It’s been a while since we’ve seen one of these. [vscd] sent in the flikr stream showing off the gorgeous MB-6582, built by [wilba]. It’s a diy midi synth that’s based on the midibox platform. It uses … synth chips to do the dirty work, and some PICs, a little CMOS hardware and a C64 PSU. He even anticipated some future versions of the midibox project to complete the design. This is one of the nicest DIY builds I’ve seen in a while – just beautiful work. Check out the build notes on the wiki page.

At first glance, [sprite_tm]s weller mod seemed a bit trivial. In reality, it’s like art with analog electronics. He wanted to add an indicator light for the heating element. To pull it off, he built a funky diode capacitor circuit to create a pseudo-regulated DC voltage, then used a zener diode, a potentiometer and a transistor to make a simple voltage switch that activates a transistor driven LED.

I was poking around the lumenlab forums and ran across this nice little project. It’s designed specifically for diy projectors. I settled for a simple thermal switch for my cooling, but this provides temperature monitoring/protection, dual fan control, lamp hour counter, serial interface and optional LCD controls. Everything you need to build your own is there, but it’s mostly in german.

Now I’m outta here – I’m going scuba diving.

Last year a friend of mine was kind enough to watch me jump out of a perfectly good airplane. While pondering that incredible adrinaline rush, I thought it was time for an altimeter hacking extra. (Don’t answer your phone for at least 12 hours after the jump or you might accidentally tell your mom…. Even if you’re 30 and in another state, you’ll probably get yelled at.)

The 2004 KAP rig on this page caught my eye. It features a small dongle that logs altimeter data when the shutter is activated on the camera. Schematics are in the pdf. The rest of the setups are pretty freakin’ impressive too.

Of course, there’s the classic model rocket altimeter project. If you’d prefer to leave off the cost of a basic stamp, try the more recently updated recording altimeter. It’s got a nice low parts count.

If you want something a bit more versatile, check out this RF transmitting altimeter. It’s still in progress, but it’s getting a thorough writeup as it progresses.

We’ve seen them before, but I’d be remiss not to mention a GPS data logger. (I took my old garmin foretrex on my skydive, but didn’t have a decent signal until I was out of the plane.

If someone finds a diy audible altimeter, let me know.