Using two GPIOTE config to a single pin

[osenjw]

In another thread entitled:

Change in GPIO to start/stop timer and fire interrupt

The following code is used:

  NRF_GPIOTE->CONFIG[0] = (GPIOTE_CONFIG_POLARITY_HiToLo << GPIOTE_CONFIG_POLARITY_Pos)
        | (myPin << GPIOTE_CONFIG_PSEL_Pos) // using GPIO 5 as input
        | (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos);

    //// Configure GPIOTE channel 1 as event that occurs when pin 5 changes from digital
    //// low to hi.
    NRF_GPIOTE->CONFIG[1] = (GPIOTE_CONFIG_POLARITY_LoToHi << GPIOTE_CONFIG_POLARITY_Pos)
        | (myPin<< GPIOTE_CONFIG_PSEL_Pos) // using GPIO 5 as input
        | (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos);

In the nRF51 RM, there is a statement: Each GPIOTE channel is associated with one physical GPIO pin through the CONFIG.PSEL field...

Is the above code breaking this rule? Are two configurations being mapped to a single pin?

Would the correct code be to look for a change, then check the PIN state in the ISR to determine whether it was HiToLo or LoToHi?

If so, what would be the recommended debounce approach?

[Susheel Nuguru]

+1 for RK, It does break the rule, could be some side effects if myPin is toggling close to system clock frequency. But at lower frequencies on myPin (<4MhZ) this would work (not recommended though)