Martin's Atelier
Articles grouped by subject
AArduino
Although the Arduino is very convenient, I wanted to build my own from parts you can buy from RS or Farnell. Rather than cloning the Arduino, I took the opportunity to make some changes: I removed the USB/Serial interface because I've got a ICSP programmer, but added crude support for dual AA battery support. The AA cells suggest a good name: the AArduino!
Martin Oldfield, 22 Jun 2011
ADSL
Controlling things over Ethernet, here a hung ADSL modem, with the PIC Mini Web from Olimex. This is more of a brief sketch, to test the blogging software, than anything too deep or insightful.
Martin Oldfield, 16 Jun 2010
adt74x0
Analog Devices make some nice I²C temperature sensors, including the ADT7420 which is accurate to 0.25̣̣°C. Here’s a user space client for them.
Martin Oldfield, 05 Apr 2013
Agilent
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
apple
A recipe for apple cake.
Martin Oldfield, 16 Jun 2010
AppleScript
Importing tasks into OmniFocus
A simple command line program for importing tasks described by a YAML document into OmniFocus.
Martin Oldfield, 24 Oct 2010
Arduino
How to compile Arduino code from the command line.
Martin Oldfield, 19 May 2013
Although the Arduino is very convenient, I wanted to build my own from parts you can buy from RS or Farnell. Rather than cloning the Arduino, I took the opportunity to make some changes: I removed the USB/Serial interface because I've got a ICSP programmer, but added crude support for dual AA battery support. The AA cells suggest a good name: the AArduino!
Martin Oldfield, 22 Jun 2011
MacOS X and the Olimex AVR-ISP500
How to make the Olimex AVR-ISP500 work on MacOS 10.5.6: install version 1.005 of the firmware.
Martin Oldfield, 22 Jun 2011
I find it hard to remember the options I need when calling avrdude, but I don't know enough to work them out reliably every time. So, here's my handy cribsheet.
Martin Oldfield, 16 Jun 2010
ARM
Getting an ARM toolchain on MacOS 10.6
I'm starting to play with ARM microcontrollers, and building a toolchain is a necessary step. Here's a log of my experiences.
Martin Oldfield, 16 Jun 2010
Atmel
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
avahi
Being rather cheap little animals, Raspberry Pis tend to proliferate, and before long it’s hard to keep track of them all. Naming them helps, and software can make that more efficient.
Martin Oldfield, 04 Apr 2013
AVR
MacOS X and the Olimex AVR-ISP500
How to make the Olimex AVR-ISP500 work on MacOS 10.5.6: install version 1.005 of the firmware.
Martin Oldfield, 22 Jun 2011
AVR-ISP500
MacOS X and the Olimex AVR-ISP500
How to make the Olimex AVR-ISP500 work on MacOS 10.5.6: install version 1.005 of the firmware.
Martin Oldfield, 22 Jun 2011
I find it hard to remember the options I need when calling avrdude, but I don't know enough to work them out reliably every time. So, here's my handy cribsheet.
Martin Oldfield, 16 Jun 2010
avrdude
I find it hard to remember the options I need when calling avrdude, but I don't know enough to work them out reliably every time. So, here's my handy cribsheet.
Martin Oldfield, 16 Jun 2010
bars
Some brief notes on places to drink in Paris.
Martin Oldfield, 22 Oct 2012
Places to eat and drink in Copenhagen
Some brief notes on places to eat and drink in Copenhagen.
Martin Oldfield, 15 Dec 2010
batteries
Although the Arduino is very convenient, I wanted to build my own from parts you can buy from RS or Farnell. Rather than cloning the Arduino, I took the opportunity to make some changes: I removed the USB/Serial interface because I've got a ICSP programmer, but added crude support for dual AA battery support. The AA cells suggest a good name: the AArduino!
Martin Oldfield, 22 Jun 2011
bonjour
Being rather cheap little animals, Raspberry Pis tend to proliferate, and before long it’s hard to keep track of them all. Naming them helps, and software can make that more efficient.
Martin Oldfield, 04 Apr 2013
bus pirate
Self-help notes on using the bus pirate on MacOS—mainly links to other documentation.
