Dual magnetic stir controller

Overview

This is the Arduino sketch to build a double magnetic stirrer based on 2 fans, a 1602 LCD display, a KY-040 encoder and an Arduino (e.g. Uno, Leonardo, Pro Micro).

In order to put the stirrer into operation you have to change the settings in stir.ino according to your setup.

Overview of Functions

All functions are controlled by the KY-040 encoder:

• Press briefly: change between menu, stirrer 1 and stirrer 2
• Turn when menu is selected: change between menu items (SPEED, BOOST, BTIME, CATCH, CTIME)
• Long press when menu is selected: Lock all functions (unlock also by long press)
• When a stirrer is selected:
  • SPEED: turn sets speed, long press switches stirrer on or off.
  • BOOST: turn sets boost speed, long press activates/deactivates the boost function (running time is shown in the display).
  • BTIME: turn sets the boost time in minutes.
  • CATCH: turn activates/deactivates the fishing function
  • CTIME: turn sets the interval in minutes for the fish catching function

Display Indicators:

• Bottom Left: Menu
• Bottom centre/right: Displays the set values for the stirrers depending on the selected menu item.
• Top Center/Right: Displays the current stirrer speed (or 'OFF' or 'CAT' (Fishing)).
• Top left: shows the remaining time of the boost function.

Settings (in stir.ino)

Value	Description
SPEEDINC	increment of speed values when turning the encoder
FANMIN	fan minimum speed (should be a value at which the fan runs safely)
FANMAX	maximum speed of the fan (it is important that this is the real maximum value of the fan)
RINTERVAL	regulation interval (ms)
RDELAY	extra regulation delay when value changes (ms)
RTOL	regulation tolerance
CATCHSTOP	stop interval for stir fish catch function (ms)
PWM0, PWN1	PWM output pins
I0, I1	interrupts for rpm measurement (2 and 3 for Leonardo and ProMicro / 0 and 1 for Uno)
CLK, DT, SW	pins for KY-040 encoder

Schematics