/**
@defgroup    boards_nrf51dongle nRF51 Dongle
@ingroup     boards
@brief       Support for the Nordic nRF51 Dongle

## Overview:
The nRF51822 is a multi-protocol SoC ideally suited for Bluetooth® low energy
and 2.4GHz ultra low-power wireless applications from Nordic Semiconductor. The
nRF51822 is built around a 32-bit ARM® Cortex™ M0 CPU with 256kB flash + 16kB
RAM. The embedded 2.4GHz transceiver supports Bluetooth low energy as well as
2.4GHz operation.

Nordic's development kit contains two different boards:
- **pca10000**: a USB-dongle containing the nRF51822 and a RGB-Led
- **pca10005**: two a basic nRF51822 boards making the MCU pins available

While the pca10000 contains an on-board J-Link debugger, the pca10005 boards
have to be flashed/debugged using the (included) external J-Link device.

## Hardware:
![Nordic Semiconductor nrF51822 Development Kit](https://www.nordicsemi.com/var/ezwebin_site/storage/images/media/images/products/nrf51822-dk/422047-1-eng-GB/nRF51822-DK.jpg)

| MCU        | NRF51822QFAA      |
|:------------- |:--------------------- |
| Family | ARM Cortex-M0     |
| Vendor | Nordic Semiconductor  |
| RAM        | 16Kb  |
| Flash      | 256Kb             |
| Frequency  | 16MHz |
| FPU        | no                |
| Timers | 3 (2x 16-bit, 1x 32-bit [TIMER0]) |
| ADCs       | 1x 10-bit (8 channels)        |
| UARTs      | 1                 |
| SPIs       | 2                 |
| I2Cs       | 2                 |
| Radio         | 2.4GHz BLE compatiple, +4dBm to -20 dBm output, -93 dBm RX sensitivity |
| Vcc        | 1.8V - 3.6V           |
| Datasheet  | [Datasheet](http://www.freqchina.com/cn/down.asp?ID=135) (pdf file) |
| Reference Manual | [Reference Manual](http://www.100y.com.tw/pdf_file/39-Nordic-NRF51822.pdf) |


## Flashing the Device:
The nRF51822 PC10000 board is shipped with an on-board JLink debugger.
However the PC10004/5 board uses an external flash tool as seen in the Image
above. Under Linux, the easiest way flashing the nRF51822 is using the JLink
tool(version >4.85) from [Segger](http://www.segger.com/jlink-software.html).

To interact with the board just start the tool using the following command:
`# JLinkExe -device nrf51822`

For RIOT itself there is a Flash-Script available. When using any of the
Examples type in the following command:
`# Make -B clean flash`
 */