Martin Oldfield, 16 Jun 2010
cake
A recipe for apple cake.
Martin Oldfield, 16 Jun 2010
California
Some brief notes on places to eat in California.
Martin Oldfield, 17 Sep 2012
Church Numeral
Fun and games with Church numerals in Haskell.
Martin Oldfield, 29 Mar 2011
command line
How to compile Arduino code from the command line.
Martin Oldfield, 19 May 2013
Watchdog: automatically do things when files change.
Martin Oldfield, 02 Jan 2013
Copenhagen
Places to eat and drink in Copenhagen
Some brief notes on places to eat and drink in Copenhagen.
Martin Oldfield, 15 Dec 2010
D2FC-F-7N
Replacing a Logitech Mouse Button
How to fix a dodgy button on a Logitech mouse: the key was finding a replacement for the Omron D2FC-F-7N.
Martin Oldfield, 07 Feb 2012
Debian
I have a bunch of virtual Debian machines on a Xen box. When they were installed I used etch, but I've just moved one domU to lenny: here's my crib sheet. I suspect it won't be generally useful.
Martin Oldfield, 16 Jun 2010
electronics
A simple PIC-based coordinate decoder for geocache puzzles.
Martin Oldfield, 04 Apr 2013
A simple intervalometer driven by a PIC microcontroller.
Martin Oldfield, 29 Dec 2012
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
Although the Arduino is very convenient, I wanted to build my own from parts you can buy from RS or Farnell. Rather than cloning the Arduino, I took the opportunity to make some changes: I removed the USB/Serial interface because I've got a ICSP programmer, but added crude support for dual AA battery support. The AA cells suggest a good name: the AArduino!
Martin Oldfield, 22 Jun 2011
A simple Perl script to generate blank stripboard templates.
Martin Oldfield, 16 Jun 2010
ethernet
Controlling things over Ethernet, here a hung ADSL modem, with the PIC Mini Web from Olimex. This is more of a brief sketch, to test the blogging software, than anything too deep or insightful.
Martin Oldfield, 16 Jun 2010
Flash
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
Garmin
Faking geocaches in Garmin GPX files
Garmin GPS receivers have a special mode to handle geocaches, but it's not been clear to me how the gadget decides which waypoints are geocaches. These brief notes describe something which works for me.
Martin Oldfield, 16 Jun 2010
gcc
Getting an ARM toolchain on MacOS 10.6
I'm starting to play with ARM microcontrollers, and building a toolchain is a necessary step. Here's a log of my experiences.
Martin Oldfield, 16 Jun 2010
geocaching
A simple PIC-based coordinate decoder for geocache puzzles.
Martin Oldfield, 04 Apr 2013
Helpful links for geocaching: particularly puzzle solving.
Martin Oldfield, 21 Oct 2012
A short program to find caches which are described in English. Very handy when caching abroad!
Martin Oldfield, 24 Oct 2010
Faking geocaches in Garmin GPX files
Garmin GPS receivers have a special mode to handle geocaches, but it's not been clear to me how the gadget decides which waypoints are geocaches. These brief notes describe something which works for me.
Martin Oldfield, 16 Jun 2010
gpsbabel
In practice I find that the tracklogs stored by my Garmin GPS receiver are quite noisy. gpsbabel easily filters the data, but having forgotten the relevant rules once, I thought I'd document them here.
Martin Oldfield, 16 Jun 2010
GPX
Faking geocaches in Garmin GPX files
Garmin GPS receivers have a special mode to handle geocaches, but it's not been clear to me how the gadget decides which waypoints are geocaches. These brief notes describe something which works for me.
Martin Oldfield, 16 Jun 2010
In practice I find that the tracklogs stored by my Garmin GPS receiver are quite noisy. gpsbabel easily filters the data, but having forgotten the relevant rules once, I thought I'd document them here.
Martin Oldfield, 16 Jun 2010
Haskell
A simple PIC-based coordinate decoder for geocache puzzles.
Martin Oldfield, 04 Apr 2013
Although Haskell is a fine language for hard-core programming, it’s increasing my tool of choice for trivial arithmetic too.
Martin Oldfield, 02 Jan 2013
Fun and games with Church numerals in Haskell.
