User:Larz

Current Projects

Raspberry pi

This was delivered a few weeks ago. I've got it running with the standard Debian squeeze distribution.

I've finally got it running Wifi 802.11n. That was a struggle. There is a lot of misinformation going through the forums about power problems and wireless networking adapters. In the end, the only problems I encountered were buggy USB support.

It's serving SSH and VNC. I'm having fun logging into it from my phone and showing off to my workmates.

Aeroquad - Arduino Quadcopter

I've been playing with this on and off for the past two years.

It's a four rotor electric "helicopter" with an arduino board as the brains, 3 axis gyroscope, accelerometer, magnetometer sensors, a barometric sensor. It has room for GPS and SONAR as well.

I use a moderately hacked 2.4GHz radio for remote control, and a 900MHz XBee radio for telemetry & tuning.

Every other month or three, I drag it out and crash it, hence I've played with a vide variety of frames, motors, and props.

elektor Embeded Linux system (aka GNUBLIN)

Just got this little beauty. It is tiny, simple, and looks to be a lot of fun (once I figure out what I want to do with it).

Prior Projects

Heathkit GR-4000 Projector Television

This was a six foot diagonal silver screen projection TV. It had three large CRTs (Red/Green/Blue). It was a nightmare to keep the three guns converged. Every time you turned it on, the set was cold, and it projected three slightly offset images. You would tweak the geometry with a dozen little knobs, then watch for an hour. As the set warmed up, the electronics drifted. You would have to tweak it during the adverts!

The projector was a big wooden box that sat in the middle of the room, about 2 meters away from the screen. If the lights were dim, and you didn't look too closely, you'd think you were at the cinema! All this for only $1800 too.

High Power Rocketry Electronics (telemetry, staging, recovery deployment)

I am TRA-Tripoly Rocketry Association Level II certified in the USA.

I flew my perfect certification flight in Wisconsin, USA. It was a Public Missiles Phobos with a 35mm, J3500 composite motor. I flew my own flight computer based on the Intel 8051 running with an accelerometer and barometer. The rocket made 50g, 1.2 Mach, and just touched the 8000 feet (2438m) ceiling imposed by the FAA. The parachute deployed at apogee and the rocket landed about 700m from the launchpad. A perfect flight!

Amateur Radio

I received by HAM radio license in the USA back in 1998. (KB9SZH expired)

I've built a number of interesting antennae. I'll need to revisit this when I build a video rig for my quadcopter. I'd like to try a 5GHz skew-planar wheel or cover leaf antennae for this.

Fun Toys

Dlink DNS320 NAS

Nice looking little £50 Linux box with and ethernet port and two ESATA slots. A simple little hack/feature lets you load Debian packages onto it.

I use mine as a media streamer and backup server.

Netgear Powerline Ethernet

Project Idea: Put these chips into some projects.

Past Computers

TRS-80 (Z-80)

This was my first true hack.

In 1978, the TRS-80 only displayed upper case characters. This was done to save one chip. With only 7 RAM chips in the video circuit, the system was limited to displaying the first 128 characters of the character ROM.

I piggy-backed a 1K x 1 ram chip (that's 1024 bits - 2021A) onto the character generator circuit to allow all 8 bits of the character ROM to be accessed. A toggle switch on the side of the case let you turn the mod on and off. Not bad considering I was 14 years old and the machine cost $600.

Molecular SuperMicro 70-32 (17 x Z-80s & 8086)

Boo-YAh!