topic Re: Setting up ACMP in MCUXpresso General

Setting up ACMP

dporada — Wed, 04 Jan 2023 18:37:16 GMT

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?

Re: Setting up ACMP

ZhangJennie — Fri, 06 Jan 2023 10:52:09 GMT

Hi @dporada

Could you please send me screenshot of the peoblem?

Thanks.

Jun Zhang

Re: Setting up ACMP

dporada — Mon, 09 Jan 2023 14:27:02 GMT

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?

Re: Setting up ACMP

ZhangJennie — Wed, 11 Jan 2023 08:30:12 GMT

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.

Have a nice day,

Jun Zhang

Re: Setting up ACMP

dporada — Wed, 11 Jan 2023 12:31:09 GMT

Here's my pins.

Re: Setting up ACMP

ZhangJennie — Thu, 12 Jan 2023 03:45:09 GMT

Hi dporada

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

Thanks

Jun Zhang

Re: Setting up ACMP

dporada — Thu, 12 Jan 2023 14:34:05 GMT

Here's what I was playing with.

Thanks for looking.

Re: Setting up ACMP

ZhangJennie — Sun, 15 Jan 2023 14:39:42 GMT

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