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SDrive NUXX PCB Assembly Complete

Published April 25, 2009

Sixteen of the assembled SDrive NUXX PCBs. They have all passed initial testing and are ready to be inserted into enclosures.

After working on and off for a week and a half, I have finished assembling most of the SDrive NUXX PCBs. It turns out that I’m missing a voltage regulator and DB25 connector, but I was still able to get 17 boards fully completed and two more missing only one component each. (The table pictured above contains more boards than shown, but I cut some off to better frame the image.)

Each board has also passed initial testing (100% success rate), which involves checking for shorts, checking voltages, checking LEDs, checking the buttons, and ensuring that the microcontroller can read the SD card. I’ll do more testing later, to be sure that booting an 800XL, running an app, doing R/W, and all that other important stuff works.

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Another Odd Whisker (Spiral)

Published April 25, 2009

Odd, spiral shaped whisker removed from my face one morning.

Here’s another odd whisker removed from my face, in the shape of a spiral. As happens occasionally I had a small ingrown-looking whisker, and upon pulling on it with tweezers (and expecting another abnormally thick whisker) this came out.

I would have liked to get a better photo of it, but as it’s only about 2mm long this was the best my 100mm 1:1 macro lens could do. This is the sort of thing that a microscope with a camera mount would be ideal for.

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Mud!

Published April 25, 2009

Very muddy Bianchi D.I.S.S. after a ride through Stony Creek and River Bends. All the mud came from the two-track or paved trails and not single track.

After last night’s ride around Stony Creek and today’s jaunt through River Bends, my bike is nicely muddy. Interestingly, all of the mud on there came from two track flooded paved trails and not any of the single track.

Now that I’m home I just have to sit around a while longer until I stop sweating, shower, and shave. Two bike rides in my legs are a bit filthy, and I’m sure there’s quite a stink coming from my various regions.

Later today should be interesting, because there are straight line wind / tornado-type weather coming. Looks like it’ll be here in about two hours. This could get exciting. Good thing I’ve got a bunch of stuff to do in the house.

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Sunset at Stony Creek

Published April 25, 2009

Sunset at Stony Creek, seen from the West Branch Parking Lot A, after a nice evening of riding.

Last night I met up with some friends at Stony Creek to ride the mountain bike trails there. Since I’m having problems with the rear wheel of one bike I brought my single speed with its new 2:1 gearing. This was a really nice, casual ride around all the single track once, then another run through The Pines for, as Kristi put it, “dessert”.

Surprisingly, I found this to be a really nice gearing for riding there. Because I’m familiar with the trail, hill climbs were difficult but not terrible. Nor did I spin out (get to a point where I can no longer pedal fast enough to keep the freewheel engaged) on flatter parts where I need to build up speed for upcoming hills.

All in all, I think this is a nice gearing for trails that I’m more familiar with. I think that after I finish eating some breakfast I’ll head over to River Bends and ride around a bit there before the forecasted thunderstorms roll in.

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Broken Spoke, Again!

Published April 22, 2009

I’m not happy. Today as I was preparing my bike for a ride tomorrow evening and commute on Friday morning I fitted the Continental TravelContact tires that I prefer for pavement riding. As soon as it was all together I took the bike for a quick ride around the parking lot to check for problems when I started hearing something odd out of the rear wheel. Pulling back into the garage and checking the trueness of the wheel I found that another nipple is broken and my wheel is now rather out of true.

This really disappoints me. The wheel was just taken to Fraser Bicycle and Fitness who supposedly fixed the other nipple and checked the wheel over and trued it. Since that I’ve ridden it only 50 miles or so, none of it being particularly rough offroad.

In order to deal with this I think that my next project after the SDrive NUXX will be to build a wheel truing stand and build myself a set of wheels. Brass nipples, nice spokes, decent rims, and decent hubs will hopefully result in something excellent. Also, this way if anything goes wrong I know that I’m to blame and where things may have gone wrong.

Now, to figure out what to do about the current nipple… I guess I could try sorting that out myself. It’s almost tempting to buy new spokes and nipples then disassemble and rebuild my existing wheels. As long as the rims aren’t trashed (which they shouldn’t be) that’d sort them out nicely. Presuming I do a good job, of course.

Maybe I’ll just ride the single speed in the mean time.

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NetOptics Passive 10/100 Ethernet Port Aggregator Tap Disassembly

Published April 20, 2009

Top/front view of the NetOptics Passive 10/100 Port Aggregator Tap.

