The Cause From the first day in my on-campus apartment, I have been plagued with wireless dropouts that seem to occur whenever I have to access the internet that is not leisurely related. My room, as I have deemed, is far enough away from the access point that the signal often vacillates between being, according to Microsoft Windows, “good” to “poor/ no connection”. One way to circumvent this is to take my laptop out into the living room that I share with my roommates; there are three of us with each having our own bedroom. I, being a lazy bum as well as the one who will not take things lying down, contemplated on a way to obtain a good wireless signal that will minimize packet loss. I have tried contacting the technology help desk and inquire about an access point, but that proved to be fruitless due to “security” concerns. Inspiration One of my roommates decided to buy a Linksys USB wireless transceiver that seemed to work really well. Packet loss and drop-outs were minimized to the point of almost being non-existent. Since I am an EE-major venturing forth into Pre-Med, I can not leave things well enough alone or helpless (my pride), I decided to “spice” things up a bit. I bought the same model as my roommate and proceeded to take in ideas of how to personalize the wireless adapter. After perusing several project logs and articles from Bit-Tech as well as other sites, I decided to go with my own favorite aesthetic choice: piano black with my favorite colors of blue and white. Specifications • The Linksys USB Wireless transceiver will be housed in a different container that is clear to be tinted with 5% from observing Macroblack’s mod. • A modified fan will be installed to cool the electronic components inside the clear box since power supply circuitry will also be present. • The USB connection from the transceiver to the computer will be made via Cat6 wire from a repeater since the length between the two is approximately 35 feet. • A VU meter that is often seen in audio applications will be integrated into the transceiver. This VU meter will be controlled via a PIC that is to be connected to the wireless electronics. • Fan speed control will be based upon a variable voltage regulator, from Cpemma’s site, that is to be user-controlled. • The transceiver will work off an external 12v power supply, wall wart, and will have digital logic to minimize the chance of one the transceiver being powered while the laptop is un-powered and vice versa. • TO BE CONSIDERED: An antenna replacement that will boost the ability of the transceiver to receive. Attributes and Design Translucent Case Size: 4.7" x 2.6" x 1.6" or 11.9cm x 6.6cm x 4.1cm Perspective View of the Unit (Not Drawn to Scale because I can not measure worth anything) Orthographic View of the Unit (Not Drawn to Scale because I can not measure worth anything) The cooling fan will be modified to have four blue LEDs that will be interfaced with a voltage regulator so the variable regulator that controls the fan will not dim the LEDs to a point. Utilizing Cpemma’s voltage regulator design, even a turn to the slowest setting will not throw off the regulation fed into the LEDs. The Activity Meter will be controlled via a PIC that has one of its input pins take inTTL-level logic from the Linksys’ Activity LED through a transistor. The program, that is to be written in assembly, will go through revisions to obtain the best effect for the given activity. The logic is laid out in the following flowchart. Fan Control will be, depending on circumstances, either transistor controlled or voltage regulator controlled. The power supply that is located in the unit will convert the 12v from the wall wart into a stable 5v rail via a linear regulator. The power supply will be logically controlled so that two true conditions must be satisfied in order for the rest of the circuitry to begin supplying power. The conditions that must be met are: (1) Does the unit/client have power? (2) Does the host have power? This is implemented to prevent the unit from sending data when the host is turned off. Much thought has been given to how the unit/client would survive if the host gave data while the client’s rails are off. Besides trying to purchase high speed tri-state buffers for a low price in a very small quantity, this question still remains until the beginning of its construction. Note: All planning is subject to change at an instant if deemed necessary. Discussion Log
Greetings, since this is technically not a project log without work... let the work commence! This is the Linksys Wireless Transceiver that I have purchased. I did not have the chance to photograph the original because of two reasons: I did not have a camera at the time and I am an impatient person. The first step of this mod is to void the warranty. I found out, after relinquishing the circuit board from the confines of the container, that the BGA chip in the Linksys becomes very hot after only a few seconds of power. I decided to immediately apply a BGA RAM heatsink with Artic Silver Thermal Adhesive since drilling holes would be a little harsh. I found a case, in my electronics supplies, that was ordered from All Electronics. The case, being clear, sparked my imagination to re-create Macroblack’s theme. I ordered from New Egg, a USB extender and a hard drive cooler that contained the 50mm fan that I needed to fit the dimensions of the case. I could have gone with a 40mm fan, but I would be trading for some space, that could be sacrificed, for a louder fan. My electronic components, some not pictured yet, have arrived. I started work on the fan since it is probably the easiest and most absent minded thing I would do, besides writing assembly, in this project. I proceeded to shorten the power tail and add your usual fan header to the fan. I must comment that I have the hardest time working with the female pins – I usually have to go through twice the amount needed. Time to do something I am not particularly fond of: Aligning and making modifications to the case. This requires measuring and several instances of anxiety followed by a plethora of cuss words. My poor attempt at trying to transform a regulator hackneyed fan into a… regular… hackneyed LED fan. I will work on the circuitry on a later time since a TO-92 cased voltage regulator would suffice. The case is already appearing to be suffering from insufficient space. Took some time to look over and test the USB extender to end the day and go do schoolwork. Next Time: Void the warranty of the USB extender, finish the fan and its associated circuitry, and make some more modifications to the case. Discussion Log
Project Log From the depths of my mind comes a new era, will actually it is just my first time; a new beginning, is that not like era; of the most breathtaking, actually you can breath normally; phenomenal, hey let us stick to simple words here that I can spell as well; creation of human kind, actually I think sliced bread was pretty up there. Anyway, just read the log and enjoy yourself. Subliminal Message Here Questions, comments, and occassional reality checks (you will be dealt with harshly), are welcome.
