i want to create a small automated greenhouse as a school project.
i already figured out what kind of sensors and tools i want to add but i am not sure how to approach next;
it should have a humidity / temperature sensor, water level sensor , PH measurement, programmable LEDS, LCD display 3.5 inch,ventilation .
i want to add a 4 relays arduino shield so i can add 4 switched in between, but i am not sure what type of arduino i need and what kind of supply.
should i go for the Arduino Mega or is it overkill and will the Uno be sufficient?
what kind of supply should i use? i Was thinking about an ATX PSU from a PC but i am not sure it is a good idea.
if you have any tips feel free to share! Thanks in advance
An Uno would probably do just fine, depending on how many pins you need for your displays.
Start with getting each individual part working, then integrate adding one component at a time.
Power supply: grab an old 5V mobile phone charger. 1-2A will probably do, depending on how many LEDs you want to add, and what you want for ventilation (you may want to use a 12V fan, on separate power supply).
I agree with wvmarle - start with the Uno and solve your questions 1 at a time as you come to them. You will learn many things by simply starting and learning what works for you. You may find your requirements change as you build on the complexity of your project.
Seems like we get at least two greenhouse projects a week in the forum - look back or search the forum and see what others have done - but make sure you understand the engineering and design as well as put your own ideas into your project since this is a school project you want to really learn the whole project - as well as the way you get to finish - I still remember parts of my first full controls system design some 25 years later and parts of the learning curve and things I had to go back again on