UPDATE: I have taken photos and started editing them preparing the whole step by step guide, soon ( i'm thinking next week ) it should be all ready and published here.
Better documenting coming soon, just delayed a bit by some job/life things i need to sort out now
Gaggiuino started as an idea to improve an already cappable coffee machine while keeping the machine looks and buttons functionality as close as possible to the original, an important part is that no internal cables/connectors were modified, all the connections were made by creating splitters using the purchased spade connectors.
First and foremost please do not underestimate the danger of electricity or overestimate your ability to work around it, only start working on your machine while it's completely disconnected from the mains power socket, also by agreeing to follow the bellow guide i cannot be deemed responsible for any of the damage you induce to your house appliances, yourself, your cat, friend or gold fish and it will be entirely your fault!
I will assume you have the necessary components and installed the related software, for the sake of not gettign stuck at some point just double check again the list bellow.
<< PROJECT REQUIREMENTS >>
- Arduino IDE
Needed to upload the code ".ino" to the arduino ROM
- Nextion Editor
Only necessary if planning on editing the ".HMI" file to ammend the LCD functionality
- CH340 USB Driver
USB driver so your system recognizes the Arduino clone board, let's say i have found this the hard way as apparetly the majority of cloned arduinos use a cheaper USB controller comparing to "genuino"
- Arduino Nano - Be sure to buy the AT328 version, also if you're buying the mini usb version buy the cable from them, you'll save yourself a lot of problems.
- Nextion touch screen (i used a 2.4 inch one)
- MAX7765 thermocouple
- C-M4 screw K-Type thermocouple sensor
- 40DA SSR Relay
- Thermo-resistant cables AWG 15 ( 1m black/red ) and AWG 30 ( 1m black/red/yellow )
- Spade connectors M/F 6.3mm
- 5v power supply - for powering the arduino board once it's inside the machine.
I used an old mobile charger i had lying around which conveniently had a USB port for plugging the cable that came with the board.
- Heat shrink
- U-shaped Parallel Terminal - These are in case you're coosing not to solder
- Soldering iron - the one i bought for my soldering needs, seems to do a great job
- Nextion LCD case
- Magnet sheet
First you need to understand what goes where, the schematics isn't really rocket science but for someone who's never disasembled or has no experience working with electrical circuits it might get very confusing real fast so i will try to describe it as simple as possible, sometimes adding some photos as well. First you need to check your setup works as expected outside the machine so you don't ahve it all installed and realise just afterwards it's not reading any temperature because of a faulty thermocouple or any other element, or your relay doesn't go between the ON/OFF modes.
- The first step will be connecting the max6675 module to the arduino board using the pins defined in the code, you can find them defined at the top of the .ino file ( pins 4,5,6 )
- Connect the relay, for now only connect the circuit controlling ports to check whether the relay LED indicates the power states.
Relay 3 to Arduino GND, Relay 4 to Arduino D8, the ports 1 and 2 on the relay are the high voltage circuit breaker
- Plug the arduino board using the mini usb cable that came with it and upload the code to the arduino board.
Note: uploading won't work with the LCD connected
- Upload the .HMI file on a microSD card
Note: card needs to be FAT32 formatted
- Insert the card in the LCD card reader slot and connect the LCD to the arduino board.
Nextion TX goes to Arduino RX, and RX to TX, VCC goes to Arduino 5V and GND to GND
- After upload finished get the card out and power cycle the LCD.
- You should see temp readings on your screen if everything went according to the plan.
Don't forget to test the thermocouple/relay combo operation, apply some heat to the thermocouple end and see whether the relay led operates in HIGH/LOW modes