espresso shot timer

features

• 7-Seg style graphic output on I2C-OLED display
• temperature display
• control of baristlight during shot (digital or PWM)

by Dario Carluccio (user dondario of http://www.kaffee-netz.de) <shottimer.at.carluccio.de>

based on idea and hardware from

• David Kißling (user mactree of http://www.kaffee-netz.de )

todo

• change switch input to valve and measure preinfusion seperate
• design new display output if inactive
• store values in eeprom
  • no. of shots longer than MIN_SHOT_TIME - UNSIGNED LONG
  • seconds of pump operation - UNSIGNED LONG
• add barista light control

changelog

• v2.1 rev 002 - baristalight added with many configuration options (pin configuration, polatity high/low active, pwm speed on/off, timeout)
• v2.1 rev 001 - Complete code rewritten, baristalight still missing

connections

• OLED display
  • GND connected to GND
  • SDA connected to SDA
  • SCL connected to SCL
  • VCC connected to 5V
• switch input
  • D5 LOW ACTIVE
• pump input
  • D6 LOW ACTIVE
• DS1820 temperature sensor (optional)
  • GND connected to GND
  • Data connected to Port 2 and to a 4k7 resistor
  • VCC connected to 5V and to the other pin of the 4k7 resistor
• Barista Light via relais - ON-OFF only (optional)
  • 13 polarity configurable
• Barista Light via MOSFET - dimmable (optional)
  • 10 polarity configurable

libraries needed

• Bounce2, Version 2.21
• DallasTemperature, Version 3.7.7
• MicroLCD
• OneWire
• Wire - part of Arduino installation