Martin Oldfield, 29 Mar 2011
I2C
Analog Devices make some nice I²C temperature sensors, including the ADT7420 which is accurate to 0.25̣̣°C. Here’s a user space client for them.
Martin Oldfield, 05 Apr 2013
Intervalometer
A simple intervalometer driven by a PIC microcontroller.
Martin Oldfield, 29 Dec 2012
Brief notes on making time-lapse movies with a DSLR camera.
Martin Oldfield, 13 Aug 2011
Lake District
Places to eat in the Lake District
Some brief notes on places to eat in the Lake District taken on a trip in September 2008.
Martin Oldfield, 16 Jun 2010
language model
A short program to find caches which are described in English. Very handy when caching abroad!
Martin Oldfield, 24 Oct 2010
I wanted a toy language model so that I could write software which would identify the language of text.
The motivation for this is simple: given a list of geocaches, which ones have descriptions which I can understand!
Martin Oldfield, 16 Jun 2010
Linux
Aidés-memoires for configuring WiFi on a Raspberry Pi.
Martin Oldfield, 04 Apr 2013
logging
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
Logitech
Replacing a Logitech Mouse Button
How to fix a dodgy button on a Logitech mouse: the key was finding a replacement for the Omron D2FC-F-7N.
Martin Oldfield, 07 Feb 2012
London
Some brief notes on places to eat in London.
Martin Oldfield, 04 Mar 2013
MacOS
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
I just bought a new Mac and installed Xcode 4 on it. However, I couldn't build any Perl modules with XS (bits of C) in them. Here's a solution!
Martin Oldfield, 22 Jun 2011
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
MacOS X and the Olimex AVR-ISP500
How to make the Olimex AVR-ISP500 work on MacOS 10.5.6: install version 1.005 of the firmware.
Martin Oldfield, 22 Jun 2011
Self-help notes on using the bus pirate on MacOS—mainly links to other documentation.
Martin Oldfield, 16 Jun 2010
Makefile
How to compile Arduino code from the command line.
Martin Oldfield, 19 May 2013
I find it hard to remember the options I need when calling avrdude, but I don't know enough to work them out reliably every time. So, here's my handy cribsheet.
Martin Oldfield, 16 Jun 2010
measurement
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
Microchip
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
minty boost
Although the Arduino is very convenient, I wanted to build my own from parts you can buy from RS or Farnell. Rather than cloning the Arduino, I took the opportunity to make some changes: I removed the USB/Serial interface because I've got a ICSP programmer, but added crude support for dual AA battery support. The AA cells suggest a good name: the AArduino!
Martin Oldfield, 22 Jun 2011
Moment of Inertia
The tetrahedron's a simple solid, but its moment of inertia isn't in the usual tables, so I thought I'd calculate it. There are two calculations here: one's straightforward but long, the other's short and cunning.
Martin Oldfield, 15 Apr 2011
Calculating the moment of inertia of sphere. Overlong in itself, but hopefully a fine preliminary to the related calculation for a tetrahedron.
Martin Oldfield, 12 Apr 2011
Some basic facts about the moment of inertia
Martin Oldfield, 12 Apr 2011
Mouse
Replacing a Logitech Mouse Button
How to fix a dodgy button on a Logitech mouse: the key was finding a replacement for the Omron D2FC-F-7N.
Martin Oldfield, 07 Feb 2012
MPFS2
Recent versions of Microchip's TCP/IP stack (after version 4.11) use a new filing system and web server: MPFS2 and HTTP2. Microchip supply a Windows program, MPFS2.exe to manage things, but this is quite inconvenient for people on Linux or OS X. These Perl programs try to help.
Martin Oldfield, 16 Jun 2010
MySQL
Unicode games with perl, MySQL, and XML
Not for the first time I wasted a few hours getting Unicode things to 'just work' in a Perl project which mixed XML and MySQL. Hopefully these notes will prevent another repetition.
Martin Oldfield, 22 Jun 2011
Nixie
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
NMEA
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
NTP
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
Olimex
MacOS X and the Olimex AVR-ISP500
How to make the Olimex AVR-ISP500 work on MacOS 10.5.6: install version 1.005 of the firmware.
