Sunday, July 21, 2013

The "MoBotGeek Initiative"

Having been brainstorming for a Thesis Topic for my Masters Degree, I have come up with an initiative. The plan is create a Z8F4821 mCU Based I/O board to be used as an interface board for known sensors in the market. "Shared Library" for C++ Programming will be created for each sensor so as to unburden the user from the details of configuring the mCU as an interface board between the sensor of choice and a desktop computer.This board is envisioned to used in research studies and hobbyist projects.

These are the initial features of the board:
  • Analog Input
  • SPI Input
  • UART Input
  • I2C Input
  • D.I/O
  • and PWM
Features will be changed as per advice of my Mentor and "Special Problems Class " Professor.

You can send your advises and/or suggestions regarding the board through posting. 

Will be posting more details and updates regarding this.

Hope to see you in my next posts.

Friday, April 19, 2013

Alitaptap - A Strobe Light Controller for Motorcycle LED Strip Aesthetics Lighting

I just recently bought a secondhand Honda Ex3 Malaysia Motorcycle.

After having its engine and other mechanical parts restored to its optimum condition, the next thing I had in mind is to add aesthetic lighting. I went to a local electronics store and found these 12V DC Operated LED Strip. These are perfect for what I had in mind.

These LED strip are low profile and sealed. Unfortunately, they operate at 12V DC while my motorcycle electrical system can only supply a maximum of 6V DC.

Luckily, I remembered the voltage doubler circuit introduced to us in our Electronics class during my college years. The voltage doubler circuit introduced to us at that time needs an AC input. Though its not the right circuit for my problem but it gave me a reason to look for a voltage doubler circuit that works with DC input. The search led me to this very cool site full of interesting useful circuits, the Out from which I got this circuit This site did not only post the circuit schematics but also a detailed description of how the circuit works.

Since some of the components shown in the circuit schematics is not locally available, I had to replace them with similar components that are available here in my place.  The schematics of the modified circuit is shown in figure below.

(Replace the 1N4001 with 1N5818 if the later is available. The 1N5818 has lesser threshold voltage thus the final output has a lesser drop in voltage. )

Bought and soldered all components into a perforated board. The resulting circuit is shown in the following figures.

The last picture shown above shows the copper portion of the perforated board and the solder bridges made to connect the pins of the circuit components.

I tested this circuit using a 5V DC input. The output voltage measured, using my analog multimeter, is 8V. Theoretically, it should have been 10V but due to the diode and transistor P-N junction threshold voltages, the output voltage is minimized to 8V.

Tested this circuit again using the battery of my motorcycle and with the LED Strips connected to the output port. As can be observed, the LED Strip lights up brightly.

The power supply part is done. The next part is the strobe controller which I will be calling as Alitaptap. Alitaptap is the Filipino term for firefly. I have decided to make one out of the NE555 Timer in Astable Multivibrator (with diode) Configuration. The circuit schematics is shown below.

This circuit is the same with the clock generator part of the voltage doubler circuit shown previously. Its only difference is that of its output frequency which is lower than that of the previous circuit. I have included a potentiometer or variable resistor into it to allow for adjustments of the output Duty Cycle or simply put the ration between the on time and the total period.

In summary the Alitaptap strobe light controller is a Fixed-Frequency-Variable-Duty-Cycle-NE555 Based Astable Multivibrator circuit.

Assembled it on a perforated board. The resulting circuit is shown in the following pictures.

The complete device, which is composed of the voltage doubler from, the Alitaptap strobe light controller and the LED strip, is shown in the following pictures.

Pictures of how I installed the whole device into my motor cycle will be posted later.

That's it for now.

Thank you for reading once again.