by rjones3 on March 22, 2013
I wanted my own breakout for the popular I2C TMp102 temperature sensor (Sparkfun breakout here) with a Molex Sherlock connector. The 4 pin connector would cover GND, V+, SDA, and SCL. I included a two-way solder jumper from the microbuilder Eagle library since I didn’t need all four I2C addresses. This switches the ADD0 pin from V+ or GND (0×48 or 0×49 respectively). The tricky bit is that the package pitch is 20 mil. I destroyed one package in an attempt to solder it by hand. Since I still lack a reflow oven or hot air gun, I used a Benzomatic torch with a heat gun attachment. If it’s stupid and it works, it’s not stupid! By far the smallest package I’ve ever worked with, and getting a good hot air rework station is still on my wishlist. I took an okay photo through an 8X eye loupe:
Stay tuned for a very boring post about how to crimp Molex Sherlock connectors!
by rjones3 on January 22, 2013
OSH Park is new to me, so I decided to try them out by fabricating two quick boards: a breadboard power supply and a 10W 50 Ohm dummy load. Click for more.
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by rjones3 on November 25, 2012
During my week-long Hurricane Sandy power outage I depleted all the off-grid power I had available, including my UPS Cyberpower CP1500AVRLCD, for charging the cell phone and HT. I eventually had to resort to charging stuff in the car and my town’s warming center. Since this was “a pain,” I decided to get a solution for the next long term power outage. Since I live in an apartment, a generator is not an option. I also can’t use the cheaper wet cell lead acid batteries because I lack a ventilated space to get rid of the hydrogen. These restrictions led directly to finding a sealed lead acid battery in adequate capacity, as well as a charger. I purchased a 35 A-h UPG UBCD5745 from Amazon since the price was right ($63.70 including shipping). The datasheet may be found here. Click for more.
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by rjones3 on August 26, 2012
I have been shaving for the past two years with a Merkur Progess DE razor and a Tweezerman shaving brush. I designed a laser-cut walnut shave stand to hold both of these which I finished with three coats of water-based clear polyurethane. Design files and more details after the break. [click to continue…]
by rjones3 on August 24, 2012
I made this recently for a friend using some extra room on a Ponoko sheet. It doesn’t really do anything. Maybe you could use it to hold keys? Anyway, I used Inkscape to trace my image using the bézier tool (shift+F6). I then edited the path by nodes (F2), with either adding or subtracting nodes as needed for details. It was a little tedious to do, but more accurate than the trace bitmap function. It was also helpful to make the source image a little transparent for tracing. More after the break. [click to continue…]
