Espressuino – DIY PID, Bluetooth and Preheat Coil on Gaggia Classic

Last updated: Thursday, October 24, 2019

 

>>> Here is the Poemia version <<<

This is a multifunctional Homemade PID controller (more info here), based on Arduino, connected to my Gaggia Classic espresso machine. If you are interested in a Raspberry PI project, take a look at here.

Added LCD and Bluetooth support and some modifications to the software of BBCC (BareBones Coffee Controller) project by Tim Hirzel and to the TC4 Android App by Brad ( Thank you! )

Espressuino on Gaggia Classic Test 1:

Flush, Preinfusion and Power Save Mode test:

1) Temperature stability under Double Shot extraction:

2) Temperature stability under Double Shot extraction:

Automatic Descale Function:

Two different User / Grinder Timer settings:

Volumetric Learn Mode:

AutoBackflush Mode:

Gaggia Classic shot:

Test Software v3.0:

Bluetooth Demo using Galaxy S2:

Mazzer Major Retention:

Functions:

  • Bluetooth Support (HC-06 module, v3.1)
  • Manual or Automatic mode
        •  Manual:  Start (Stop) the pump manually for max. 99 seconds or Volume in ml (+ Preinfusion)
        •  Automatic: The pump will start automatically when the temperature reach the set value (Duration in Seconds or (Volume) = Preinfusion + (Shot value) )
  • Time or Volumetric Mode (TIM / VOL, v3.0)
  • Espresso and Steam temperature settings
        •      Espresso temperature:  min. 60°C  –  max. 110°C
        •      Steam temperature:      min. 100°C  –  max. 155°C
  • Grinder Timer function (1 > 40 seconds, using SSR,  v1.6)
  • AutoFlush function (v1.8)
  • Power Save Mode (default 30 minutes, v1.8)
  • Automatic Descale Function (default 1 cycle with 15 minutes delay, v1.9)
  • Set 2 different User preferences
  • Set 2 different Grinder Timer parameters (0.1 sec interval, v2.0, Grinder T2 available only when AutoFlush is deactivated, same button used)
  • Automatic Software Pressure Control:    min. 8.0bar – max. 15bar (v1.5)
  • AutoFill -up function for the boiler, while steaming (for longer steam possibility – v1.5)
  • 3 Way Electrovalve control (v1.7)
  • PID controll for heater (real time P – I – D tuning, using BBCC Plotter)
  • Pump controll
  • Improved Pressure measurement ( 0 > 15bar, using pressure transducer 0.5V > 4.5V, v1.8 )
  • Improved Preinfusion function (duration settings  0 > 20 cycle, delay must be included)
  • 2 buttons (shared) for different Shot duration settings ( Time Mode, 1 > 60 seconds, v3.0 )
  • 2 buttons (shared) for different Volume settings ( in Volumetric Mode, 5 > 250ml, v3.0)
  • Learn Mode (Volume) for 2 (shared) different buttons (v3.0)
  • AutoBackflush Mode (for cleaning GroupHead and 3 way valve, v3.0)
  • display different Volume Units (number of pulses from volumetric sensor or ml, v3.0)
  • display Shot duration in Volumetric Mode (seconds, v3.0)
  • Espresso counter (any extraction longer than 15 seconds, will increment this counter v3.0)
  • Delay for Preheat Group Head ( 0 > 99 minutes – v1.2 )
  • Buzzer (Sound ON / OFF from menu – v1.1 to v1.4)
  • Backlight Control (not implemented in software, removed from v3.0 due to HW changes)

Protections:   

  • short or unconnected thermistor pins ( “Terr” message on the display, push buttons and SSRs  are blocked until problem solved and system restarted).
  • in Manual and Volumetric Mode, after 99 seconds the pump will turn Off automatically.
  • Power Save Mode, will Turn Off the Heater after a preset period (default 30 minutes)

Documentation for connecting to Gaggia Classic :

For SW v3.0 and HW v1.2 (or above):

For older SW and HW:

Circuit Diagram :

Arduino and Android (for v3.1) Source Code :

P4 Connector pinout:

  1. Power Supply Input  (+7V to +12V)
  2. GND ( – Common Ground, connected to DB9 Shield)
  3. Vcc OUT (+5V Common)
  4. SSR Heater (to SSR LED – input)
  5. Vcc OUT (+5V NC for DB9 connector)
  6. SSR Pump (to SSR LED – input)
  7. Vcc OUT (+5V NC for DB9)
  8. Temp. sensor input (to thermistor)
  9. Vcc OUT (+5V NC for DB9)
  10. Pressure transducer input (to pressure transducer output (0.5V to 4.5V))

P2 Connector pinout:

  1. GND (NC for DB9)
  2. AREF (NC for DB9)
  3. ADC6 (NC for DB9)
  4. Volumetric Sensor (to pulse output)
  5. SSR Grinder (to SSR LED + input)
  6. SSR EValve (to SSR LED + input)
  7. RX (HC-06 Bluetooth TX)
  8. TX (HC-06 Bluetooth RX)

Push Button functions in firmware v3.0 or higher :

  • S1 – ” SET // AV2/AT2 ” – enter Settings Mode and Set Value // AutoVolume2/Time2 Mode
  • S2 – ” ST / SP / – // AV1/AT1″ – Start / Stop / Decrement // AutoVolume1/Time1 Mode
  • S3 – ” TIM / VOL / + // GRD2\AFL” – Time/Volume/Incr. // Grinder2 or AutoFlush Mode
  • S4 – ” STM / ESP // GRD1″ – Steam / Espresso // Grinder1 Mode

// – available when longpress

Other functions available at startup (keep pressed then turn ON the espresso machine):

  • S1 – “Bckf” – Start AutoBackflush Mode
  • S2 – “Dscl” – Start Automatic Descale Mode
  • S3 – “User2” – Load User 2 preferences
  • S4 – “User1” – Load User 1 preferences
  • S1 AND S2 – “Learn” – Start Volume Learn Mode
  • S3 AND S4 – “Reset” – Reset Espresso Counter to 0

Push Buttons functions in firmware below < v3.0 :

  • S1 – ” SET ” – enter Settings Mode and Set Value
  • S2 – ” ST / SP / – ” – Start (Pump) / Stop (Pump) / Decrement
  • S3 – ” A / M / + ” – Auto (Mode) / Manual (Mode) / Increment
  • S4 – ” STM / ESP ” – Steam (Mode) / Espresso (Mode)

Other Softwares and drivers needed for this project:

  Build and / or use at your own risk !!!

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