Tag: linux

Bubbler: Monitoring homebrew CO2 production using arecord and Python

Posted by – 2012/02/08

A couple of weeks back I was thinking about monitors and sensors and had a crazy idea: it ought to be possible to gather stats on how well my plonk is fermenting by attaching a mic to the airlock and counting the bubbles. So in a moment of enthusiasm I ordered a cheap lapel microphone from eBay and forgot all about it… until Saturday morning when it finally arrived in the post.

Time for some fun!


TEMPer1 temperature sensor in Linux

Posted by – 2012/01/15

Yey! Just got my PCSensor TEMPer1 USB thermometer logging in Linux. It automatically detects and does expose USB HID profiles, but there’s no way to access the data by holding down the CAPS key like it says in the docs.

Thankfully, a search for the device ID (0c45:7401 Microdia) finds ruby bindings for Temper.c by Michitaka Ohno, which conveniently includes the reverse-engineered USB protocol. So I’ve forked this on GitHub, removed the Ruby bits, edited the unit test wrapped it up in a little script that logs the time and temperature to a CSV file. It currently only supports one device, which will change if I ever get another one of these devices (spoiler: I probably will)


Import vmstat logs into LoadRunner

Posted by – 2010/11/15

Here’s a little script to format vmstat’s output into something you can import into LoadRunner’s analysis tool:

import sys, time
                 "Proc Run,Proc sleep,"
                 "Mem swap use,Mem free,Mem buffered,Mem Cache,"
                 "Swap in,Swap out,Blocks in,Blocks out,"
                 "Interrupts,Context switches,"
                 "CPU %User,CPU %System,CPU %Idle,CPU %Wait,CPU %Stolen\n")
for line in iter(sys.stdin.readline, ""):
    if line[0] != 'p' and line[0:2] != ' r':
        t = time.strftime("%d/%m/%Y,%H:%M:%S", time.localtime(time.time()))
        line = ' '.join(line.split())
        line = line.replace(" ", ",")
        sys.stdout.write("%s,%s\n" % (t, line))

(Thanks to fabrizoM for the help!)

Run it from a shell script like so:

vmstat 5 | python vmstat2csv.py >> servername-vmstat.log

Then start the job from the shell, press CTRL+Z and nohup it (so it doesn’t die if you disconnect) and tail it (so you can keep an eye on it) like so:

[1]+  Stopped                 ./log.sh
[gaz@box ~]$ bg
[1]+ ./log.sh &
[gaz@box ~]$ disown
[gaz@box ~]$ tail -f servername-vmstat.log
Date,Time,Proc Run,Proc sleep,Mem swap use,Mem free,Mem buffered,Mem Cache,Swap in,Swap out,Blocks in,Blocks out,Interrupts,Context switches,CPU %User,CPU %System,CPU %Idle,CPU %Wait,CPU %Stolen

When you’re done, import it into the Analysis tool via the Tools -> External Monitors menu. Make sure you set the correct date for the custom format and remember to keep a close eye on the timezones. If you make a mistake while importing there’s no going back, so save a backup of your analysis files before you attempt this.