The Calculator have default game function (1.jpg) where are left/right numbers (0…100) selected by rotary encoders. It show two lines with adding and multiplying.
There are four Examining functions which are selected by right black pushbutton.
- just adding
- just multiplying
- just subtracting (as complement to adding)
- just dividing (as complement to multiplying)
- back to default game function (with short beep)
Left black pushbutton button is HELP function which show both rows of the results (adding, multiplying). HELP function will do a long BEEP.
If battery is low, then it write message CHARGE ME and beep. Power consumption is less than 15mA (with Arduino Pro Mini 3.3V/16MHz, does not have 8MHz version now).
- LCD VCC and Arduino RAW to switch, other wire from switch to B+
- B+/B- to charger board
- Vcc from arduino is directly via pin header connected to LCD A (LED backlight)
- Encoder Left: D7,D8,D9
- Encoder Right: D10,D11,D12
- Note that middle pins are connected for data pins too (not needed, but I was do it for less wire mesh)
- LCD pins RS E D4 D5 D6 D7
- To Arduino Pins: A4, A5, A0, A1, A2, A3
- Other LCD pins:
- 5k…20K potentiometer - ends to +5V and ground, wiper to LCD VO pin (pin 3)
- LCD R/W pin to ground
- LCD Vss to GND
- LCD Vdd to Arduino RAW
Pushbutton 1 to 4 and other end to GND
Pushbutton 2 to 6 and other end to GND
Beeper to pin 5 and GND (resistor is better but not explicitly needed due short PWM pulses). But better is connect other pole to Vcc and modify PWM values accordingly (2=>253, 3=>252). But I have more GND points than Vcc.
1x Arduino Pro Mini
1x LCD 1602
1x On-Off switch 7x7mm
2x pushbutton 6x6x8mm
2x rotary encoders
1x Li-Ion MINI USB charger
1x old Li-Ion battery from mobile phone
Dupont jumper wires, wires
female pin header 5 pins (1602: D4…D7, K)
male pin headers
switch box on top of wall
LiquidCrystal (from Arduino IDE)
Quadrature (modified - you need to change Wconstatns.h to Arduino.h elsewhere)
The unmodified Quadrature Arduino library is here:
Quadrature_OK.zip (9.1 KB)
Kalkulator_LCD_2xRotaryEncoder_rc02.txt (6.34 KB)