PLEASE NOTE:
The latest version of Smart-Coffee can be found here: https://www.schematix.co.nz/forum/how-to-s/smart-coffee-pcb-v1-4
Smart - Coffee: Arduino Mega Version is highly customizable software that runs on an Arduino or similar microcontroller, to control the various functions of an espresso machine.
The software can be configured to replace the factory controller functions such as:
Control the boiler pressure using programable PID or PWM logic
Check the boiler water level through the factory-fitted probe
Refill the boiler by activating the pump and refill valve
If a water reservoir tank is present, it can check the water level using a probe OR via a switch. If the reservoir is empty, the element and pump will be disabled until the reservoir is refilled
In addition, the software can add extra features such as
OLED display that can show pressure, temperature, water tank level, mode, pump & element icons, and more in both metric or imperial units
Pre-infusion cycle what can be customized to pre-infuse the coffee grounds at low pressure before extracting the shot (activated when Espresso mode is ON)
Espresso Mode which can be customized to stop the pump after a programable amount of water is dispensed.
Flow meter which can keep track of how much water has been dispensed
Espresso timer which automatically stops the pump after a programmed amount of time
Water reservoir level can be measured using an ultrasonic sensor and printed on the display. No more manually checking to see if you need to refill the reservoir tank!
Pause a boiler refill from happening when an espresso shot is being made
Temp sensor which can be used to measure any temperature on the machine
Safe mode which can be programmed to shut down in the event the pressure and/or temperature exceed the programmed limits
Buy smart coffee here
Download a preview version of Smart Coffee software here
(The preview version allows you to view the Setup and Guide pages before purchasing)
Watch the video to learn more about smart coffee here
Video Playlist for configuring Smart Coffee here
Espresso Machine Compatibility:
Smart Coffee should be compatible with most single boiler (aka heat exchange) machines that have the following hardware:
Water Pump
Solenoid valve (to refill boiler)
Heating element
Boiler water level probe
Brewing switch
If your espresso machine uses a currently unsupported hardware configuration, you can submit a request below to have your hardware configuration supported with a future update.
UPDATES to Smart Coffee:
V2.0
First Released Version
V2.1
Added the option to use temperature as the target for the boiler element control.
Added the option to disable pressure safety limits.
Added the option to disable the pressure transducer.
Renamed "TEMPERATURE_SAFETY_FEATURE_ENABLE" to "TEMPERATURE_SAFETY_LIMITS_ENABLE"
v2.2
Refined and optimized logic
Updated pressure reading units to display 0.0 resolution
Changed printed display value "Kpa" to "kPa"
Added multiple attempts to connect to max31865 temp sensor
Updated serial printing logic
Removed obsolete serial printing commands inside the brewing logic
DOWNLOADS:
Download STL files to print the SH1107 display mount here
Download the wiring diagram here
Download a preview version of Smart Coffee software here
(The preview version allows you to view the Setup and Guide pages before purchasing)
WIRING DIAGRAM:
Adafruit MAX31865 board configuration: https://learn.adafruit.com/adafruit-max31865-rtd-pt100-amplifier/rtd-wiring-config
FAQs:
Will there be updates for Smart Coffee? Yes, we’re brainstorming several ideas and features to add to smart coffee.
My machine has a different hardware configuration, will Smart Coffee support it in the future? One of our goals is to have Smart Coffee be highly compatible with most espresso machines. If your espresso machine uses an unsupported hardware configuration, you can submit a request to have your hardware configuration supported with a future update.
Do you offer technical support? No, we do not offer individuals technical support for installing Smart Coffee. Our videos, guides, information, and software are supplied for educational purposes only.
Are there any warranties given or implied? No. Smart Coffee software is supplied for educational purposes only.
Are future updates free to download if I purchase Smart Coffee? Yes, once you buy Smart Coffee software, future updates will be free to download. As the project evolves over time, there may be variants of Smart Coffee, for example, ‘Smart Coffee – Dual Boiler edition’ which may require a separate purchase.
Hardware list:
(affiliated links, thanks for your support)
Pressure transducer: https://s.click.aliexpress.com/e/_DD26P6x
Input: 5V
Sensor output: 0.5 ~ 4.5V
Pressure range: 0 ~ 0.4Mpa (400Kpa)
Thread: G1/4 (aka ¼” BSPP)
(thread adapter may be required to fit different machines)
¼” BSP to G1/4 adapter: https://s.click.aliexpress.com/e/_DmjM9T5
Right angle adapter: https://s.click.aliexpress.com/e/_DCGZhH5
Arduino MEGA 2560 PRO: https://s.click.aliexpress.com/e/_DEqZP9t
OLED display: https://s.click.aliexpress.com/e/_DlNwzh1
OLED SH1107 display
Interface: I2C
Pixels: 128x128
Input: 5V
Ultrasonic Ranging Sensor: https://s.click.aliexpress.com/e/_DdEwlEb
Model: A02YY
Output signal: PWM
Input: 5V
(Solid state relays with appropriate current and voltage ratings for the pump, refill valve, and element)
2 Channel SSR: https://s.click.aliexpress.com/e/_DEuadS3
Control: 5V Low-level logic (aka GND pin to turn relay ON)
Load current: 2A
Load voltage: 250VAC
40A Solid state relay: https://s.click.aliexpress.com/e/_DkRF9Ij
Control: 3 ~ 32VDC
Load current: 40A
Load voltage: 24~480VAC
MAX31865 temp sensor with probe: https://s.click.aliexpress.com/e/_DefQQLp
Adafruit MAX31865 board configuration: https://learn.adafruit.com/adafruit-max31865-rtd-pt100-amplifier/rtd-wiring-config
Small size flow meter: https://s.click.aliexpress.com/e/_DFDQ3vv
Model: USN-HS06P
5 ~ 12V
6mm OD
30 ~ 150ml/min
Medium size flow meter: https://s.click.aliexpress.com/e/_Dl8u7QT
Model: USN-HS06PS
5V
6mm OD
0.1 ~ 1.5L/min
(For a high-pressure flow meter, google search for “GICAR flowmeter” or similar)
Chrome on/off Switch: https://s.click.aliexpress.com/e/_DdqG6h9
Micro USB panel mount: https://s.click.aliexpress.com/e/_DBQWf5h
5V PSU: https://s.click.aliexpress.com/e/_DBJgyX1
Model: MeanWell - RS-15-5
Output: 5VDC, 3A
Miscellaneous:
2mm Clear acrylic sheet (for OLED display mount): https://s.click.aliexpress.com/e/_DDmUUlh
(Display mount acrylic screen size: 2x38x50mm)
Connectors: https://s.click.aliexpress.com/e/_DdGNokf
(I used 2x 4pin connectors in my build, however this assorted pack comes in handy)
Plastic enclosure: https://s.click.aliexpress.com/e/_DD9Nslv
(Purchase an enclose that has sufficient space for the electronics you're using and fits inside your machine)
Shielded multi-core cable: https://s.click.aliexpress.com/e/_DmRkGGd
(26AWG, 10core shielded cable)
Dupont crimping tool: https://s.click.aliexpress.com/e/_DkR40YX
Rivet nut tool: https://s.click.aliexpress.com/e/_DE05vaf
Is it possible to use the arduino version without the display and pressure transducer? I'm looking for a solution to replace a Gicar box with heating element safety feature.