Help with calculating cadence from a pulsing input

[Brantel]

I am working on modifying the ant+ sdm example to hack my treadmill. Got the example running and talking to my Garmin watch and the display simulator. All of that seems straight forward and easy to manipulate.

Now I want to use one of the gp inputs to send the DK board an input signal that pulses once per rev of the drive roller of the treadmill.

I have looked at the bsp example as well as the bsp tutorial listed above. I think I can figure out how to use the bsp library and trigger events based off of the input (similar to a button press once per rev)

Using this input I will need to do some math to inject a cadence variable into the example sdm code and am looking for the way to pull that off.

I am thinking it will take something like storing the time at each pulse then subtract the previous reading from the most current reading and then divide 60(or whatever the time units are) by the result to get the cadence of pulses per minute.

I am a newbie at this code stuff so please be patient with me!

[FormerMember]

Instead of using the BSP library to trigger events, I would recommend you to use GPIOTE. For a starting point, the GPIOTE example in the SDK can be used.

[Brantel]

This is making my head swim. Trouble finding enough clues in the documentation to find a starting place. I want to determine the time between pulses of an input in milliseconds. This is child's play with an arduino and the arduino IDE but for a newbie on C and this DK board, I am struggling.

[FormerMember]

Aha, I misunderstood.

For timer, I would recommend you to use the Application timer library.

A tutorial for getting started with the Application timer library can be found here. The tutorial was made for SDK 11, but I doubt that it has changed much for SDK 12 and 13.