Today I received a rather nifty device, an older-model Passive 10/100 Ethernet Port Aggregator Tap (PA-CU) from NetOptics. This device allows one to monitor both halves of a full-duplex 10/100 network connection at once, with only one capture device, which is rather nifty.

It was delivered quite early this morning by FedEx, and upon opening the box I saw that it was practically new, with the power supply shipping bags still sealed. There was no documentation, but this was easy enough to find online, and only consists of jumpers whose settings are silkscreened on the top of the enclosure.

After trying it out today I decided that it would be good to open it up and see what is inside. As this photo shows it is basically their older PCI aggretator tap repackaged into a rather nice metal housing. This board contains a FPGA, a bunch of SRAM, a PIC, and some currently unidentified (but well heatsinked) processors.

If you’d like to see more photos of the inside of the tap, they are all available here: NetOptics Passive 10/100 Ethernet Port Aggregator Tap.

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TiVo HD Power Supply: Fixed

Published April 19, 2009

Broken traces / board in a friend's Tivo HD power supply, model ST7002-BW0G.

Question: How long will a defective power supply (model ST7002-BW0G) last in a TiVo HD?

Answer: Just until the parts warranty expires.

Yesterday some friends of mine dropped their TiVo HD (TCD652160, manufactured 11-Jan-2008) off at my house so I could try and figure out why it wouldn’t power on correctly. It was reported to me that tapping various parts of the power supply would make it power on and off intermittently, so I set to look at why this happened.

When removing the board from the chassis I’d noticed that the substrate appeared cracked around a central screw hole, but an initial check on the copper side of the board showed that this damage didn’t extend through the metal. However, after reproducing the problem and finding it isolated to the 5V and 12V rails, I flipped the board over and found that the crack ran all the way to the edge of the board, severing a few traces in the process.

This was fixed by removing (scraping) soldermask as needed and soldering salvaged resistor leads (from here, specifically) across the gaps. This, plus the extra solder surrounding the lead, should make for a nicely permanent fix. The fixed PCB can be seen here, from a different angle than the above image. After the fix was put in place flexing the PCB on the bench nor pressing / tapping on it while installed in the housing caused the power to glitch.

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32:16 (2:1)

Published April 19, 2009

Sixteen-tooth Shimano freewheel (SF-MX30 16T) installed on a Surly hub on the rear end of my Bianchi D.I.S.S. single speed.

Today I finally got around to installing the Shimano SF-MX30 16T freewheel on the Bianchi D.I.S.S., replacing the 18T that was there. This takes the gear ratio from 32:18 (1.778:1) to 32:16 (2:1), which should be nice for flatter single track stuff where I’d end up practically spinning out. Hill climbs may be difficult, but hopefully I’ll still be able to make it. If I can’t I guess I can just go back to the 18T.

Since a threaded rear hub is required to use a freewheel like this, I’m tempted to get a track cog and lockring to try it as a fixed-gear mountain bike. This could go very, very wrong, though.

While fitting the freewheel I ended up cleaning up the drivetrain, washing the chain in solvent and then re-lubricating it. After the winter riding it was pretty grimy and needed a bit of work. After cleaning it up I tried out the Park Tool CC-3 which, as can be seen here, nestles into the chain to show if it is beyond 0.75% or 1% stretched. As the 0.75% side didn’t fit into the chain, it’s just fine to continue using.

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Leads To Trim

Published April 19, 2009

Leads from the resistors, crystal, and diode sticking out of the back of the production SDrive NUXXs. Time to trim these before fitting the capacitors.

After fitting the crystal, diode, and all resistors to eighteen SDrive NUXX PCBs there are lots of leads to trim before I can move on to the capacitors. Here is the pile of cut leads.

Leads are trimmed in batches as eventually there are enough sticking off the board that they get in the way. Next comes the capacitors, LEDs, and DIP switches before flux is cleaned off and the non-washable parts are fitted.

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Assembled SDrive NUXXs In Progress

Published April 16, 2009

Nineteen SDrive NUXX PCBs being assembled.

After assembling the first SDrive NUXX v1.1 (Production) PCB and ensuring that it worked as expected I started assembling the other eighteen PCBs. I only managed to get the SD slots and DIP28 sockets fitted before calling it an evening, but it’s coming along nicely. Hopefully by the end of the weekend I’ll have a good bit more done.

It’s really nice to have a final / complete PCB which doesn’t require any jumpers or other hacks to work.

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