NRF5 SDK template

This repository is intended to simplify development for NRF52 (most notably NRF52832). It wraps the build system as a meson componenent, and adds a simple wrapper around SoftDevice initialization, so the developer can easily create new applications without copying existing code from repo to repo.

Usage:

• Add this repo as a git subproject
• Symlink sdk location to a file named sdk in the root of this repository:

export SDK_ROOT=/path/to/unzipped/sdk
ln -s $SDK_ROOT sdk

• Create a meson.build file (for example with meson init).
  • Set optimization level, specs, etc...
• Include this repo with subdir, and include the target-related options from targets/*

Here is a complete example:

project('ble_blinky', 'c',
  version : '0.1',
  default_options : [ 'optimization=s' ])

subdir('nrf-ble-template/targets/nrf52832')
subdir('nrf-ble-template')

executable('ble_blinky',
           'blinky.c',
           dependencies : nrf_sdk_dep)

• Create a sample application:

#include <nrf_gpio.h>

#include "ble.h"

#define LED_PIN		27

static inline void led_switch(bool on) {
	nrf_gpio_pin_write(LED_PIN, on);
}

static inline void led_init(void) {
	nrf_gpio_pin_dir_set(LED_PIN, NRF_GPIO_PIN_DIR_OUTPUT);
	led_switch(false);
}

static void connection_events_handler(ble_evt_t const *event, void *user)
{
	/* Other events are already handled by the library */
	switch (event->header.evt_id) {
	case BLE_GAP_EVT_CONNECTED:
		led_switch(true);
		break;

	case BLE_GAP_EVT_DISCONNECTED:
		led_switch(false);
		break;
	}
}

NRF_SDH_BLE_OBSERVER(connection_observer, BLE_C_OBSERVERS_PRIORITY, connection_events_handler, NULL);

/* You can add custom error logic here, see SDK for more examples */
void app_error_fault_handler(uint32_t id, uint32_t pc, uint32_t _info)
{
	__disable_irq();
	led_switch(true);

	while(1);
}

int main(void)
{
	led_init();
	ble_c_init();

	for (;;) {
		sd_app_evt_wait();
	}
}

• Get yourself a working arm-gcc toolchain (e.g arm-none-eabi-gcc). You need to specify a valid cross-file with --cross-file while creating a build directory. You can use the one that is provided by this template if your compiler's executable name matches:

meson build --cross-file nrf-ble-template/scripts/arm-none-eabi.build`
ninja -C build

• See if the build works!

NRFX and NFC tag emulation libraries

Since not everyone may need such functionalities NRFX sources are kept separate from nrf_sdk_dep. You can use nrf_nfc_dep and nrfx_dep if you want to use NFC tag emulation and NRFX, respectively. That will add required sources and include directories to your build. Please note that porting such functionalities here was like a game of whack-a-mole since required flags and defines are not clearly specified (not to mention that excluding the entire source file using preprocessor is weird and senseless if that could be done on the build system side...). I'm just saying that there is a chance that you'll encounter some issues and YMMV.

Github actions

This repo contains Github Actions rule that simplifies setting up this template:

steps:
- name: Install apt dependencies
  run: sudo apt-get install meson ninja-build gcc-arm-none-eabi
- name: Checkout source
  uses: actions/checkout@v3
  with:
    submodules: recursive
- name: Checkout NRF52 SDK
  uses: dossalab/nrf-ble-template
- name: Build
  run: |
    meson build --cross-file=nrf-ble-template/scripts/arm-none-eabi.build
    ninja -C build

Other notes

./scripts contains a program.sh script that can help flashing the target