Martin Oldfield, 22 Jun 2011
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
OmniFocus
Importing tasks into OmniFocus
A simple command line program for importing tasks described by a YAML document into OmniFocus.
Martin Oldfield, 24 Oct 2010
Paris
Some brief notes on places to drink in Paris.
Martin Oldfield, 22 Oct 2012
Some brief notes on places to eat in Paris.
Martin Oldfield, 22 Oct 2012
patch
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
Perl
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
I just bought a new Mac and installed Xcode 4 on it. However, I couldn't build any Perl modules with XS (bits of C) in them. Here's a solution!
Martin Oldfield, 22 Jun 2011
Unicode games with perl, MySQL, and XML
Not for the first time I wasted a few hours getting Unicode things to 'just work' in a Perl project which mixed XML and MySQL. Hopefully these notes will prevent another repetition.
Martin Oldfield, 22 Jun 2011
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
Recent versions of Microchip's TCP/IP stack (after version 4.11) use a new filing system and web server: MPFS2 and HTTP2. Microchip supply a Windows program, MPFS2.exe to manage things, but this is quite inconvenient for people on Linux or OS X. These Perl programs try to help.
Martin Oldfield, 16 Jun 2010
A simple Perl script to generate blank stripboard templates.
Martin Oldfield, 16 Jun 2010
Photography
Brief notes on making time-lapse movies with a DSLR camera.
Martin Oldfield, 13 Aug 2011
PIC
A simple PIC-based coordinate decoder for geocache puzzles.
Martin Oldfield, 04 Apr 2013
A simple intervalometer driven by a PIC microcontroller.
Martin Oldfield, 29 Dec 2012
The tools I use when playing with PIC microcontrollers
Martin Oldfield, 16 Jun 2010
Recent versions of Microchip's TCP/IP stack (after version 4.11) use a new filing system and web server: MPFS2 and HTTP2. Microchip supply a Windows program, MPFS2.exe to manage things, but this is quite inconvenient for people on Linux or OS X. These Perl programs try to help.
Martin Oldfield, 16 Jun 2010
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
Controlling things over Ethernet, here a hung ADSL modem, with the PIC Mini Web from Olimex. This is more of a brief sketch, to test the blogging software, than anything too deep or insightful.
Martin Oldfield, 16 Jun 2010
PostScript
A simple Perl script to generate blank stripboard templates.
Martin Oldfield, 16 Jun 2010
probability
On of the Internet's recurring memes is a world where families have children until they have a son, then stop. There seems to be a fairly common misapprehension that this will lead to some asymmetry of sexes in the next generation.
This short note explores this question: we quickly see that symmetry is preserved, but then spend time exploring what's going on in more detail.Finally we introduce a new element to the model which, on its own, favours neither boys nor girls, but allows social engineering to skew the sex distribution.
Martin Oldfield, 30 Mar 2011
I wanted a toy language model so that I could write software which would identify the language of text.
The motivation for this is simple: given a list of geocaches, which ones have descriptions which I can understand!
Martin Oldfield, 16 Jun 2010
Raspberry Pi
A tiny library to interface cheap TM1638 displays to the Raspberry Pi.
Martin Oldfield, 20 May 2013
Analog Devices make some nice I²C temperature sensors, including the ADT7420 which is accurate to 0.25̣̣°C. Here’s a user space client for them.
Martin Oldfield, 05 Apr 2013
Being rather cheap little animals, Raspberry Pis tend to proliferate, and before long it’s hard to keep track of them all. Naming them helps, and software can make that more efficient.
Martin Oldfield, 04 Apr 2013
Aidés-memoires for configuring WiFi on a Raspberry Pi.
Martin Oldfield, 04 Apr 2013
Links I found useful when starting to play with the Raspberry Pi.
Martin Oldfield, 04 Apr 2013
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
A useful cable to connect the GPIO port to a breadboard.
Martin Oldfield, 31 Jul 2012
recipe
At a recent dinner party, one of my guests couldn't eat starch. This didn't seem compatible with my desire to serve tiramisu, but happily the lure of creamy coffee proved enough of an inspiration to find a solution: instead of coffee soaked sponge use coffee jelly.
