Setting up ACMP

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Setting up ACMP

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dporada
Contributor III

I'm trying to set up the ACMP for a LPC824 in MCUXpresso.  When I select the positive and negative inputs in the analog comparator peripheral window, is shows that the inputs are disabled.

Here's what it says: ACMP_IN3 » [25] P3[16]/J5[2]/P0_14-ADC2-ACMP_I3, Disabled

The pins are routed in the PINS window.

How do I enable the pins to work with the ACMP?

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3,341 Views
dporada
Contributor III

Here's my pins.

Screenshot 2023-01-11 at 7.17.04 AM.png

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3,338 Views
ZhangJennie
NXP TechSupport
NXP TechSupport

Hi dporada 

Please send me your demo project. I will check the problem directly.

Thanks

Jun Zhang

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dporada
Contributor III

Here's what I was playing with.

Thanks for looking.

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3,323 Views
ZhangJennie
NXP TechSupport
NXP TechSupport

Hi dporada 

I set the same ACMP pins and part as yours but it works well on my side.

I use SDK LPCXpresso824 v2.11, MCUXpresso IDE v11.6.1.

Please use the same version enviroment as above. Then follow attached steps in video to test again.

The project is also attached.

Thanks,

Jun Zhang 

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3,356 Views
dporada
Contributor III

I have attached a screen shot of the Peripheral setup that has the Disabled lines.

This was not actually my problem.  My problem was that the ACMP is not powered initially.  I am surprised that the software that is used to configure the ACMP, initialize it, and set up the interrupts does not power it up.  I did not see any mention in the documentation that this is required.  I found the line of code in lpcxpresso824max_acomp_interrupt example that disables a bit that allows the ACMP to power up.

Did I miss something obvious?

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3,348 Views
ZhangJennie
NXP TechSupport
NXP TechSupport

Hi @dporada 

You didn't configure ACMP pins. Please configure it in pin configuration tool, then you will see the pin enabled in ACMP component.

ZhangJennie_0-1673425776524.png

 

Have a nice day,

Jun Zhang

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3,365 Views
ZhangJennie
NXP TechSupport
NXP TechSupport

Hi @dporada 

Could you please send me screenshot of the peoblem?

Thanks.

Jun Zhang

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