Add dc calibraion

• Small patch adds ability to calibrate input voltage measurement in the Extras menu (Press B button when showing voltage, then press buttons up and down until reads closest to input)

Improved Temp accuracy + New idle screen

• Increase the accuracy of the temperature profile
• Allows temp offset calibration on the misc menu (Press A+B at idle), followed by B
• Much nicer screen on idle with prompts for both buttons (Using Miniware drawing of the iron)

Improved Button Handling + Adjust sensitivity

+Improved button handling
+Set sensitivity of motion (Need feedback if this needs adjustment)
+DC voltage can be read by going to thermometer page (press both buttons in IDLE), then press either button to swap to DC Input.

V1.02 - Thermometer mode & Double button exit & Screen fix

This update adds a thermometer mode, which shows the measured temperature at the tip of the iron.
It also changes the soldering mode exit from the B button, to holding both buttons together (Like original firmware).

This also fixes the screen in left-handed mode (flipped display). This should clear the issue with the line of crap on the screen.

V1.01 - Left Handed and Fahrenheit

Added options to flip the screen for Left Handed users.
Added option to display in Fahrenheit instead of Celsius.
Shrunk text spacing slightly to allow for better text in menus.

Version 1.0 First complete release

Added most of the missing features.
Tested on two units.

Pre-Alpha release

Drag and drop upgrade using the built-in USB bootloader.
Hold the button closest to the tip and plug in usb, you should see "DFU" on the screen.
Drag the .hex file onto the usb drive that shows up in your computer.

Soldering works, but missing features :

• Under voltage cutout
• Settings Saving