2nd project: Android controlled LED lighting

Overview

This project is about the use of an android phone to control LEDs via bluetooth. The system basically consist of an android phone, Arduino UNO, and bluetooth module. The android phone, through an application, sends data to Arduino via bluetooth. The Arduino UNO prototyping module then process the data from the android phone and control the brightness of each LED. The brightness control of each LED is implemented by using PWM pins of the Arduino UNO. The hardware can be powered by a 9V battery or a DC supply between 9 to 12V.

The Android Application

The application is made using sliders to vary the brightness of the LEDs. Each slider has a value of 0 to 255 from which  internet colors can be easily reproduced using the 3 sliders. Establishing the communication link is also done in the application. Basically, the app can search for other bluetooth devices, query for paired devices, establish RFCOMM channels/sockets, connect to a device, and send data over bluetooth.

Arduino UNO

Arduino UNO is an open-source electronics prototyping platform based on a flexible, easy-to-use hardware and software. It serves as the processor of the data from android phone. The value 0 to 255 from the android phone is translated to PWM wave with a frequency of approximately 490Hz to the pins 9, 10, and 11.

Bluetooth Module

The datasheet states that signal can reach up to 100m but actual distance may depend on the other communicating device. This module is using the UART interface in SPP configuration to connect to the Arduino UNO. In essence, the bluetooth module acts as a cable replacement between two devices.

Below is a demo video of the project.

Test and Debug

After writing your codes, it's time to test my application.

Using Android Virtual Emulator

One way to test your application is to run it on a virtual device.  The Android Virtual Device is included in the Android SDK tools.

1. Run the AVD manager.

On Eclipse, click Windows > Android SDK and AVD Manager.

2. Create a new virtual device.

- Name: virtual_galaxyS

- Target: Android 2.2

- SD card size: 512MiB

- Skin: Built-in: HVGA

* You can create several AVD with different screen sizes and Target versions.

3. Run your application.

On Eclipse, click Run > Run

* If you have multiple AVD, choose one that you want to use.

Now, have you made a good, working app already? Then good for you but most of the cases, it's not. So we need to debug.

Debugging

In debugging, the DDMS and DEBUG perspective view in the Eclipse IDE are  helpful.

The Debug Perspective in

Finally Upgraded to Gingerbread

I bought my Samsung Galaxy S with the Froyo version installed on it and since the Gingerbread update was released, I was very eager to upgrade mine. The most convenient way to update is to use the Kies software as provided by Samsung. Plug your phone, run the software, and update. That easy! (or just as I thought). It could have been that easy if I had known the problems that can be encountered in using Samsung Kies. 

Tirelessly waiting..

On my first try, I backed up my phone (contacts, pictures videos, etc.) first. When I started the Samsung Kies, it immediately prompt me that a firmware upgrade is available for my phone. And with eagerness, I clicked the "upgrade" button and it started. For a few minutes waiting, I noticed that the status bar was not moving. Thinking that it was just possibly a server or network slow down, I still waited for a few minutes until I finally gave up. Around 40 mins gone, still 0% in the progress bar. Since it is just my first try, it is worth for another one. But still the same thing happened. What could be the problem? My phone? My laptop? Time to ask for help to my friend (Google).

Consulting my friend

So I search for answers over the internet but all I can find are procedures that are the same of what I did.  Another option is to manually flash your phone using Odin which I don't want to try. Although I was tempted to manually flash my phone, I still did not try because I want the official release version. So I kept searching until I came across with a forum with their topic about upgrading using Kies. Someone told that he was experiencing problems in upgrading his phone thru Kies and found out that his internet connection seems to be the culprit. He was using a mobile broadband connection. It makes sense because I am also using