Hello everyone! This project is for anyone who owns a Lelit Mara X (V2) espresso machine. When looking for a new espresso machine, one feature I always wanted was a shot timer. Usually the machines are beautifully designed so I didn't want to ruin the look by adding a $5 kitchen timer to the machine. So far so good. Now you are going to say : Dude the MaraX doesnt have a Shot-Timer?! Yes, you are right but the MaraX has a serial interface! As a developer and tinkerer a ready to use serial interface is more interessting then a ready to use Shot-Timer ;)
- Arduino Nano (You can use any other equivalent board)
- Breadboard
- Jumper-Wires
- 0,96" SSD1306 OLED Display
The MaraX has a 6-PIN Connector for the serial interface on the bottom. We only use PIN-3 (Mara RX - Black Wire - Green Rectangle) and PIN-4 (Mara TX - Orange Wire - White Rectangle). For testing you can use the jumper-wires later you should replace them with temperature protected cables.
- PIN3 Mara to D6
- PIN4 Mara to D5
RX Mara to TX Arudino TX Mara to RX Arduino You will receive the following data each ~400ms.
The serial interface itself
Note: I also did some tests with a reed sensor and the vibration pump. However its not necessary for the MaraX the interface provides the information about the status of the pump. Maybe I will do another project for a Shot-Timer only for espresso machines with a vibration pump only :-)
Example Data: C1.06,116,124,093,0840,1,0\n
- The delimitter is: ,
- The end of data is: \n
- Length: 26
| Data | Description |
|---|---|
| C | Machine-Mode: C = CoffeeMode; V = Vapour/SteamMode |
| 1.06 | Firmware |
| 116 | Current Steam Temperature in Celsius |
| 124 | Target Steam Temperature in Celsius |
| 093 | Curent Hx Temperature in Celsius |
| 0840 | Countdown Boost-Mode |
| 1 | Heat state (0 = off; 1= on) |
| 0 | Pump state (0 = off; 1= on) |
| Pin Display | Pin Arduino Nano |
|---|---|
| VIN | 3,3V or 5V |
| GND | GND |
| SCL | A5 |
| SDA | A4 |
The reset pin is 0x3D or 0x3C. You can recognize it by the solder joint on the back side
- Wire.h
- Adafruit_GFX.h
- Adafruit_SSD1306.h
- SoftwareSerial.h