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.

Toolbox organization

I purchased a new Craftsmen tool chest to hold my ever expanding tool collection, as well as to free my old toolbox to use for bike specific tools. I was unhappy with the lack of organization on my old toolbox. Whenever I opened a drawer tool would roll around and get all mixed up, especially my sockets as they are round and roll quite efficiently.
The first step that I took in preventing tools from rolling and sliding was to line the drawers with something that had a non-slip surface. My toolbox had foam drawer liners but they didn't really have the grip necessary to do anything more than simply protect the paint of the toolbox. I found some Con-tact brand shelf liner at Home depot that claimed to be quite grippy and when I touched it I felt that it seemed much more promising than the liners offered by Sears.
I cut the liner using a utility knife and some flooring that was leftover from my basement remodel as a cutting guide. The flooring had a cork backing that made a nice cutting surface that didn't dull the tip of my knife, and it had a nice straight edge to guide the knife with.
After the drawers were lined(Except for one as I did my math wrong and didn't get enough liner. Doh!) I wanted to make sure that I had somethign to really prevent the sockets from rolling around. I remembered that I had some Komplement drawer divider in the garage that we had forgotten to return with the Hopen wardrobe that we assembled, only to find that our ceilings were are too short to fit it. I had to modify the drawer dividers to fit and to separate the multitude of different types of sockets that I have. I used a utility knife to do this. I feel as though a small hand saw would be much better for this, but I lack such a saw, so the utility knife was what I used. The most difficult part was cutting the notches that interlock the dividers in place. The dividers are thin plywood with three plys and the middle ply was difficult to get though with the knife, but I managed. All things considered, it came out pretty well. I do want to cut the height of the dividers that run horizontally in the shelf, in order to make it easier to get to the tools in the back of the drawer and to add some labels to let me quickly see what the sockets are in each compartment. Aside from that I'm pretty happy with the outcome.

Xmas present for my sister

My sister has said for years that she would ride a bike if I found her one with a banana seat. This year for Christmas I did just that. I happened to mention to my friend Lee that I was hoping to find such a bike to give to my sister and he happened to have one in his basement. Lee has one of everything, by the way. I did some research and determined that the bike was a Ross Barracuda, made in the late sixties to early seventies.
The bike needed a bit of work, but it was in pretty good condition overall. I disassembled pretty much everything, down to the wheel hubs, and cleaned, polished or replaced anything that needed it. I decided not to go to the effort of repainting the frame as the many little rust spots gave it character, in my opinion. The only things that I ended up buying, in addition to the bike, were a bottom bracket and tires. Luckily I found a bottom bracket at Harris Cycle and tires on Amazon. Whitewalls kick ass. Below is the "after" picture. I thought it came out pretty nice and my sister seemed to agree as she jumped up and down in the driveway as I unloaded the bike from the car.

Beer Label

One of my favorite parts of the homebrewing process has always been the design of the label. I've been using the program GIMP a bit at work lately so I figured that I'd get some more practise using(at work) by designing the label for the Belgian Dubbel. As you can see from the picture I have decided to name the beer "Dubbel Track Ale". If you couldn't figure it out from the picture, double track is a term commonly used to describe a dirt road or path in which there are two distinct parallel paths; typically worn by a atv's, trucks or tractors. These are the type of trails that we rode in Colorado in September, so this is a salute to my boys, who accompanied me on the trip.

Yay! Fermentation!

Quick followup on my last post; the beer it is fermenting. I checked last night when I got home from work and there was a slow bubbling in the airlock. That's just a bit more than 24 hours later which is not bad at all. I'm really looking forward to trying this one. I think that it is going to be super tasty.