Correct method to drive GPIO?

[fastwalker2]

Hi All,

I have an LPXCpresso43S67 board which I finally have working with the LPCxpresso IDE.  I want to simply drive one of the GPIOs that goes to the Arduino headers.  Looking online I found this pic. below describing the pins.  So for example if I wanted to drive P2_13, would the code be?  I.e. what is the mapping of ports & pins to those Arduino headers?

Chip_GPIO_SetPinState(LPC_GPIO_PORT, 2, 13, true);

[frankchiu]

Hi Sean,

Just to make sure, have you download LPCOpen? It contains many code examples.

You said you have an LPCXpresso43S67 board, but the picture you attached is for LPCXpresso4337.

I don't know whether two boards are the same, and I assume you have the first one.

I see P2_13 is in the same position on my board.

You can find the official documents of MCU LPC43S67JET100 on the board at:

LPC43S67JET100|Arm® Cortex-M4/M0|32-bit MCU|NXP    

In the data sheet, you can find pin description.

For example, the pin P2_13 is in p. 19. It can be configured as GPIO1[13] in FUNC0.

Therefore, you may try the following code:

    Chip_SCU_PinMuxSet(0x2, 13, (SCU_MODE_INACT | SCU_MODE_FUNC0));  /* P2_13 => GPIO1[13] */
    Chip_GPIO_SetPinDIROutput(LPC_GPIO_PORT, 1, 13);
    Chip_GPIO_SetPinState(LPC_GPIO_PORT, 1, 13, (bool) true);

Hope this helps.

Frank

[simon_prentice]

Hi Frank,

1. Where does the information "/* P2_13 => GPIO1[13] */" come from?

I can't find it in UM1053 LPC User Manual or LPC4370 Data Sheet.

2. What settings are required for Port 3 Pin 3?

Thanks,

Simon.

[frankchiu]

Hi Simon,

I am not sure if I understand your problems correctly.

I guess you are trying to make Port 3 Pin 3 on LPC4370 a GPIO pin?

According to the data sheet I found at  https://www.nxp.com/docs/en/data-sheet/LPC4370.pdf ,

p. 18 shows that P3_3 cannot be configured as a GPIO pin.

However, if you want to configure P3_4 to a GPIO pin, the above code becomes:

   Chip_SCU_PinMuxSet(0x3, 4, (SCU_MODE_INACT | SCU_MODE_FUNC0));  /* P3_4 => GP  IO1[14] */

P3_4 => GPIO1[14] comes from the first row of description of P3_4.

Got it?

Regards,

Frank

[simon_prentice]

Thanks Frank.

I was reading things completely back-to-front.

All good now (although slightly embarrassed).

[frankchiu]

Hi Simon,

Don't be embarrassed, everyone learns like this. :smileyhappy: