Smart - Coffee: Arduino Mega version

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