Hi
I am looking for some advice on how to best go about my project. I am a product designer so my knowledge of electronics is basic.
I am trying to make a coffee machine with an Arduino but I want it to have controllable features.
*Temperature output
*Volume
*Timing
It will also have one - three cycle so would need to be able to set each controllable feature on each cycle.
I was thinking of having a control knob for each controllable feature with its own Digit 7-Segment Display (Adafruit 0.56 4-Digit 7-Segment Display w/ I2C Backpack - Blue [STEMMA QT / qwiic] : ID 881 : $11.95 : Adafruit Industries, Unique & fun DIY electronics and kits) for the user to set volume temperature and timing.
How would I control the heater? I am thinking of using some through flow heater to get almost instant hot water.
Will I have issues running the Ardunio with a higher voltage heater? will I need to use relays?
I very much appreciate any help anyone can give me as I am at the start of the project and am not sure where to start?
Thanks again
temperature, read and control = arduino
volume, probably either a level or timeing thing = arduino
timing = arduino
yup, all works. probably relays for the heater
solenoid for the level
You'll need something to measure the temperature. The LM34/LM35 are easy to use, but check to make sure they can go high enough. And/or you can use a thermistor.
If you want time-of-day programming you'll need a Real Time Clock module (RTC). You can do time-of-day with just the Arduino, but the clock time will drift more than an RTC and you'll have to reset it if power goes out. (The RTC module usually has it's own back-up battery.)
The solenoid valve will need a driver circuit (a transistor or MOSFET). You can't power it directly from the Arduino.
Solenid valves and flow-measurement sensors tend to be expensive. An alternative to flow-measurement would be to measure the weight of the pot and the coffee... That's doable but it's not super-easy.
I am thinking of using some through flow heater to get almost instant hot water.
I have a "feeling" that a regular coffee pot is already heating the water as fast as possible with the ~1500 Watts available from a regular electrical outlet. It doesn't take any more total energy to heat it faster, but it takes more power over a shorter period of time.
I believe those "instant hot water" taps on a kitchen sink have a small pre-heated tank. A tankless water heater usually runs off a generous source of natural gas. Again, over the short term it burns more gas than a regular water heater, although over a full day the regular water heater consumes more gas while keeping the water hot all of the time.