topic Re: HW trigger using LPIT in S32K

HW trigger using LPIT

shubhendu_shukl — Mon, 04 May 2020 13:31:20 GMT

Hi,

I am using adcPal2 in that lpit is being used to trigger my ADC1, it is working fine but when I am using lpit trigger time less that 25us code doesn't work only one time value gets updated, but as soon as I make trigger 40us it starts working fine, currently only 1 Channel is used for the conversion.
Please help me to understand why is it happening.

Re: HW trigger using LPIT

Alexis_A — Fri, 08 May 2020 00:04:37 GMT

Hello Shubhendu,

Can you let me know how many samples are you using per trigger conversion and the tick count waiting for the ADC_PAL module? It could be that the time it takes to sample and the waiting time is not enough to process the conversion before another trigger comes.

Best Regards,

Alexis Andalon

Re: HW trigger using LPIT

shubhendu_shukl — Fri, 08 May 2020 05:35:35 GMT

Hi Alexis,

Thanks for the reply,

I am using 12 samples per trigger conversion. I have tested that the ADC is taking about 10.4 uSec For the conversion,

One more issue I am facing that if there are 2 HW groups of different channels in Single ADC (2 different LPIT channels for triggering ADC HW trigger ), the only the group which is triggered 1st works the other group never responds

Re: HW trigger using LPIT

Alexis_A — Wed, 13 May 2020 15:08:28 GMT

Hello Shubhendu,

Unfortunately, in the ADC_PAL driver, you can only trigger one conversion per instance and if you attempt to do it the enable function will return a busy. What you could do is link the conversions channels if you want to use two different triggers and trigger different group conversions in each one.

Best Regards,

Alexis Andalon