topic Re: How to use GPIO interrupt and output wave from GPIO? in LPC Microcontrollers

How to use GPIO interrupt and output wave from GPIO?

JiaAn — Fri, 23 Apr 2021 03:30:11 GMT

Hi,
LPC chip is a new thing to me. I want to trig interrupt by a pin and interrupt will output wave from another pin. But I am stuck. The code is too different between LPC4370 and the MCU I used before.
I can't find an example code about GPIO interrupt. I did try Google but unfortunately, the codes I googled can't work on my board.
Can anyone please help me point out which documents should I read or where can I get an example code that can work on LPC4370?

Re: How to use GPIO interrupt and output wave from GPIO?

JiaAn — Fri, 23 Apr 2021 05:32:19 GMT

I just figure out that I can output GPIO by using these code:

Chip_GPIO_SetPinDIROutput(LPC_GPIO_PORT, 3, 4); //Set pin direction
Chip_GPIO_SetPinState(LPC_GPIO_PORT, 3, 4, false); // Output low
Chip_GPIO_SetPinState(LPC_GPIO_PORT, 3, 4, true); // Output high

But I still don't know how to use GPIO to trig interrupt. Still need help. Thanks.

Re: How to use GPIO interrupt and output wave from GPIO?

Alice_Yang — Fri, 23 Apr 2021 09:38:45 GMT

Hello JiaAn,

Please download LPCopen for lpc4370, there is GPIO interrupt demo, you can directly run it on your chip.

Download from:

https://www.nxp.com/design/microcontrollers-developer-resources/lpcopen-libraries-and-examples/lpcopen-software-development-platform-lpc43xx:LPCOPEN-SOFTWARE-FOR-LPC43XX

It support MCUXpresso IDE, KEIL, IAR, recommend the first one, it is free and support by NXP. After download , you can find the gpio demo.

Download IDE from: https://www.nxp.com/design/software/development-software/mcuxpresso-software-and-tools-/mcuxpresso-integrated-development-environment-ide:MCUXpresso-IDE

And in fact, if you install MCUxpresso IDE, the lpcopen is inside it by default, I take a video about how to open it under MCXUpresso IDE for you,

please see my attachment.

Hope it helps.

Alice

Re: How to use GPIO interrupt and output wave from GPIO?

JiaAn — Mon, 26 Apr 2021 01:45:44 GMT

@Alice_Yang Thank you so much. I found the example code and it really helped me!

But I still have two questions for that example code.

#define TEST_BUTTON_PORT 0
#define TEST_BUTTON_BIT 7
#define TEST_BUTTON_PIN_PORT 2
#define TEST_BUTTON_PIN_BIT 7
#define TEST_BUTTON_MODE_FUNC SCU_MODE_FUNC0

I found PIN_PORT and PIN_BIT on the datasheet. but I can't figure out what is TEST_BUTTON_PORT and TEST_BUTTON_BIT? And which document should I read for TEST_BUTTON_MODE_FUNC?

So I still need your help. And thank you for helping me

Re: How to use GPIO interrupt and output wave from GPIO?

Alice_Yang — Mon, 26 Apr 2021 06:54:32 GMT

Hello JiaAn,

This just a defined name in the code, it is the same with PIN_PORT and PIN_BIT.

For example

#define TEST_BUTTON_PORT 0 ,

this means PORT0 .

#define TEST_BUTTON_MODE_FUNC SCU_MODE_FUNC0

This means config this pin as FUNC0. You can find

#define SCU_MODE_FUNC0 0x0 /*!< Selects pin function 0 */

Alice