Home-brewed time-lapse fungus growing 101

That last post was because I could hardly contain myself.  Messing about with hardware, scripting and growing things all on the same project was right u my street and I couldn’t resist.  I’m working my way up to producing a much bigger and high-res time-lapse project later this year, and this was something of a trial run.

The idea was simple…

1. Take a mushroom growing kit from gourmetmushrooms.co.uk
2. Use it to turn a fairly racist and crap novel (which upset me because it’s written in Robert Ludlum‘s name, and not half as good) into mushrooms
3. Eat them in a meal where I’d grown or made everything
4. Film the whole process and release the film and the scripts that built it.

The Mushrooms

The instructions that came with the kit are pretty good.  You soak the book in warm water, wring it out so it’s not sodden, scatter spore impregnated wheat through the book and then rubber band it up nice and tight.  It sits somewhere for a couple of days (about a week) until the mushrooms root system has developed and once the whole book has gone white you pop it in the fridge for a couple of days.  This shocks the mushroom system into growing, a bit like a cold patch of weather.

Once you take the book out of the fridge and open up the plastic bag it’s just a matter of keeping it warm and nicely moist.  A plant mister is perfect.  Spray a couple of times a day and you should be about right.  I went to a wedding for 2 days, so soaked it well before leaving and it survived ok.

Once sizable mushrooms had formed it’s justa matter of breaking them off and getting cooking.  With a bit of luck the book should produce another run, if not, it’s compostable (hell, it’s half way there).

The technology

The original plan was to use an old Sony laptop running Linux, connected by USB to a digital SLR camera, taking a photo every 15 minutes and backing these up.  After talks with Ken Murphy about his History of the sky project at MakeFaire this all sounded pretty easy.  However after a lot of messing about with gphoto2-lib and my old Fuji S7000 I found them to be incompatible, one could see the other, but not take photos. Bummer.  My Nikon D40x works with gphoto2 brilliantly, and takes better photos, but you can’t power it externally easily and the batteries only last for about 24 hours taking a photo every 15 minutes.

To top it all off, the laptop I had picked out turned out to not have an ethernet port (how old was it, no idea, 10 years +) , so it was back to the drawing board all round.

So ended up with the following rig…

1. My old G4 iBook running OS X
2. A webcam from PC World for a tenner (Logitech)
3. Wacaw running to take the photos
4. DropBox* being used for remove backup and public viewing
5. Cron calling
6. A bunch of BASH scripts to hold it together electronically
7. A bunch of duct tape to physically hold it together

Wacaw was a complete find and saved my bacon.  It’s a command line utility that will ket you call multiple cameras and save the images off that it gets back.  It did on Mac what gphoto2 was going to do for me on Linux.  You run it with a -L switch to get a list of available devices, and then run it again calling the input device you wish to grab from.  Ideal if you want to do multiple angles with multiple cameras.

The scripts that make al this happen are nothing special, just a bit of date wrangling to get a unique id for each photo, and then some copying around to ship the files to DropBox. A second script runs once a day to create a daily video file.

This first script captures a new image ever 15 minutes, between the hours of 5am and 7pm. Here’s it’s crontab entry

0,15,30,45  5,6,7,8,9,10,11,12,13,14,15,16,17,18,19 * * *  /Users/me/grabber.sh

And here’s the script…

#!/bin/bash
DTS=$(date "+%y_%m_%d_%H_%M")
HOME=/Users/me
#/Applications/wacaw -d02 /Users/${home}/Documents/grabs/one_${DTS}
/Applications/wacaw -d02 /Users/${home}/Documents/grabs/mushroom_${DTS}
rm ${home}/Documents/grabs/mushroom_current.jpeg
cp ${home}/Documents/grabs/mushroom_${DTS}.jpeg ${home}/Documents/grabs/mushroom_current.jpeg
cp ${home}/Documents/grabs/mushroom_${DTS}.jpeg ${home}/Dropbox/Public/mushrooms
cp ${home}/Documents/grabs/mushroom_current.jpeg${home}/Dropbox/Public/mushrooms

And here's the daily crontab entry that makes a film...

58 23 * * *  /Users/me/filmer.sh

#!/bin/bash
set -x
DTS=$(date "+%y_%m_%d")
/Applications/Mencoder\ OS\ X.app/Contents/Resources/mencoder "mf:///Users/me/Documents/grabs/mushroom_${DTS}_*.jpeg" -mf fps=10 -o /Users/me/Documents/grabs/${DTS}.avi -ovc lavc -lavcopts vcodec=msmpeg4v2:vbitrate=800
cp /Users/me/Documents/grabs/${DTS}.avi /Users/me/Dropbox/Public/mushrooms

And here are the results, which if you look closely, you can see that I picked them two days too late.

12 days of mushroom growing time-lapse from Oli on Vimeo.

Also, the photos (and the final destination)

*Disclosure: if you use the link for Dropbox on this page, you’ll get an extra 250mb and so will I because it’s a referral link.  I’ll not make any money through.

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• Jerking it
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