How to get ADC working on KDSK1.2+PEx

[yarannan]

Hi,

I am trying to read ADC value from a pot.

The chip configuration is MK20DX256VLL10 and software i used KDS3.0+ KSDK1.2+PEx.

I am sure there is no problem with hardware since it works in my old code with KDS2.0+PEx.

So I am thinking my ADC configuration and code sequence might went wrong. I checked

example code and couldnt figure out what went wrong.

Every time i run the code, the ADC value jumped from 255 to 0. It made no difference when I plug and

unplug pot. I have attached my code project and configuration screen shot.

Could someone help? Thanks in advance.

Yaran

Original Attachment has been moved to: adc_test.zip

[Alice_Yang]

Hello Yaran,

- Does the channel is right ?

- I recommend you use the latest version of KSDK1.3 , you can download it here :

https://freescale.flexnetoperations.com/control/frse/product?child_plneID=695287

Under the ksdk1.3 install directory , there is a adc16 demo , i have test the demo on

TWRK21D50m board , i think it is the same with your chip, you can refer to .

The demo is here :  KSDK_1.3.0\examples\twrk21d50m\driver_examples\adc16

Hope it helps

Alice

[yarannan]

Hi Alice,

Thanks for your attention. Firstly, I don't think i will switch KSDK1.3 for

now, but I will research more about it to know the differences with KSDK1.2.

Secondly, I am working on a project which is in a critical time schedule.

Back to the question I was asking above, I tried ksdk1.2 ADC demo example

for twrk60, it works as well. I dont doubt there is something wrong with sample code.

It just i am using process expert at the same time, i am thinking I did something with

one or some of component configuration parameters.

Lastly I am pretty sure i used correct channel. That was the first thing i check.

If you have a time to take a look, that would be great.

Thanks in advance,

Yaran

[Alice_Yang]

Hello Yaran,

Ok, i create one ADC sample project on SDK1.2+PE, while for i have not the MK20DX256VLL10 chip , i test on K21D50,

while it is the same , please see the attachment . And when i change the resistance values , the ADC will changed , this screenshot

is the result i test on my side :

- I checked your project about the configuration of fsl_adc16 component , it have no error , my project is  the same with yours (except the ADC chn).

So , i think you should be sure what about your ADC signal , you'd better check it use the oscilloscope or other instruments .

And also i don't know whether is the reason of MQX , could you please first create one simple bareboard project , only add fsl_adc , like my project(or directly

copy my code ), test whether it can work well .

Hope it helps

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Have a great day,
Alice

[yarannan]

Hi Alice,

I got it working. The reason is beside of the code, i have to add another line of code to

configure channel (which is channel b in my project). I thought i set up pin at PE configuration.

Thanks for your helps though.

Yaran