Editing LEDS_ON and LEDS_OFF

[tyler]

I am working on a project using a ble nano (nrf51822) using the Nordic SDK 8.1. In the examples I found a way to control the onboard led that uses the methods LEDS_ON and LEDS_OFF. I wanted to change my code to light up an external LED attached to a GPIO pin instead of the onboard LED. To do this I went into the header file for the board (custom_board.h) and changed the pin number from the onboard LED to an external LED. After doing this I was surprised to find out that LEDS_OFF turned the external LED on and LEDS_ON turned the external LED off. Now I'm wondering how I can fix this. My thoughts are I have 2 possible approaches: 1) Swap the LEDS_ON and LEDS_OFF functions by editing them. I can't figure out how I would do that though. How can I change these functions? Or 2) Create my own function that controls the LED attached to the GPIO pin and replace all instances of LEDS_ON and LEDS_OFF with it. How should I tackle this problem?

[Jørgen Holmefjord]

Hi,

The simplest solution would propably be to swap the definition of LEDS_ON and LEDS_OFF. They are defined in boards.h, which can be found in [SDK_ROOT]\examples\bsp\. Notice that changing this file will affect all other examples in the SDK, meaning you will have to change it back if you want to controll active low LEDs like the ones on the nRF51 DK with these functions again (to avoid getting inverted results).

Best regards,

Jørgen

[tyler]

Alright I see the methods. Is there a better way to change the functions? Like if I change one of the constants in the methods instead of just swapping the definitions?

[Jørgen Holmefjord]

You can swap all occurrences of OUTSET and OUTCLR in both defines, but they are otherwise identical, so the easiest solution would be to just swap the define name: LEDS_OFF -> LEDS_ON and vice versa.

[tyler]

Alright cool! How would I go about having 2 LEDS attached to different pins that flash at different times?

[Jørgen Holmefjord]

You should create timers, and toggle the LEDs in the timer handler. You can use the application timer library, see the application timer tutorial.