kilnController

Turns a Raspberry Pi into a cheap, universal & web-enabled kiln Controller. Forked from the reflow oven project: picoReflow which I found through a blog post on succulent ceramics

​I used kilnController to add a firing schedule control to a little pottery kiln I picked up second hand. The kiln is 10A/240V rated to 1000 degrees C. It has a door switch and a basic thermostat which allows for 25%, 50%, 75% or 100% power but no timer, which means constant monitoring if you want to ramp the temperature up slowly or soak the wares at any point. With the kilnController I can now set it up for a bisque or low temperature glaze firing and leave it to its own devices, checking progress every now and then on my mobile phone or PC.

Standard Interface

Curve Editor

Hardware

• Raspberry Pi Zero W - any pi will do but the zeros are the cheapest at about $15 here in Australia
• MAX 31855 Cold-Junction K-Type Thermocouple (about $6 on eBay)
• K-Type Thermocouple Sensor -100°C to 1250°C ($3 on eBay)
• Solid State Relay Module SSR-25DA 25A /250V 3-32V DC Input 24-380VAC Output (again, about $6 on eBay)

Wiring

​MAX31855 to RPi PIN (Pin Name)

Vin not connected 3Vo to Pin 1 (3.3v DC) GND to Pin 9 (Ground) DO to Pin 11 (GPIO 17) CS to Pin 13 (GPIO 27) CLK to Pin 15 (GPIO 22)

Installation

Dependencies

External dependencies have been kept to a minimum to make it easily deployable on any flavor of open-source operating system.

Currently tested versions

• greenlet-0.4.2
• bottle-0.12.4
• gevent-1.0
• gevent-websocket-0.9.3

Ubuntu/Raspbian

$ sudo apt-get install python-pip python-dev libevent-dev
$ sudo pip install ez-setup
$ sudo pip install greenlet bottle gevent gevent-websocket

Gentoo

$ emerge -av dev-libs/libevent dev-python/pip
$ pip install ez-setup
$ pip install greenlet bottle gevent gevent-websocket

Raspberry PI deployment

If you want to deploy the code on a PI for production:

$ pip install RPi.GPIO

This only applies to non-Raspbian installations, since Raspbian ships RPi.GPIO with the default installation.

If you also want to use the in-kernel SPI drivers with a MAX31855 sensor:

$ sudo pip install Adafruit-MAX31855

Clone repo

$ git clone https://github.com/botheredbybees/kilnController.git
$ cd kilnController

Configuration

All parameters are defined in config.py. There's a copy in config.py.EXAMPLE so you can review and change things to your heart's content.

Usage

Server Startup

$ cd kilnController
$ python kilncontrollerd.py

Autostart Server onBoot

If you want the server to autostart on boot, run:

sudo nano /etc/rc.local

add the line:

`sudo python /home/pi/kilnController/kilncontrollerd.py &`

Client Access

Open Browser and goto http://127.0.0.1:8080 (for local development) or the IP of your PI and the port defined in config.py (default 8081).

Build Instructions

I put together some step by step instructions on https://www.instructables.com/id/Build-a-Web-Enabled-High-Temperature-Kiln-Controll

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

picoReflow

For more info on the parent project, see picoReflow: https://apollo.open-resource.org/mission:resources:picoreflow