Hackaday Prize Entry: Smart Composting System

Composting serves an important purpose in our society, reusing our food scraps and yard waste to fertilize gardens rather than fill up landfills. Knowing that most people don’t compost, [Darian Johnson] set out to create a Arduino-controlled composting system to make it as simple as possible. It monitors your bin’s moisture, temperature, and gas emissions to ensure it’s properly watered and aerated.

[Darian]’s project combines a MQ4 gas sensor that detects combustible gas, a soil moisture sensor, and a temperature and humidity probe. The nearby water reservoir is monitored by an ultrasonic sensor that keeps track of the water level; a pump triggered by a TIP120 turns on the water. Meanwhile, a servo-controlled vent keeps the air flowing just right.

The Smart Composting System sounds like it would be useful to home gardeners; it’s a Best Product finalist in the 2017 Hackaday Prize.

Super-Sizing Leaf Collection; Hackers Doing Yardwork

For many parts of the world, the great raking has begun as deciduous trees in temperate zones drop their leaves. Of course not everyone can abide the simple yet laborious process of manual raking and so they look to technology. You can buy a handheld leaf vacuum, a pull-behind leaf sweeper, or a mower attachment that lifts leaves into hoppers. [Lou] has the latter, but it’s way too small for his taste so he super-sized his leaf collecting hardware.

The hard part of leaf collection has already been solved for [Lou]. The riding lawnmower lifts the leaves and propels them through an angled pipe into three hopper bags which we think total 9 bushels (roughly 80 gallons or 300 liters). That sounds like a lot, but anyone who has recently cleared leaves will attest that they will fill up in no time.

[Lou] builds a light-weigh 4-foot cube covered in deer netting to super-size his hopper to a whopping 51 bushels (475 gallons or 1800 liters)! His first attempt uses a pipe that falls too short to fill leaves to the top, but his final product adds longer ductwork and hits the mark perfectly.

Gardeners everywhere should be salivating right now. Leaf mulch is one of the best things you can put on your garden in the spring. Although [Lou] designed his hopper to be emptied by leaf-blower, adapting this to set the full hopper in an out-of-the-way space would help them breakdown over the winter — turning them into planter’s gold by springtime.

Continue reading “Super-Sizing Leaf Collection; Hackers Doing Yardwork”

Amalgamate is the Internet of Compost

A lot of people are scared of composting. After all, if the temperatures or humidity go badly wrong, you can end up with dried-out trash or a stinking soup. Getting the balance right is a secret known to the ancients: toss it in a big pile in your backyard. But what if you don’t have a big backyard?

Amalgamate is a composting setup for the urban dweller, or for people who just don’t like bugs. [Jamie] built it as her first Raspberry Pi project, and that makes it a great entrée into the world of things. But it’s no lightweight: the software measures temperature and humidity, and lets you schedule watering and rotating the compost. And of course, if you’re a micromanager, you can get up-to-the-minute vitals on your cellphone and tweak everything to run just perfectly. Continue reading “Amalgamate is the Internet of Compost”

Compost heap temperature logger helps keep things hot


HackHut user [lackawanna] is looking to start his own compost pile, but as many urban composters discover, things can get quite smelly if you don’t manage it properly. The process of composting is broken up into two phases, aerobic and anaerobic decomposition. The former is the first stage to occur and produces plenty of heat, but should be scentless. The latter gives off less heat and is more of a stink due to putrefaction. Carefully monitoring the temperature of the pile and restarting the aerobic phase when necessary helps to keep the process “healthy” and scent-free.

[lackawanna] built a simple temperature monitor that he plans on using to track the status of his compost pile once he gets started. It uses an ATmega328 as the brains of the operation and an old metal can transistor as his temperature sensor. Using relative measurements of the compost pile taken in 10 minute intervals, he can determine when the aerobic phase is underway, as well as when things begin turning anaerobic. At that point, the sensor alerts him that the pile needs to be turned.

The build is pretty simple, but leaves plenty of room for expansion. It should be relatively easy to add a more friendly notification interface as well as install multiple sensors to the pile for obtaining aggregate temperature data.

Composting to create hot water

Want nature to supply you with 130-150 degree hot water? [Onestraw] shows you how to get just that by building a compost heap that heats water. Finding himself the proud owner of a dump truck of green wood chips [Onestraw] went about building his own version of Jean Pain’s thermal compost pile. The idea is to produce and store methane generated from the compost pile but in order to do so, the temperature must be kept fairly low. The microorganisms in the compost generate a lot of heat trying to break down that matter and running water through the system will keep the temperature low enough for the methane-producers to be happy. The side effect of this cooling system is hot water coming out the other end. [Onestraw] even has plans to use salvaged car radiators to turn the hot water into a heating system for his home. Granted you’re not going to add this to your apartment, but if you have space and waste plant matter and need hot water this is a great way to get it.

[Thanks Joel]