Hotend, fan, weight & scale control w arduino uno

The user should be able to control the process easily and edit the temperature for the hotend easily. The user edits the program to the temperature he wants. The hotend heats up --> The Hotend melts the compound -->the compound-fluid drops on the scale. Code/ wiring for Arduino Uno (Windows): - Control a Hotend (Thermal Resistor Vishay Power Resistor 6,8 Ohm/3 Watt Thermistor: Honeywell, 100k, Toleranz: 5% ) - read weight from a load cell ( over sparkfun HX711 amplifier) - Control fans for cooling (just on/ off, 2 * 12V DC ) - time the time from starting the program to the end of the program - write data ( Temperature, time, weight) over usb to windows - no LCD - start program over windows (?)