Bike Light Build: Part One

Just a few quick note about my latest project. I'm hoping to actually document this one in a useful manner, so bear with me. I've done a little bit of research about DIY lights for mountain biking and finally decided to get around to making one. Fall is upon us and soon there will be little to no chance that we will see the sun for months on end. I will therefor need something to light my path while biking.

I had considered going the cheap route of using a halogen light, but the run time is abysmal compared to other options, such as LED and HID. HID is simply stupid expensive, so I decided to go with an LED. After reading a website all about such lights here, I decided to go with a Cree MC-E emitter from ledsupply.com. The MC-E is actually four emitters closely packed together under one lens and it comes pre-mounted on an aluminum plate to help dissipate heat. The emitters are wired in series which means the forward voltages must be added together, resulting in a Vf of 12.8-13.2. The current is shared by the emitters and I will supply that with a Luxdrive Buckpuck with which I can provide a regulated 500 mA. I chose the wired model, with the potentiometer to vary the current from 0-100%.

To test the Buckpuck and LED I soldered some speaker wires that I scrounged from a box of stereo stuff I had in the closet. I put some alligator clips on those to aid in testing as well. I wired the Buckpuck to my regulated power supply and set the PS to 14.4V which is the voltage that I can get from two 7.2V Ni-Cd battery packs that I bought for my remote control car, when they are wired in series. I then attached the clips on the LED to the Buckpuck outputs and turned on the PS. Voila! Blinding frigging light. Seriously, don't look directly at this thing. At 350 mA this LED throws approximately 430 Lumens and I was driving it at 500 mA which should give it a 30% increase in flux. That is truly bright. I didn't leave the light on for long as it was not attached to any heat sinks and even an LED will heat up when driven at 6.5 watts. I just wanted to verify that everything worked anyway.

Next step... check to see how low a voltage this thing can be driven at so that I can be sure that the battery packs I have will work even when low, or if I need something with more than a nominal 14.4V.

Be vewy quiet, I'm hauling wabbit

I finally got around to hauling the Rabbit up to Maine for Jon to do some work on. It has been in Lee's barn for about 4 years now. In that that time it grew some mold on the interior and provided sanctuary for countless mice. Overall I think that is it very salvageable. Jon will put it on the lift and determine whether or not I am right. I didn't get a chance to try and start the bunny. Instead I scrubbed the mold off of the interior and vacuumed the mice nests out of the engine compartment and glove box. The battery was too far gone to even take a charge and I didn't have time to check the airbox to see if the mice had taken up residence in there as well. Jon will just have to do me the huge favor of doing that for me if he decides that it is worth the hassle.

I neglected to take pictures of the mouse nests, but below is a picture of the mold growing on the driver's side door panel.

I also didn't take pictures of the interior after I washed it, but it cleaned up pretty well. I used a mixture of water, bleach and dishwashing liquid. I wore a respirator while doing this too lessen the likelyhood of getting a respiratory infection. Hopefully it was worth the trouble. I'll post Jon's diagnosis as we go.

How to make waxed cloth

The wife found a project that she wanted to try doing and she enlisted my help, as usual. What she wanted to do was to make a product that she had seen online. The product was essentially cloth replacements for ziploc bags. These bags are to be waterproof, machine washable, and most importantly, pretty looking. Apparently, the products that she had seen had used a vinyl liner to waterproof them. As far as I know, vinyl is not a heathy substance to have near food as it offgasses formaldehyde. I informed her of this and she did some research to find alternatives. After shooting down all of the synthetic fabrics that popped up we decided on waxed cotton. Impregnating organic cotton with beeswax seemed like a very nontoxic and eco-conscious fabric to use.
I'm far too lazy to find the website where we found the instructions for impregnating the fabric with wax, but I will show here how it was done by us.


The first step is to cut a piece of craft paper, or a brown paper bag, and aluminum foil at least as long as the piece of cloth, and at least twice as wide. You want to be able to fold the foil and paper like a soft taco to with the foil and paper in lieu of tortilla, and the cloth and wax in lieu of delicious taco meat. MMMmmm tacos....


The next step is to evenly spread wax shavings on top of the cloth. We did this by using a crappy steak knife to scrape wax off of the big block and onto the cloth.


