This is a picture of our digital picture frame. It's an old old laptop (D300XT with 96 Megs of RAM) reversed and put into a shadow box. Right now it's running windows but ideally I want to convert it over the some Linux flavor a better picture viewer. It uses irfanview which works nicely and reads off of a network share. All the power and wires are behind it it in the wall. The otherside of the wall was a closet so it was easy to run the wires on that side. The nice thing about it is that it has a 1024x768 resolution.

Rat Grotto

This is a picture of the "rat grotto." I built this in about a day. We had one rat and were getting another rat to keep our one company and we needed a bigger place for him. I went to home depot and got a 15" x 96" melamine board and a 12" x 48" shelf cut it and screwed it together. I also got some thing 1/8" melamine for the back. We also cut the 1/8 melamine to fit on the shelf and we wedge the ends of a towel on both edges to hold the towel down, so when we need to change things around it's easy to get the towels up but still too hard for the rats to pull it up.

The doors are 2" pine with some green plastic coated screen dadoed in it. The whole thing probably cost around $50 or so to build and I've got left over 1/8" melamine (It came in a 3x7 sheet) and screen for other projects now.

So far it's a bit easier to clean then the cage we had. Anyway I just wanted to post a picture of this project.

GW Profile 4 power supply

When I got the Gateway Profile 4, it didn't come with a power supply so I had to fashion one myself. I didn't realize that it was a funny connector and 13.3 amp 12 volt supply. Fortunatly enough the connector is like the extra connector on computer power supplies. Also fortunately I had some extra power supplies. My first try didn't go so well. I didn't realize to run the 12 volt rail you need a load on the 5 volt rail or else you can burn out the power supply. So some internet searching later and I came up with what you see above. I didn't realize people modify these PSUs for battery chargers. I used a 10W 10Ohm resistor across the 5 volt leads and I zip tied it to the back of the case so the case can act as a heat sink. It doesn't seem to get hot at all. Also to fit the power plug I just cut off the retention clip off the extra 12 volt line and viola.

Helpful links
http://www.e-maxximumrc.com/html/power_supply.html

It's Alive!!!

Previously I had mentioned I got a Gateway Profile 4 at a surplus auction, it was cheap because it didn't work (Screen). After reading a bunch of websites I yanked the inverters and found a burned out transformer. After looking around ebay ($70 for a replacement), I was leaning towards a unversal LCD inverter solution ($25 from ebay) (http://pkrobot.freehostia.com/LCDRepair4.htm). I started emailing pk for more information how he did and he happened to have his old inverter and he was kind enough to send it to me. I had already yanked the bad transformer in a foolish attempt to fix it (Epoxy and really small wires, bad combination). I pulled a transformer off pk's inverter and put on mine and I now have a mostly fully working machine! Interestingly enough I bought this mainly for the parts and to find out it was only a inverter problem fueled my desire to fix it. Now I've got to back and find parts somewhere else. I had to build a power supply for this I'll post about this next time.

Valentines Day gift

I got inspired by this project link. But I was dissappointed by the lack of information on how to do it besides the use of a 74hc595. I embarked on trying to figure out out with a pic controller. I tried hc595s first and got it working (Above picture), then I tried the microchip 23016 but I got confused by the resistor and capacitor requirement (It was late that night and I didn't want to read the datasheet). I also had an old sample of the Maxim 7216 laying around and thought I'd give it a go and it seemed to work quite nicely. I used the 16f648a but it may have been overkill since my app only uses about 550 words, I could probably redo this on a 12f625 (Or is it 10f625) and have enough room for lots of scrolling animation.

I didn't really do any animations or anything with it yet because the one thing that attracted me to the project was the fact that it ran on a CR2032. I thought it would be cool. I just wanted to reduce the number of things I'd need to solder up and so forth. Ideally I wanted this for VDay but with that day quickly approaching and me without much time, I'm probably not going to get it done. Maybe her birthday. I patterned my picBasic code after some code I found (http://list.picbasic.com/forum/messages/4011/4341.html?1030122622). I modified it a bit but got it working pretty easily and I think if I reduce the resistor value I can get it to work with the little button battery (CR2032). If anyone is interested in the code I can send it, it's PicBasic Pro. Ideally I'd like to make a little PCB this could all fit on but my CNC isn't done and I don't enjoy the whole iron on etch method (I know it's not that hard but sometimes I'm lazy).

