ADC SW Triggering not working

[EE_CW]

Hi together

In a project I use a S32K148.

There I want to use the ADC0 to measure different signals.

For this i configured the different channels:

Now I have the problem, that only the first channel is working.

I initialized the the converter like this:

To start a conversion and wait until conversion is done I use the following functions (example from adConv0_ChnConfig1):

If I debug the application, it seems that the conversion is not getting started, because within ADC_DRV_WaitConvDone() the active flag is checked.

When the conversion is not started, I think the flag will be not active. In this case the ADC_DRV_WaitConvDone() will return and there is no result.

If I use ADC_DRV_GetConvCompleteFlag() instead of ADC_DRV_WaitConvDone() , the programm blocks at this line. In my opinion this means also that the conversion is not started.

What could be wrong with that? Channel 0 (ADC_INPUTCHAN_EXT4) is working, the others don't work.

Thanky for your help

Regards

Mario

[PetrS]

Hi,

in Software trigger mode just channel 0 can be used to start a conversion. Writes to other channels do not initiate a new conversions. 

BR, Petr

[EE_CW]

Hi Petr

Thanky for the information.

Is there a other similar way to initiate a conversion on the  other channels?

I use the adc component from Processor Expert

It seems weird to me, if there is a possibility to setup different channel configurations but only one channel can be used then.

Best regards

Mario

[PetrS]

Hi,

channel configuration defines which external channel will be measured and if interrupt is generated upon conversion. In SW trigger mode just a channel 0 initiate a conversion and so channel 0 must be used but you can select desired channel configuration within driver function.

If you want to convert more channels, e.g. in a chain, then HW trigger mode can be selected and PDB module can be used to trigger more channels to be converted, either at a specific time or in so called back-to-back mode.

You can refer to below example for PDB usage for multiple channel conversion

https://community.nxp.com/docs/DOC-343295

BR, Petr

[EE_CW]

Hi Petr

I want to convert more multiple channels, but not at the same time. I want to have a function where I can start a conversion of a single channel (whenever it is needed to be converted) during the programm sequence.

But if you say that is not possible, I will have a look at your example.

But I found now a solution for me:

I used the adc_pal component of processor expert.

There I set u the different signals each in a seperate group.

Now I can start each single group conversion independent from each other.

Regards Mario