Algorithmic Composter

Inexpensive, home-scale computer controlled composter, buildable with recycled parts like washing machine motors and 40 gallon drums

Similar projects worth following
To benefit the environment (and our gardens) composting can keep food waste out of landfill.
But compost can be a tricky thing. Not enough moisture or too much prevent proper organic breakdown. Same for air. To help, the compost should be turned regularly. The soil temperature must rise, to accelerate decompostion, however we don't it too hot or concentrated. Too much methane in a confined space may be dangerous - alternatively we might try and harvest the methane for fuel...
To further help the environment, the design allows for construction with recycled parts such as commonly available 40 gallon drums, yet be simply assembled.
The Algorithmic Composter measures multiple variables and controls rotation of the drum and throughput of water and gases & allows remote monitoring and logging of compost state.
The Algorithmic Composter is the idea of my friend @spacebat, I am helping him get started

There are several components:

  • Drum, augmented with unwired sensors and actuators
  • Drum coupling, with hollow section for water inlet & exhaust, and positioning elements
  • Motor, motor controller & belt drive
  • A-frame
  • Control unit & wireless

This will be a mains or 12V powered unit depending on the kind of motor available.

To avoid slip rings, we are looking at a system like the wireless mobile charging systems, where the drum will intermittently rotate to a 'charge' position and charge the internal sensor and acutator harness. The sensors mounted on the drum will communicate with BLE to the control unit to save power.

There will be a simple lid on the side for adding waste material & ejecting compost

  • Circuit rough cut

    pastcompute03/30/2015 at 08:53 0 comments

    Two primary functions:

    • Detect and control motor speed, and detect and set position of barrel as a result
    • Read temperature humidity and gas and inject water and eject air/gas under algorithmic control

  • Get it down!

    pastcompute03/29/2015 at 11:55 0 comments

    So my friend @spacebat explained this idea to me in great detail about how we could use a computer to control the composting project, and I tried hard to persuade him that we should post it to hackaday. Anyway the current plan is to have a "hackathon" weekend in a months time, where we, together with my father in-law who is an awesome mechanical fabricator, we will see what we can cobble together.

    We already have 40 gallon drums, a dead washing machine with a working motor, an arduino, a welder, a soldering iron and willingness to experiment!

    In the meantime, background plan is to research algorithm development...

View all 2 project logs

Enjoy this project?



Jamie wrote 10/30/2016 at 14:42 point

Hey I just found this... Joined hackaday with the whole intention of putting my compost up... there are some similarities between your prototype and my design though I don't have things like a gas sensor. I do measure moisture and humidity and have it turn and water automatically but there are things I am still finishing out or working on. Cool ideas! 

  Are you sure? yes | no

pastcompute wrote 01/13/2017 at 12:03 point

Good luck ! We never progressed past the idea stage like so many things sadly. Too much things, not enough time...

  Are you sure? yes | no

sbi.gaijin wrote 06/25/2015 at 23:19 point

Motor-controller section... you probably want to rethink PWM output to the relay.  Either on/off  (relay) or PWM to an H-bridge driver to give speed and directional control.  The H-driver will make your recharging positioning easier.

  Are you sure? yes | no wrote 06/15/2015 at 13:45 point

What would you think of having a dozen or so small (golf ball) sized wireless sensors tossed in to the mix and churned up in order to obtain an overall picture of the conditions?  Check out my Garden Mill, we're working toward the same end, just from different angles.  In the gallery, the rendered image shows the water input as a small white pipe above the enclosure's opening.  Maybe we could join forces?

  Are you sure? yes | no

Moley Hackeral wrote 04/06/2015 at 05:00 point

That looks like a really cool project, and I've wanted to do something like this for a while, but just don't have the time!  :) 

Why all the wireless sensors, though?  Would it not be much easier (and robust) to wire the sensors in from the axle of the drum?  I can't imagine that you actually want to fix the sensors to the inside of the barrel anyway, since you probably don't want your gas sensor to end up at the bottom under the compost and your moisture sensor on top.

  Are you sure? yes | no

pastcompute wrote 04/07/2015 at 12:32 point

We are still working out the detail - but trying to avoid slip rings or cable tangles was one reason. The gas sensor(s) etc. would be mounted to the central axle as you suggested to be out of the soil, or even two on opposite drum sides, with a suitable cage / filter to keep the presently lower one being caged. Alternatively, the rotation would keep mixing the soil but the controller ensure always ending correct side up...

  Are you sure? yes | no

mr.jb wrote 03/29/2015 at 16:30 point

If I were to award the best invention ALL TIMES ( based on what it benefits the next generation ) it would be Terra Preta  - black earth a space roughly the size of France – or twice the UK.

The power of compost

  Are you sure? yes | no

Similar Projects

Does this project spark your interest?

Become a member to follow this project and never miss any updates