SACI Temperature Controller

SACI (Seu Amigo Cervejeiro Inteligente, or Your Smart Brew Buddy in a quick translation) is a NODEMCU 1.0 (ESP8266 12-E) temperature controller for homebrewing and beer fermentation.

SACI was built using inexpensive parts available in any electronic store (see the BoM and schematics below) and its software was written in C/C++ using Arduino/Genuino framework. So SACI is easy to build and easier to hack.

Reliable behavior with new brains

If you are a homebrewer, the chances are you already know of and rely on ON/OFF controllers (STC-1000 is a world wide example) to ferment your beer. SACI uses the same logic for temperature control and offers new possibilities, like data logging with IoT free services (e.g. MatLab thingspeak.com), automatic profile, responsive web interface and the chance to write your own plugin or interface.

Automatic profile

SACI was built with a set and forget mindset. You plug it in your fridge, adjust target temperature, create a profile for the next two weeks and done. You can do other tasks, and SACI will evaluate time using NTP and adjust your target temperature based on your profile.

Clean and Responsive Web Interface

We don't like bloated interfaces, so we choose to keep it clean and 100% browser ready. SACI has an responsive interface, beautiful in any device. Nothing to install, just point your PC or smartphone to SACI IP address and configure it.

Over-the-air updates

Is your SACI laying behind your fridge and you are not in the mood to push it just for a small update? No problem. SACI has Over-The-Air enabled at boot, so you can code and update directly from your notebook or desktop.

Arduino/Genuino IDE Compatible

You already use Arduino/Genuino Framework to write your own code and want to write your own plugin using it? No problem. The code is compatible with Arduino/ESP8266 language and IDE. No additional software required.

Easy to build and hack

Anyone armed with soldering wire and a dozen of components can build and modify SACI hardware, and because of Arduino/Genuino framework, everyone can write plugins in a couple of hours. In fact, SACI already has plugins for MatLab Thingspeak services, influxDB time series database and a draft for Rsyslog integration (some work is needed here).

HTTP POST config and json responses

All the configuration is passed to SACI over URL encoded post, so, if you know how to manipulate this, you are able to create your own interface and/or dashboard to view your brew status.

Everyone loves MQTT

Just push information to your smartphone or desktop using one of bazillions free MQTT dashboards and public brokers around the internet.

Plugin Ready

Already have a working code for this and want to put it in SACI?

Just get your code and put it inside the plugins directory and insert your function inside main loop and your plugin is ready to work. SACI was sectioned to enclose things that need be enclosed together, creating an easy to maintain and less fragmented code.

Built with ESP8266

The chip behind SACI is the well-beloved ESP8266 (12E). A NodeMCU in a protoboard or a full production-ready PCB layout with fancy SMD components. WeeMos or generic devkit boards, does not matter. It's ESP8266 after all.

Hardware Build Instructions

Schematics

Shame on me here! I don't have the skills to write electronic diagrams and schematics for other people, and don't have time or will to overcome this. To be honest, I barely can read my own schematics. If you decide to build your own PCB, you will find the etchable layout, a totally messed up Fritzing file and this JPG file to help you with wiring. Any help to improve this will be over-happily welcomed.

PS: Works on 127v or 220v

Bill Of Materials

• 1x nodeMCU 1.0 or ESP8266-12E chip/board

• 2x 15 pin female header (single row)

• 2x BC546 NPN Transistors or equivalent

• 2x 1n4148 Zener Diode or equivalent

• 2x 5V coil relay (10A) or SSR

• 2x 2 pin screw terminals

• 1x 3 pin screw terminal

• 1x 4.7K resistor (1/4W)

• 1x DS18B20 temperature sensor

• (OPTIONAL) Another DS18B20 for fridge temperature

• 2x power sockets for fridge and heat element

• 1x plastic case of your preference (or none)

• Materials for soldering, PCB build and wires

Software Build Instructions

Dependencies

• OneWire

• DallasTemperature

• NtpClient

• PubSubClient

PlatformIO

• Clone this repository

• On PlatformIO menu, click on "Open Project Folder" and select repository folder

• On PlatformIO menu, click on "Initialize or Update PlatformIO Project"

• Choose NodeMCU 1.0 and click process

• Update your platformio.ini file as bellow

[env:nodemcuv2]
platform = espressif8266
framework = arduino
board = nodemcuv2
build_flags = -Wl,-Tesp8266.flash.4m1m.ld
board_f_cpu = 160000000L
#Change if you are on windows, Mac or using OTA
upload_port = /dev/ttyUSB0 #Linux
lib_deps =
  OneWire
  DallasTemperature
  NTPClient
  PubSubClient

• Create your 'src/config.h' file (use 'src/config.sample.h' as example)

• Enable/Disable desired plugins on config.h

• Build main image and upload

• Build SPIFFS filesystem and upload.

• Find your address using serial monitor

• Access and configure

Arduino IDE

• Install ESP8266 support as described here

• Install the dependencies using Arduino Library Manager or download and by yourself

• Rename 'saci-temperature-controller/src/main.cpp' to 'src.ino'

• Copy all h and cpp files from plugins folder to src folder

• Open src.ino file

• Create and edit config.h file (use config.sample.h as example)

• Fix path errors on CPP/H files in plugins directory

• Select NodeMCU 1.0 as board

• Select 160Mhz CPU Frequency

• Select Flash Size 4M (3M SPIFFS)

• Select Upload speed 115200

• Build the software

• Deploy firmware and filesystem using OTA or USB port

CLI

You can build SACI in any operating system with support to Python 2.7 and PlatformIo-Core. The instructions below are tested headless Raspberry PI with latest Raspbian distro.

Check the docs if the method below does not work for you.

$ sudo apt-get install python-pip
  #Fix errors about requests
$ rm -rf /usr/local/lib/python2.7/dist-packages/requests*
$ sudo -i pip install -U platformio
$ git clone https://github.com/jalexandre0/saci-temperature-controller.git
$ cd saci-temperature-controller
$ cp src/config.sample.h /src/config.h
$ vim src/config.h
$ platformio run -t upload
$ platformio run -t uploadfs 

Help and to-do:

• Test any CLI build mode

• Improve software build instructions

• Write electronic diagrams that people can read and follow

• Review hardware and schematics to improve safety

• Fix typos and spelling errors

• Save and load profiles by name

• Fix / Clean up / review code

• Test and write instructions for Farenheit temperature

• Test or port the code for Atmel hardware (Arduino/Genuino based boards)

• Run other algorithms outside the hardware (slave mode)

• Improve HTTP API

• Add continuous integration

• Add unit tests