best regards
Torbjørn