Martin Oldfield, 16 Jun 2010
A recipe for apple cake.
Martin Oldfield, 16 Jun 2010
restaurants
Some brief notes on places to eat in London.
Martin Oldfield, 04 Mar 2013
Some brief notes on places to eat in Paris.
Martin Oldfield, 22 Oct 2012
Some brief notes on places to eat in California.
Martin Oldfield, 17 Sep 2012
Places to eat and drink in Copenhagen
Some brief notes on places to eat and drink in Copenhagen.
Martin Oldfield, 15 Dec 2010
Places to eat in the Lake District
Some brief notes on places to eat in the Lake District taken on a trip in September 2008.
Martin Oldfield, 16 Jun 2010
starch free
At a recent dinner party, one of my guests couldn't eat starch. This didn't seem compatible with my desire to serve tiramisu, but happily the lure of creamy coffee proved enough of an inspiration to find a solution: instead of coffee soaked sponge use coffee jelly.
Martin Oldfield, 16 Jun 2010
stripboard
A simple Perl script to generate blank stripboard templates.
Martin Oldfield, 16 Jun 2010
temperature
Analog Devices make some nice I²C temperature sensors, including the ADT7420 which is accurate to 0.25̣̣°C. Here’s a user space client for them.
Martin Oldfield, 05 Apr 2013
Tetrahedron
The tetrahedron's a simple solid, but its moment of inertia isn't in the usual tables, so I thought I'd calculate it. There are two calculations here: one's straightforward but long, the other's short and cunning.
Martin Oldfield, 15 Apr 2011
TF930
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
Time Capsule
One of my Macs recently died and I wanted to recover data from a Time Machine. Sadly this wasn't entirely trivial.
Martin Oldfield, 30 Mar 2011
Time Machine
One of my Macs recently died and I wanted to recover data from a Time Machine. Sadly this wasn't entirely trivial.
Martin Oldfield, 30 Mar 2011
Time-lapse
A simple intervalometer driven by a PIC microcontroller.
Martin Oldfield, 29 Dec 2012
Brief notes on making time-lapse movies with a DSLR camera.
Martin Oldfield, 13 Aug 2011
tiramisu
At a recent dinner party, one of my guests couldn't eat starch. This didn't seem compatible with my desire to serve tiramisu, but happily the lure of creamy coffee proved enough of an inspiration to find a solution: instead of coffee soaked sponge use coffee jelly.
Martin Oldfield, 16 Jun 2010
TM1638
A tiny library to interface cheap TM1638 displays to the Raspberry Pi.
Martin Oldfield, 20 May 2013
TTi
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
U1272A
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
UNI/O
A simple PIC-based coordinate decoder for geocache puzzles.
Martin Oldfield, 04 Apr 2013
Unicode
Unicode games with perl, MySQL, and XML
Not for the first time I wasted a few hours getting Unicode things to 'just work' in a Perl project which mixed XML and MySQL. Hopefully these notes will prevent another repetition.
Martin Oldfield, 22 Jun 2011
utilities
Watchdog: automatically do things when files change.
Martin Oldfield, 02 Jan 2013
watchdog
Watchdog: automatically do things when files change.
Martin Oldfield, 02 Jan 2013
WiFi
Aidés-memoires for configuring WiFi on a Raspberry Pi.
Martin Oldfield, 04 Apr 2013
Xcode 4
I just bought a new Mac and installed Xcode 4 on it. However, I couldn't build any Perl modules with XS (bits of C) in them. Here's a solution!
Martin Oldfield, 22 Jun 2011
xen
I have a bunch of virtual Debian machines on a Xen box. When they were installed I used etch, but I've just moved one domU to lenny: here's my crib sheet. I suspect it won't be generally useful.
Martin Oldfield, 16 Jun 2010
XML
Unicode games with perl, MySQL, and XML
Not for the first time I wasted a few hours getting Unicode things to 'just work' in a Perl project which mixed XML and MySQL. Hopefully these notes will prevent another repetition.
Martin Oldfield, 22 Jun 2011
zeroconf
Being rather cheap little animals, Raspberry Pis tend to proliferate, and before long it’s hard to keep track of them all. Naming them helps, and software can make that more efficient.
