Arbitrary Waveform Generator Reverse Engineering
A while back I picked up an ETC M631 Arbitrary Waveform Generator for $5 at a hamfest. The seller knew it worked, but had not used...
04 February 2021
Tagged: hack
F-Script Injection in Mavericks
I continue to use F-Script occasionally to investigate how programs work internally. The framework itself has been updated to handle the changes in OS X Mavericks. However, the developer tools included with Xcode 5 swap out the gdb debugger for lldb, breaking the injection script again. After playing around with the automator action some more, here's what I came up with that works on Mavericks.
14 August 2014
Scalar Network Analysis with a Spectrum Analyzer
A spectrum analyzer is a phenomenally useful piece of test equipment when working on RF circuitry. While used, several generation old spectrum analyzers can be found fairly reasonably priced, network analyzers are usually out of reach for a home lab. However, with a little bit of additional equipment some of the measurements that would normally require a network analyzer can be done on a spectrum analyzer.
11 July 2014
Fluke Scopemeter Optical Interface
I finally got around to building an optical interface so I don't have to use the hack I came up with previously to take screenshots or capture waveforms anymore.
19 November 2013
Fluke Scopemeter 97 Screenshot Hack
While waiting for parts to arrive to build a proper optical serial interface, I really wanted to get some screenshots off of my oscilloscope. Knowing that the infrared LED in the interface is directly transmitting the serial signal, I figured I should be able to tap into that driving signal to obtain the serial information.
12 February 2013
Fluke Scopemeter 97 EL Backlight Repair
I have a Fluke ScopeMeter 97 that's come in really handy over the years. Before I got it, it was a sales rep's demo unit, so it was used pretty hard. The screen backlight is an electroluminescent panel, and their intensity can fall off pretty dramatically over it's life. This particular display is also transflective, which makes it extremely readable under direct sunlight, but means the backlight is essential to using it in indoor lighting. To use it in the past, I'd shine a bright desk light on it, but I've always wished the backlight would just work.
12 February 2013
F-Script Injection in Lion
I wanted to use the very handy F-Script environment to snoop around inside an application. F-Script can be injected into running applications by using gdb, which of course works fine, but they also provide a services-menu item for performing the injection. Due to several changes in OS X 10.7 Lion, the automator workflow that came with F-Script to perform this did not work.
I reworked the injector service so it works on Lion and doesn't leave behind (or even create) any temp files.
21 May 2012
Georeferencing Trail Maps for PDF Maps on iOS
When I first got an iPhone, one of the first app ideas I had was one that would let me take a trail map image, mark a few known coordinates, then use the GPS to display the blue dot like in the built-in Maps app. I've searched for something similar a few times, and had actually started doing some research into libraries for doing the math. This weekend, I thought I'd search one more time, and there was actually a free app recently posted called PDF Maps by Avenza.
12 September 2011
HP LaserJet P1102w Firmware Update on Mac
Update: as of the last few versions, the standard HP firmware updater appears to be working fine on the most recent OS X versions. What follows is now strictly of academic value.
I have had an HP P1102w printer for over a year now.
I've had no complaints about it so far, but a firmware update was recently released that adds AirPrint support, allowing printing from iOS devices.
The problem is: the firmware updater refuses to do anything on OS X (at least in 10.6.8 and 10.7.x).
I searched but was never able to find a solution that worked.
So, I did what any normal person would do: I loaded it up in gdb.
18 August 2011
Optical Mouse Sensor Experiments
I had a cheap optical mouse sitting around where one of the wires had broken, and wanted to do something with it, so I tapped into the sensor!
06 October 2007
