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).

Future Projects

Modify ESC-Electronic Speed Controller

This will allow me to use I2C signaling rather than the standard PWM-Pulse Width Modulation to drive the motors on the quadcopter.

Add FPV-First Person Video transmitter and camera to quadcopter

This would allow flying in first person mode.

Add a transmitter and video camera on a stabilised gimbal to quadcopter

This is an RC controlled camera operated by second person, separate from FPV camera. The camera operator has their own control and video feed..

Prior Projects

2.4GHz, 9 Channel R/C Radio Hacking

My quadcopter needs to be controlled with a 9 channel digital radio. Instead of buying a top-end German radio for £300, I modified an inexpensive Turnigy radio that cost £95.

Added a USB programmer to allow reflashing the radio with modified firmware, backlit the display with a EL panel, and rigged up a LiPo battery pack to replace the NiMH battery pack.

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 with a Public Missiles Phobos rocket with a 38mm, J3500 composite motor. I flew my own flight computer based on the Intel 8051 running with an accelerometer and barometer. The rocket accelerated at 50g, reached a maximum speed of 1.2 Mach, and reached an altitude or 8000 feet (2438m), the flight 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 clover 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.

Dlink NSLU2 NAS

This is another little Linux NAS server. You can reflash the stock firmware with a modified file system and open the device up for all sorts of interesting uses. Here is a link to the NSLU2-Linux Community page.

Netgear Powerline Ethernet

Project Idea: Put these chips into some projects.

Past Computers

TRS-80 (Z-80)

This was my first proper mod.

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!