National Semiconductor's LMX9838 Bluetooth IC

Here is one of my old projects:

I was able to acquire free 5 pcs sample of LMX9838 IC. I was able to use and evaluate it quickly. Here is my exact schematic (I created this in Eagle).

I was able to use this to control my microcontroller projects (LMX9838 in transparent mode) via
1. my Nokia E63 with a PythonS60 script.
2. USB Bluetooth using C# SerialPort Class

New Knowledge: Microsoft's XNA Game Development

It's Christmas Day. I had decided to learn something new today: Microsoft's XNA Game Development using C#. I always love being challenged, so I am giving myself a chance and do some self-study and see if I can (hopefully) develop some simple games using XNA.

While doing some useless XNA stuffs (just for learning purpose), here is my very very first attempt in creating collision-detection routine for two different objects:
http://img693.imageshack.us/i/bounce.mp4/

I am so excited with the learning adventure that I will be able to get and acquire with Microsoft XNA. :) :) :)

SMS Bomber for S60 using Python

Just for fun, I tried creating an SMS Bomber for S60 using Python just for learning purpose. I had tried it with my Nokia E63 and it works! ^_^

Here is the full source code:

SMS Bomber 00.08.03

Information Sharing: CS5463 Power Meter IC Calibration

I would like to share the calibration of the CS5463 Power Meter IC. My internet friends (co-engineers) asked me how I was able to use the calibration of the CS5463 in one of my projects (a low-cost power meter). I did this project long time ago, so if I will be having some minor mistakes here (due to passing time) please forgive me and just leave a comment. I am trying very hard to recall all the information (in my mind) needed for the calibration and to be able to share with those who needs the information.

The procedure in the datasheet is straightforward. However, many are confused in the graph shown in the datasheet:

Note: I only used DC signal for the whole calibration process. (No AC signal was used in calibration process)

Here are the steps/example for the calibration(only for Gain Calibration, I didn't include the Offset calibration as it is very easy to understand from the datasheet):
1. Inject a known DC voltage signal. For example, I will be injecting a well-calibrated voltage of 163.22mV. (you can use any voltage here depending on your preference, but this is the voltage I used on my computations.)
2. Perform the AC gain calibration.
3. After the AC gain calibration (and if done right), 163.22mV corresponds to 0.600 (instantaneous register value).

That's it. On actual operation (after being calibrated), if I got a value of 0.510, I just need to do a simple ratio and proportion to get the corresponding voltage.

163.22mV/0.600 = x/0.510
x=138.737mV; The voltage currently present at the channel being measured

With this method, I was able to compare the readings I got with a calibrated Chroma Power Meter versus my project. (there are small difference on the current reading due to the wrong type of current transducer that I used in the initial phase of this project)

With the data I got, I conclude that the method is accurate and precise. :)

My Asus EEE Bios Resurrection Project posted at hackaday.com

My project Asus EEE BIOS Resurrection was posted at Hack-a-day.com.
http://hackaday.com/2009/09/25/eee-pc-bios-resurrection/

I am so happy that I was able to finish this project successfully. I am very willing to help those Asus EEE users who are currently dealing with a corrupted BIOS.... Many many thanks to hackaday.com :)

Pyro Sequencer System

This is my first time to create an Electronic Firework Sequencer System. I created the software in Visual C# 2008. I integrated the Windows Media Player to be able to synchronize the fireworks with the music currently being played.

I used a low-cost PIC16F88 microcontroller with an RS-485 link + Serial-in-Parallel-out Shift Registers to be able to achieve 32 outputs. Everything was simulated on the Proteus PIC Simulator and the results turn out to be good. This is still a development in progress.