Using GPIO as button

[matan]

Hello,

I am trying to understand how to use an external button. In the first stage I am trying to replace the functionality of button0 on the DK with a GPIO.

I took the peripheral\BSP example and made the following changes:

1. pca10056.h:

       I replaced the line:

       #define BUTTON_1       11

       with the following line:

       #define BUTTON_1 NRF_GPIO_PIN_MAP(1, 3)

2. main.c:

      Added the lines:

     #define newPin NRF_GPIO_PIN_MAP(1, 3)

     nrf_gpio_cfg_input(newPin, NRF_GPIO_PIN_PULLUP);

I expected that whenever I connect the 5V on the board to pin 1.3, the button press event will fire. But it doesn't.

Any advice?

[Turbo J]

matan said:

I expected that whenever I connect the 5V on the board to pin 1.3

I expect the µC to blow up..

SCNR

NRF5x chips do not allow 5V on GPIO pins - see absolute maximum ratings in the PS.

Also, a button that is configured with a pullup enabled will be active low.

[matan]

I used the VDD from the board instead of the 5V. It works fine now, thanks for the help

[matan]

I now have a different problem. I can replace one of the existing buttons with my external button but I don't succeed to use it in addition to the existing ones.
Here are the changes I made.

In pca10056.h:
==============
modified:
   #define BUTTONS_NUMBER 5
added:
   #define BUTTON_5       NRF_GPIO_PIN_MAP(1,6)
   #define BUTTONS_LIST { BUTTON_1, BUTTON_2, BUTTON_3, BUTTON_4, BUTTON_5 }
   #define BSP_BUTTON_4   BUTTON_5

In sdk_config.h:
================
modified:
   #define GPIOTE_CONFIG_NUM_OF_LOW_POWER_EVENTS 5

In main.c:

========
Added:
   #define newPin NRF_GPIO_PIN_MAP(1, 6)
   inside bsp_evt_handler():
      case BSP_EVENT_KEY_4
   in main():
      nrf_gpio_cfg_input(newPin, NRF_GPIO_PIN_PULLUP);

[Amanda Hsieh]

Hi, 

I tested with the changes he posted in DevZone, it is working fine. I get a BSP_EVENT_KEY_4 event when I connect P1.06 to GND (We tested in this way because we don't have an external button). I did not use nrf_gpio_cfg_input(newPin, NRF_GPIO_PIN_PULLUP); in main. I do not see what good that should do, but he BSP library will configure the buttons correctly. 

-Amanda H