Next fold the taco... I mean foil and paper around the cloth and use an iron on medium heat to melt the wax. We found that if you go very slowly it gives the cloth time to soak up the wax and impregnates it more evenly. Quickly remove the cloth and allow to cool. Voila! Waterproof fabric that won't leach death into your food.

Up next... Adventures in sewing

This is a total sausagefest

I decided to make a kielbasa, since I know that my father in law likes it so much.  I used a recipe that I found online, but I made a few adjustments to it.  For one, I halved the recipe because ten pounds of sausage is a lot to make at once, especially if you’ve never made it before.  For another, I reduced

the water by a quarter of a cup and substituted a few ounces of brandy.  I also added a few tablespoons of paprika and I used collagen casings instead of natural casings so that my wife wouldn’t vomit when she saw them.  Also, Alton brown says that they are easier to work with, and what AB says is gospel in this house.

I’ve been wanting to try my hand at making sausage for a while now.  I even put a Kitchenaid meat grinder and sausage stuffer attachment on my wedding registry, much to the bemusement of my wife.  Whatever, she got a waffle maker and the Kitchenaid ice cream maker attachment, and I do 99% of the cooking.  I finally got around to actually making a batch of sausage today.  I promised my father in law and all of the other guys that I am going snowshoeing with next weekend that I would make some to go with the Belgian Dubbel I made, so I was committed to it. 

The Kitchenaid grinder attachment and sausage worked pretty well.  I did have a problem with the grinder plates getting clogged up.  I’m thinking that they clogged up with the connective tissue from the fat and rind.  I made a special effort to mix the fatty pieces in with the meat more thoroughly so that the meat could push the fatty pieces through, thus clearing the grinder plate.  It seemed to work pretty well, as I had no more clogs.  

Now there is just one more step to the sausage saga and that is smoking.  I got a stovetop smoker for X-mas and intend to use it to smoke the sausages on the trip this weekend.  I have not used the smoker yet so hopefully it works well.  The little bit of sausage that I fried up and tasted today was damn good, so smoking it sure as hell can’t hurt. 

Rebuilding a Digital Safe

 

I got a Mossberg digital hotel safe from work after it failed to function and we had to find a more creative way to open it.  From what I could see everything seemed to function alright so I assume the failure was one of the integrated circuits.  Regardless, I’ve decided that I want to rebuild it using an arduino.  The control board features a 16X2 LCD display and a 3X4 matrix keyboard.  Both of these should be fairly easy to get to work since there are arduino libraries available for them.  I just need to figure out how the hell to use the libraries.  That, and the little task of determining the pinouts on the LCD.

I downloaded the datasheet for the Hitachi HD44780A00 and then I used a continuity tester to find what pins went where.

 

The pinout seems to be pretty straight forward.  I will probably use a 4-bit LCD library due to the fact that the arduino has only 14 digital Input/Output and there simply wouldn’t be enough pins for an 8-bit configuration plus a 3X4 matrix keyboard, and the two limit switches and motor that are used to lock the safe. 

The keypad itself was pretty simple to determine it’s pinout as all of the traces on the circuit board are easy to trace by eye.  It turns out that the top three pins are for the rows, from top to bottom, and the remaining four are the columns, from right to left.

Test of Windows Live Writer

Testing…

I saw a post on lifehacker.com about Windows Live Writer, so I decided to give it a try.  So far it seems to be easier to use than the Blogger interface which can be tedious and buggy.  For a free service Blogger is excellent, but if there is a way to improve it then I may as well try. 

Verdict:

The interface responds pretty quickly and there are some pretty nifty ways to manipulate photos such as the rounded corners on the pictures above.  The first time that I posted the text and picture above the text was nearly obscured by the photo.  It was simple to adjust the margins to fix that so overall I’d say that I’m pretty happy with it, in spite of it being a Microsoft product.

Dubbel Track Kegged

I finally got around to kegging the Dubbel Track Ale this weekend. The original gravity was around 1.065 according to the Northern Brewer website from which I bought the ingredient kit. I'm not sure if it came out to be exactly that as my hydrometer was broken when I brewed the beer, so I'll have to trust Northern Brewer. I purchased a new hydrometer and measured the final gravity to be 1.011. Using the instruction that came with the the hydrometer this indicates that the alcohol content to be approximately 7-7.5% by volume. Using the formula ABV = (OG -FG)*131 that I found on the Beeradvocate.com I narrowed it down to 7.074%. I hope that this doesn't indicate that the beer didn't fully ferment because the ABV was supposed to be around 7.5%. I tasted it after I kegged it and it was pretty good, so I guess that it all that really matters.

