Intermittent EV

A few months ago I was cruising along and my EV suddenly lost power. It was like someone had pushed in the clutch. I lifted the bonnet but the problem seemed to have gone and off I went again. Then it happened again last week. I suspected the throttle pot, as I . . . → Read More: Intermittent EV

Busting Teenage Partying with a Fluksometer

On New Years Eve 2011 I was in Geelong at a restaurant, 800km from my home in Adelaide. This year I happened to be away from my children, who were staying elsewhere in Adelaide while I was interstate. My home was supposedly vacant. However I knew it was very hot in Adelaide . . . → Read More: Busting Teenage Partying with a Fluksometer

linux.conf.au (LCA) 2012

Well, it’s that time of year again – my annual geek-week at linux.conf.au. Every day there were many interesting talks to attend and many I had to miss. I am currently catching the ones I missed by watching the LCA 2012 videos.

Keynotes and Open Source DSP

The Bruce Perens keynote had many good points on . . . → Read More: linux.conf.au (LCA) 2012

28,000 Electric km

I haven’t written much about my EV for a while as nothing much has happened. It just goes and goes, and has just clocked over 28,000 electric km since it was converted. This post is a collection of notes from my EV driving in 2011.

It’s been two years since I installed Lithium batteries and . . . → Read More: 28,000 Electric km

Codec 2 at 1400 bits/s

I’m in the process of releasing a 1400 bit/s version of Codec 2. Through efficient quantisation of the LSPs I have reduced the bit rate from 2500 to 1400 bit/s with only a small change in quality. This bit rate makes the codec very useful for digital voice over HF radio channels.

Here are . . . → Read More: Codec 2 at 1400 bits/s

My IP04 hacked and SIP ALG

Well this is a bit embarrasing. I make and sell embedded Asterisk boxes. My IP04 has been hacked! Some one made a bunch of calls to Guyana, among other places:

Call Summary

Destination
Calls
Amount

Algeria – Mobile Orascom
1
$0.39

Algeria – Mobile Wataniya
1
$0.59

Australia – 13/1300
2
$0.52

Australia – Adelaide
14
$1.82

Australia – Mobile
2
$3.18

Cape Verde – Mobile
1
$0.34

Cayman Is – Mobile C&W
1
$0.21

Dominica
1
$0.27

East Timor
1
$0.50

Guyana – Mobile
47
$16.91

Ireland – . . . → Read More: My IP04 hacked and SIP ALG

Driving the Nissan Leaf

Yesterday I took part in a Green Zone Drive event and had a test drive in the Nissan Leaf in the Mebourne CBD. I attended along with Michael and John, of the 3 Day EV fame. Also present were some other low emission vehicles and the Mitsubishi MIEV.

Our guide for the drive in the . . . → Read More: Driving the Nissan Leaf

Writing as Therapy

It’s been a long time since I last blogged. I have been dealing with some big personal problems since March and haven’t had time for technical work or the will to blog on anything. I have however been doing a lot of private writing or journalling. So I would like to talk a little . . . → Read More: Writing as Therapy

Simple Low Pass Digital Filter Design

For the $10 ATA DC-DC converter I need to design a low pass filter so that the discrete time model matches the real world DC-DC converter hardware. Given the time constant (tau), and the sampling rate Fs, I want to work out a value for c in the DC-DC converter discrete time model. In . . . → Read More: Simple Low Pass Digital Filter Design

Microwave Design and Why Experience Matters

I recently helped out debugging the Wifi on another AR2317 router project. This is the same SoC chip as the Mesh Potato, so I was revisiting the same Wifi debug territory as 18 months ago.

Turns out this board had the same major bug as we found in the Mesh Potato – the reference clock crystal . . . → Read More: Microwave Design and Why Experience Matters