Martin Oldfield, 04 Apr 2013
Articles grouped by date
2013-05
A tiny library to interface cheap TM1638 displays to the Raspberry Pi.
Martin Oldfield, 20 May 2013
How to compile Arduino code from the command line.
Martin Oldfield, 19 May 2013
2013-04
Analog Devices make some nice I²C temperature sensors, including the ADT7420 which is accurate to 0.25̣̣°C. Here’s a user space client for them.
Martin Oldfield, 05 Apr 2013
Being rather cheap little animals, Raspberry Pis tend to proliferate, and before long it’s hard to keep track of them all. Naming them helps, and software can make that more efficient.
Martin Oldfield, 04 Apr 2013
Aidés-memoires for configuring WiFi on a Raspberry Pi.
Martin Oldfield, 04 Apr 2013
Links I found useful when starting to play with the Raspberry Pi.
Martin Oldfield, 04 Apr 2013
A simple PIC-based coordinate decoder for geocache puzzles.
Martin Oldfield, 04 Apr 2013
2013-03
Some brief notes on places to eat in London.
Martin Oldfield, 04 Mar 2013
2013-01
Watchdog: automatically do things when files change.
Martin Oldfield, 02 Jan 2013
Although Haskell is a fine language for hard-core programming, it’s increasing my tool of choice for trivial arithmetic too.
Martin Oldfield, 02 Jan 2013
2012-12
A simple intervalometer driven by a PIC microcontroller.
Martin Oldfield, 29 Dec 2012
2012-10
Some brief notes on places to drink in Paris.
Martin Oldfield, 22 Oct 2012
Some brief notes on places to eat in Paris.
Martin Oldfield, 22 Oct 2012
Helpful links for geocaching: particularly puzzle solving.
Martin Oldfield, 21 Oct 2012
2012-09
Some brief notes on places to eat in California.
Martin Oldfield, 17 Sep 2012
2012-08
A Nixie clock which gets its time from a Raspberry Pi pretending to be a GPS receiver.
Martin Oldfield, 19 Aug 2012
2012-07
A useful cable to connect the GPIO port to a breadboard.
Martin Oldfield, 31 Jul 2012
2012-02
Brief notes on reading data from a TTi TF930 3GHz counter from MacOS.
Martin Oldfield, 19 Feb 2012
Replacing a Logitech Mouse Button
How to fix a dodgy button on a Logitech mouse: the key was finding a replacement for the Omron D2FC-F-7N.
Martin Oldfield, 07 Feb 2012
2011-08
Brief notes on making time-lapse movies with a DSLR camera.
Martin Oldfield, 13 Aug 2011
2011-06
Although the Arduino is very convenient, I wanted to build my own from parts you can buy from RS or Farnell. Rather than cloning the Arduino, I took the opportunity to make some changes: I removed the USB/Serial interface because I've got a ICSP programmer, but added crude support for dual AA battery support. The AA cells suggest a good name: the AArduino!
Martin Oldfield, 22 Jun 2011
I just bought a new Mac and installed Xcode 4 on it. However, I couldn't build any Perl modules with XS (bits of C) in them. Here's a solution!
Martin Oldfield, 22 Jun 2011
Unicode games with perl, MySQL, and XML
Not for the first time I wasted a few hours getting Unicode things to 'just work' in a Perl project which mixed XML and MySQL. Hopefully these notes will prevent another repetition.
Martin Oldfield, 22 Jun 2011
Brief notes on reading data from an Agilent U1272A multimeter from MacOS.
Martin Oldfield, 22 Jun 2011
MacOS X and the Olimex AVR-ISP500
How to make the Olimex AVR-ISP500 work on MacOS 10.5.6: install version 1.005 of the firmware.
Martin Oldfield, 22 Jun 2011
2011-04
The tetrahedron's a simple solid, but its moment of inertia isn't in the usual tables, so I thought I'd calculate it. There are two calculations here: one's straightforward but long, the other's short and cunning.
Martin Oldfield, 15 Apr 2011
Calculating the moment of inertia of sphere. Overlong in itself, but hopefully a fine preliminary to the related calculation for a tetrahedron.
