Overview
========
The bubble level demo demonstrates basic usage of the on-board accelerometer to implement a bubble level. A bubble
level utilizes two axes to visually show deviation from a level plane (0 degrees) on a given axis. This demo uses the
FTM/TPM to modulate the duty cycle of two on-board LEDs to gradually increase LED intensity as the board deviates from
a level state.

Toolchain supported
===================
- IAR embedded Workbench 7.50.1
- Keil MDK 5.17
- GCC ARM Embedded 2015-4.9-q3
- Kinetis Development Studio IDE 3.0.0
- Atollic TrueSTUDIO 5.4.0

Hardware requirements
=====================
- Mini/Micro USB cable
- FRDM-KL27Z board
- Personal Computer

Board settings
==============
No special settings are required.

Prepare the Demo
================
1.  Connect a USB cable between the host PC and the OpenSDA USB port on the target board.
2.  Open a serial terminal with the following settings:
    - 115200 baud rate
    - 8 data bits
    - No parity
    - One stop bit
    - No flow control
3.  Download the program to the target board.
4.  Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo
================
When the bubble level demo is programmed, simply tilt the board to see the LEDs illuminate. One LED color indicates
X-axis angle while the other indicates Y-axis angle.  When the example runs successfully, you can see the similar
information from the terminal as shown below.
Welcome to BUBBLE example
You will see the change of LED brightness when change angles of board
x= -72 y = -328
x= -16 y = -268
x= -40 y = -296
x= -40 y = -296
x= -96 y = -288
x= -96 y = -288

Customization options
=====================