Here are some other sites that helped out
http://www.kronosrobotics.com/an137/DAN137.shtml
http://www.picbasic.co.uk/forum/archive/index.php/t-2244.html
http://www.maxim-ic.com/quick_view2.cfm?qv_pk=1339&t=do#Data%20Sheethttp://tomekness.files.wordpress.com/2008/01/max7219_tutorial_pre_c.pdf
MAX7219
http://www.ccsinfo.com/forum/viewtopic.php?t=17380&sid=87d2b2852119c3c64b603e1734

I am a sucker for a good deal. Recently there was a city auction for a Gateway Profile 4. They actually had two but I lost the auction for the second one. It was cheap because it didn't work. Looking it over I discovered it was the inverter. I wish I could have gotten the second one and parted it for this one. Anyway I've found a numer of sites that take about this (The inverter problem is a common problem with this).

Here are some sites I found that have been helpful
http://www.hardwareanalysis.com/content/topic/31540/?o=120
http://pkrobot.freehostia.com/LCDRepair4.htm
http://laptops-we-r.com/pblog/index.php
http://pkrobot.freehostia.com/LCDRepair5.htm
http://www.e-maxximumrc.com/html/power_supply.html

If fact these sites inspired me to start this blog. Anyway on my inverter I figured out it was the transformer. I pulled it out and the lead wire was burned out. I tried to solder it back but the lead to the wire was epoxied and my attempts to get a connection to it only led to a shorter and shorter lead wire. Sigh.

Above is a picture of the controller and power supply I have for a CNC machine I'm building. (Based on http://www.instructables.com/id/Easy-to-Build-Desk-Top-3-Axis-CNC-Milling-Machine/). I got the stepper controllers from sparkfun.com. I got the power supply from an old tape backup drive (I thought it would make a nice case and housing for the electronics). I din't have a picture of the CNC machine so far because it's been pushed off in the garage while I work on other projects. I have the X and Y access done but need to stiffel the lateral movement a little.

Things I learned: Bearings are expensive but I went to the Savers and found some used roller blades for $3 and got a bunch of bearings now. Also I didn't have plexi glass for the table and I used 1/4 melamine and it seems to be ok. I'll give more details of this project when I get back to it and can take some decent pictures.

This winter I came across a craigslist ad for a broken air hockey table. I had always wanted to build an air hockey table for my boys and I thought this would be a good opportunity to get some parts. What's the worst I could do? I mean it was already broken.

I didn't take any pictures before but when I got the table it had a crack going down the entire length of the playing field. Everything else on the table was fine except for this crack (It was about 1/8 to 1/4 inch wide). The crack also buckled the table a little so the playing field was lifted up abit.

After calling the manufacturer and getting a referal to another place, the cost of a new playing field would be about $700 shipped. So my strategy to repair the table was as follows.
1) Patch the table drill new holes in the patch, paint it and see if that works.
2) If that doesn't work route out the entire crack, expose the baffel and replace about a 2-3" area with something (Plastic?).
3) If that doesn't work, I can buy a new top, formica or thin luan. (Lot of holes to drill)
4) If that doesn't work (Last resort), build my own table top and try to replicate the baffels for good air flow.

As you can see from the pictures I got to step 1. It didn't work too badly except for the fact that the buckling was a little wider then I thought. I used a router that I put some little feet on and just used a trim bit (Couldn't find a planer bit) and when I was doing this, I felt like I was shaving a lot of material off but there was still a buckle (speed bump) on the table after all of this and the puck didn't go over this very easily (It easily got high centered).

Yesterday I thought I'd see if I could sand it smooth with a random orbital sander. It didn't do much except remove the paint job I did. So I think I need to find a better router bit and repaint. I think I'll try this before option 2 since option 2 is so invasive and loud and messy.

Couple things I learned. I read a bunch of forums about painting formica. I used some Zinzer primer, Krylon paint and an oil based semi gloss poly. The zinzer and krylon went on ok, excpet that I masked the area and when I pulled the tape of there was a little bump. Also when I spraid the poly, it caused some of the paint to crinkle. I probably did a bad job of surface prep, although I used TSP and alcohol to clean the sruface. Also I used spackle to fill the whole (I tried silicon but it dried too rough) and it seemed to shrink when I hit it with the primer.

Some other observations about this table. The playing field is 3/4 MDF with baffels criss crossed with what I think is a formica (Or some sort of plastic) top. The baffels appear to be about 3/8 deep (or less) with the criss crosses being about 3/16. and about 3/8-1/2" wide. If I remade the pplaying surface I think I'd just get some 1/2 MDF and make strips to glue on to another 1/2 MDF sheet instead of trying to route all those groves (Baffels) and glue on some formica or thin luan. The problem with this table field is that the baffels weaken the table a little, but I think the glued on formica give it a lot of strength (I still don't know how this table broke).