Martin Oldfield, 12 Apr 2011
Some basic facts about the moment of inertia
Martin Oldfield, 12 Apr 2011
2011-03
One of my Macs recently died and I wanted to recover data from a Time Machine. Sadly this wasn't entirely trivial.
Martin Oldfield, 30 Mar 2011
On of the Internet's recurring memes is a world where families have children until they have a son, then stop. There seems to be a fairly common misapprehension that this will lead to some asymmetry of sexes in the next generation.
This short note explores this question: we quickly see that symmetry is preserved, but then spend time exploring what's going on in more detail.Finally we introduce a new element to the model which, on its own, favours neither boys nor girls, but allows social engineering to skew the sex distribution.
Martin Oldfield, 30 Mar 2011
Fun and games with Church numerals in Haskell.
Martin Oldfield, 29 Mar 2011
2010-12
Places to eat and drink in Copenhagen
Some brief notes on places to eat and drink in Copenhagen.
Martin Oldfield, 15 Dec 2010
2010-10
Importing tasks into OmniFocus
A simple command line program for importing tasks described by a YAML document into OmniFocus.
Martin Oldfield, 24 Oct 2010
A short program to find caches which are described in English. Very handy when caching abroad!
Martin Oldfield, 24 Oct 2010
2010-06
Getting an ARM toolchain on MacOS 10.6
I'm starting to play with ARM microcontrollers, and building a toolchain is a necessary step. Here's a log of my experiences.
Martin Oldfield, 16 Jun 2010
The tools I use when playing with PIC microcontrollers
Martin Oldfield, 16 Jun 2010
I have a bunch of virtual Debian machines on a Xen box. When they were installed I used etch, but I've just moved one domU to lenny: here's my crib sheet. I suspect it won't be generally useful.
Martin Oldfield, 16 Jun 2010
Faking geocaches in Garmin GPX files
Garmin GPS receivers have a special mode to handle geocaches, but it's not been clear to me how the gadget decides which waypoints are geocaches. These brief notes describe something which works for me.
Martin Oldfield, 16 Jun 2010
In practice I find that the tracklogs stored by my Garmin GPS receiver are quite noisy. gpsbabel easily filters the data, but having forgotten the relevant rules once, I thought I'd document them here.
Martin Oldfield, 16 Jun 2010
Self-help notes on using the bus pirate on MacOS—mainly links to other documentation.
Martin Oldfield, 16 Jun 2010
At a recent dinner party, one of my guests couldn't eat starch. This didn't seem compatible with my desire to serve tiramisu, but happily the lure of creamy coffee proved enough of an inspiration to find a solution: instead of coffee soaked sponge use coffee jelly.
Martin Oldfield, 16 Jun 2010
I wanted a toy language model so that I could write software which would identify the language of text.
The motivation for this is simple: given a list of geocaches, which ones have descriptions which I can understand!
Martin Oldfield, 16 Jun 2010
Recent versions of Microchip's TCP/IP stack (after version 4.11) use a new filing system and web server: MPFS2 and HTTP2. Microchip supply a Windows program, MPFS2.exe to manage things, but this is quite inconvenient for people on Linux or OS X. These Perl programs try to help.
Martin Oldfield, 16 Jun 2010
The first article
Martin Oldfield, 16 Jun 2010
An easy way to patch recent versions (e.g. 4.16) of the Microchip PIC TCP-IP stack to work with the Atmel flash EEPROMs on Olimex boards.
Martin Oldfield, 16 Jun 2010
Controlling things over Ethernet, here a hung ADSL modem, with the PIC Mini Web from Olimex. This is more of a brief sketch, to test the blogging software, than anything too deep or insightful.
Martin Oldfield, 16 Jun 2010
A simple Perl script to generate blank stripboard templates.
Martin Oldfield, 16 Jun 2010
I find it hard to remember the options I need when calling avrdude, but I don't know enough to work them out reliably every time. So, here's my handy cribsheet.
Martin Oldfield, 16 Jun 2010
Places to eat in the Lake District
Some brief notes on places to eat in the Lake District taken on a trip in September 2008.
Martin Oldfield, 16 Jun 2010
A recipe for apple cake.
Martin Oldfield, 16 Jun 2010