QtDMM

QtDMM is a great GUI interface to Digital MultiMeters that have a computer interface. It has a few bugs, but these can be worked around.

Build

It is very important that you build it correctly from source. You need to turn off the FORTIFY flag checking in gcc. See Compiler Flags FORTIFY.

You will also need qt3-dev-tools. Unpack the tarball. Set the QTDIR environment variable! The following is for building under Ubuntu, but other distros are probably not much different:

aptitude install qt3-dev-tools
QTDIR=/usr/share/qt3/ ./configure BASECFLAGS=-U_FORTIFY_SOURCE
make

Radio Shack DMM Model #22-812

I use a Radio Shack Model #22-812. I'm not normally a fan of anything from Radio Shack, but this meter is inexpensive and it has a very useful RS-232 serial interface.

Under QtDMM: Preferences find the Multimeter settings section. I use the following settings:

Port: /dev/ttyUSB Bits: 8 Parity: None Stop bits: 1 Baud rate: 4800 Digits: 4000 Protocol: 9 bytes binary, continuous (RS 22-812)

import and export bug

Import and export of test data does not work perfectly. You can export the data, but it screws up the recorded data by saving every sample with the same date-time stamp -- and without fractions of a second which is critical since you can sample every 100 milliseconds. This is not so much of a problem since you at least know the time between samples which is good enough for graphing.

ZMeter alternative

An alternative to QtDMM is ZMeter.