What tipe of antenna u choose for this mod? i think, if u use a rectangle of some metal, and bend it, to take a parabolic shape.
I am thinking about incorportating an actual Linksys Rubberduck antenna since I have seen, being in the EE-department, how much work goes into calculating/designing the strucure of an antenna that recieves a high frquency carrier wave and what is more efficient as well as non-interfering with other signals.
I have carried out the following so far to my project: This is during the testing stage of the fan’s circuitry. You can see that I am utilizing a voltage regulator to “regulate” the voltage down to about 3.75 volts (ideal world). This should allow the voltage, which is being fed to the LEDs, to be kept at a constant level provided that the control is regulating the voltage being fed to the fan and the voltage that is being fed to the voltage regulator is for LEDs is not thrown out of regulation from too low of a voltage input. Other variables such as temperature, moisture, catastrophic events, and so on are not taken into account. The following equation addresses the necessary calculations with regards to Iq being thrown out because of within the range of tolerance while traversing from the ideal world to the real world: Vout = 1.25(1 + [R2 + VR1] / R1) + Iq Vout = 1.25(1 + [2000] / 1000) Below illustrates a simple schematic for the fan’s LED circuitry: The resistor values for the LEDs are calculated as shown below: R = (Vs - Vl) / I 11.25 Ώ = (3.75 – 3.3) / 0.04 Nearest resistor is a 10 Ώ resistor. Fan with flash Fan without flash. The night shot comes later when the product is finished. The Linksys circuit board in the case; it looks to be a little cramped. Tiers will have to be utilized to accommodate the space issue. Oh yea, here is the picture of the naked, warranty voided, USB extender. I need to find a place to drill at least two holes to mount the board quasi-securely onto the case. The SMD on the board are taking up too much space. Next Time: Cut out the fan hole (cringe) and try to mod the USB extender (I might have to glue something onto the circuit board to avoid drilling holes into it). Discussion Log
Kumo: You read my mind about going that way. I am thinking, as well as the hot glue, of adding a backing to the jack since an insertion would likely break the bonds of the hot glue by itself.
This segment in the project involves a slight irreversible error that affects only the aesthetic view of the product. You will see what I am announcing from the following log. The worst part of the project is now in session: Cutting out a circle for the fan to “breath”. I began by drilling holes in a circular pattern following the outlined black sharpie. The drilling was followed by cuts on both sides of the holes within the outlined circle to remove most of the material This is the result of the cutting: (no mistakes so far) This was followed by sanding and shaping from a sanding drum attached to a Dremel to rid the area of unnecessary material. During sanding with the drum, my drum caught, for about one second, on a piece of acrylic and the combined force of my hand and the rotational friction melted more material than I had planned to destroy. Thus this is the reason the following picture depicts the fan hole with a slight aberration. After cussing under my breath, I proceeded to sand the inner edges of the circle with 400 and 1000 grit sandpaper to smooth the edges. The aberration still sticks out like a sore thumb. The time after the cutting out of the circle was spent designating an area to cut out of the box for the RJ-45 jack. This measurement was come by holding the USB-extender against the box’s side while placing a standoff in a small area where no traces or SMDs were located. At the same time, a sharpie was utilized to shakily draw a depiction of the cut out area. Yes, this is a very accurate and scientific way to do things. Some extra time was taken to fashion a power jack connector for the modulation of the power supply. I think it needs to be shorter though… Next Time: Cut out the jack port (swears), mod the USB-extender, mod the case, and setup the tier for the USB. Discussion Log
