topic Re: [MKW01] LPTMR internal pullup in Kinetis Microcontrollers

[MKW01] LPTMR internal pullup

giancarlozanuz — Tue, 06 Mar 2018 16:51:10 GMT

Hello, i'm using the LPTMR as a pulse counter, but the internal pull-up is not working in this mode.

The pin I'm using is the PTE17 - ALT6 (LPTMR0_ALT3), and the pullup works fine as a GPIO, but when I change the mux to ALT6 the pin goes floating.

Here's the code:

      PORT_HAL_SetPullMode(PORTE,17u,kPortPullUp);
      PORT_HAL_SetPullCmd(PORTE,17u,true);
      PORT_HAL_SetMuxMode(PORTE,17u,kPortMuxAlt6);           /* PTE17 - ALT6 */

With an external pullup it works fine, but I need to use the internal for my hardware.

Thanks in advance.

Re: [MKW01] LPTMR internal pullup

mjbcswitzerland — Tue, 06 Mar 2018 18:16:49 GMT

Maybe the PORT_HAL_SetMuxMode() is bad and clears the pull-up setting.
Try putting it first and see what happens.

Or just set
PORTE_PCR17 = 0x00000603; // (PORT_MUX_ALT6 | PORT_PS_UP_ENABLE)

Regards

Mark

Re: [MKW01] LPTMR internal pullup

giancarlozanuz — Wed, 07 Mar 2018 17:25:24 GMT

Hello Mark,

Thanks for your reply, but it didn't work either. The pin is still floating around ~1V.

I have checked the register and it is correct (0x00000603), as you can see:

What else can it be?

Thanks.

Re: [MKW01] LPTMR internal pullup

giancarlozanuz — Fri, 13 Apr 2018 12:10:51 GMT

Well, should I assume this is not possible at all? Kind of disappointed.

Re: [MKW01] LPTMR internal pullup

mjbcswitzerland — Fri, 13 Apr 2018 16:23:01 GMT

Giancarlo

I don't have a KW01 to test on.
If you are reading the value back as expected and you are sure that there is no error in the measurement it would sound like it is not possible with that chip.

Regards

Mark