/**
@defgroup    boards_limifrog-v1 LimiFrog Version 1
@ingroup     boards
@brief       Support for the limifrog-v1 board

## Overview
LimiFrog-v1 arose from the La BlueFrog board. LimiFrog-v1 contains the first
hardware revision of that kickstarter project. LimiFrog-v2 is already there and
the RIOT support will follow.
[LimiFrog](https://github.com/LimiFrog/LimiFrog-HW)
features a variety of sensors as well as an OLED Display and a BLE
(Bluetooth Low-Energy) module.

## Hardware
![Limifrog-v1](https://www.cnx-software.com/wp-content/uploads/2015/09/Limifrog.jpg)
![limifrog-v1 pinout](https://raw.githubusercontent.com/wiki/RIOT-OS/RIOT/images/limifrog-v1_pinout.png)

### MCU
| MCU                   | STM32L151RC                               |
|:--------------------- |:----------------------------------------- |
| Family                | ARM Cortex-M3                             |
| Vendor                | ST Microelectronics                       |
| RAM                   | 32KiB                                     |
| Flash                 | 256KiB                                    |
| Frequency             | 32MHz (no external oscillator connected)  |
| FPU                   | no                                        |
| Timers                | 8 (8x 16-bit, 1x 32-bit [TIM5])           |
| ADCs                  | 1x 42-channel 12-bit                      |
| UARTs                 | 3                                         |
| SPIs                  | 2                                         |
| I2Cs                  | 2                                         |
| Vcc                   | 1.65V - 3.6V                              |
| Datasheet             | [Datasheet](http://www.st.com/st-web-ui/static/active/en/resource/technical/document/datasheet/DM00048356.pdf) |
| Reference Manual      | [Reference Manual](http://www.st.com/web/en/resource/technical/document/reference_manual/CD00240193.pdf) |
| Programming Manual    | [Programming Manual](http://www.st.com/web/en/resource/technical/document/programming_manual/CD00228163.pdf) |

## User Interface

2 Buttons:

| PIN       |
|:--------- |
| PA15 (IN) |
| PC8 (IN)  |

1 LED:

| NAME   | LED_RED|
| -----  | ----- |
| Color  | red   |
| Pin    | PC3   |

## Implementation Status

| Device                                        | ID                        | Supported | Comments                                  |
|:--------------------------------------------- |:------------------------- |:--------- |:----------------------------------------- |
| MCU                                           | STM32L151RC               | partly    | Energy saving modes not fully utilized    |
| Low-level driver                              | GPIO                      | yes       |                                           |
|                                               | PWM                       | yes       |                                           |
|                                               | UART                      | yes       |                                           |
|                                               | I2C                       | yes       |                                           |
|                                               | SPI                       | yes       |                                           |
|                                               | Timer                     | yes       |                                           |
| Ambient Light Sensor                          | ST VL6180X                | no        | planned                                   |
| Accelerometer                                 | ST LSM6DS3                | no        | planned                                   |
| Magnetometer                                  | ST LIS3MDL                | no        | planned                                   |
| Gyroscope                                     | ST LSM6DS3                | no        | planned                                   |
| atmospheric pressure (and altitude) sensor    | ST SLPS25H                | no        | planned                                   |
| Microphone                                    | Knowles SPU0414HR5H-SB    | no        | planned                                   |
| OLED Display                                  | Densitron DD-160128FC-1A  | no        | planned                                   |
| BLE                                           | Panasonic PAN1740         | no        | planned                                   |

## Flashing and Debugging the device

The LimiFrog-v1 has no on-board programmer nor an USB-UART converter. It can
be programmed by using the integrated ST-Link/V2 programmer of any STM32Fx-
discovery board. See the Hardware subsection in Flashing and Debugging section
[here](@ref boards_yunjia-nrf51822) for an example.
Another way is to use a stand-alone ST-Link V2 programmer as shown in the
picture.

![limifrog-v1 wiring](https://raw.githubusercontent.com/wiki/RIOT-OS/RIOT/images/limifrog-v1_wiring.png)
![limifrog-v1](https://raw.githubusercontent.com/wiki/RIOT-OS/RIOT/images/limifrog-v1_conntected.png)

To debug the device you may also want to use a stand-alone UART converter and
connect it to the pins PC10 and PC11 and keep the programmer plugged.
 */