Really Bare Bones Board Build

I purchased an RBBB(Really Bare Bones Board) from Modern Device Company quite some time ago and I never quite got it to work right. The RBBB is a VERY minimalist version of the Arduino which is easy to put on a solderless breadboard. The kit cost $7 but you have to solder it together, including some very small components, so it can be chalenging if you are new to soldering, and damn near impossible if you have a crappy Radio Shack soldering iron. I had purchased a $150 Weller iron prior to the build, so I had nothing but inexperiance and lack of skill to blame for my troubles.

I actually managed to get the more difficult components soldered on without a problem but I somehow managed to overheat one of the pads on the pcb and I lost a connection to ground because of that. The board would work it was positioned just right such that the pad made contact, but it failed more often than not.

Tonight while working on the Xbees I decided that I should finally get around to fixing this so I came up with a rather inelligant, yet effective solution. While it is difficult to see in the photo, The pin that has the bad connection is the ground pin that I soldered the Pin 13 LED to. I must have spent too much time heating that pad up because I was trying to mount the LED to it. Regardless, my rather hoaky fix was to solder a wire onto the to of that pin and stuff the other end of that wire into the DIP socket of the corresponding AVR pin. I checked the continuity with my multimeter and lo and behold it worked without needing me to wiggle the pin until it could chance upon a connection. I proceeded to check the rest of the leads and found them all to be working, so perhaps I'll actually get to use the RBBB for a project sometime in the future.

Xbee Communication Part 1: Getting Started

I have spent my free time in the past few days playing with Xbee wireless modules. I move at a snail's pace because I'm terrible at managing my time effectively. I did manage to get the two modules to communicate. Not bad for like three intermittent hours of work. I spent a few celebratory minutes typing messages between the two before I decided to start making dinner.

The first step to working with the Xbees, aside from ordering the parts from Sparkfun.com, was to solder the breakout boards and wire the circuits up on breadboards. I managed to miss the recommendation that you purchase the 2mm sockets with the breakout board so that you can change the Xbee modules at a later date so I ended up soldering them directly to the breakout boards.

I also purchase a logic level converter from Sparkfun in order to step down the voltage of the serial data lines from the arduino to the Xbee from 5V to 3.3V. I had to solder header pins on this as well, but the SMD chips were already on the PCB so I didn't have to do the painstaking work of soldering those tiny things on myself.

I ran into a few problems getting the Xbees to respond to my serial commands. The first problem was that I seemed to have the TX and RX lines reversed. I could have sworn that they we wired as the diagram in Making Things Talk showed, but my mind often wanders from the page to the breadboard, so I could have been wrong. The second problem was just the fact that I had multiple serial terminals open at the same time. This resulted in some error messages or the terminals simply not responding at all. Personally, I prefer the error message, even if I didn't bother reading it.

I chatted with Lee about the problem at work and he told me about the conflict with multiple serial terminals and I was able to fix the problem as soon as I knew to only do one at a time. Now that I have the two talking I need to figure out a project where they might be useful. I'm sure that I'll think of something eventually. At least I've taken the first baby steps though.

Driving a unipolar stepper with the Arduino

I decided to get around to playing with the Arduino again. I had a few unipolar stepper motors laying around so I decided that it was about time that I figured out how to interface them with the Arduino. The first hurdle was figuring out how to wire the motors. All three of the steppers are five wire unipolar, but none of them have wires. They all have PCB's with connectors on them. I had a connector or two that I took out of an HP printer so I just had to figure out which wire did what.

Finding the center tap on the motors was easy enough as you do so by using an ohmmeter to check the resistances between pairs of wires. The common power wire will be the one with only half as much resistance between it and all the others. Finding the order of the remaining four wires in the end required good old fashioned trail and error.

When I finally figured it out I made sure to label the wires. The wiring order worked on all three steppers, two of which are Mitsumi's and the third is a Minebea.

It was easy enough to get the stepper to turn once the wiring order was determined. The Arduino stepper library provides a pretty simple method of doing so. The Arduino website gives adequate instruction on figuring out how to use it so I won't bother documenting it again. I just figured that it might be helpful to post a picture of the wiring order that I found to be shared among the steppers that I have so that I may spare someone else the effort of figuring it out in the future.