Library for (Robotdyn) 4x4 and 4x3 analog keypad.
AnalogKeypad is a simple library to read the keys from a (Robotdyn) 4x4 or 4x3 keypad. No other keypads are tested, but they should work with this library after adjusting the MAGIC NUMBERS in the function rawRead().
#include "AnalogKeypad.h"- AnalogKeypad(const uint8_t analogPin, const uint8_t bitsADC = 10) constructor, analogPin is typical A0 etc. BitsADC has a default of 10, but need to be set to match the platform. If bits < 8 then the internal shift would be too large causing all reads to return 0 or so.
- uint8_t pressed() returns 0 if no key pressed, otherwise returns key pressed (may fluctuate).
- uint8_t read() read the key pressed returns 0 .. 16 where 0 means NOKEY.
- uint8_t event() checks if a change has occurred since last time.
- uint8_t key() returns the key involved with last event.
uint8_t e = AKP.event();
switch (e)
{
case PRESSED:
Serial.print("press\t");
Serial.println(AKP.key());
break;
case RELEASED:
Serial.print("release\t");
Serial.println(AKP.key());
break;
case REPEATED:
Serial.print("repeat\t");
Serial.println(AKP.key());
break;
case CHANGED:
Serial.print("change\t");
Serial.println(AKP.key());
break;
default: // NOKEY
break;
}| Event | value |
|---|---|
| PRESSED | 0x80 |
| RELEASED | 0x40 |
| REPEATED | 0x20 |
| CHANGED | 0x10 |
| NOKEY | 0x00 |
The simplest usage is to use the read() function. This will return a 0 (NOKEY) when no key is pressed and a number 1 to 16 for the keys pressed. Note the return value may fluctuate randomly when multiple keys are pressed.
The pressed() function is a bit more robust. It returns the key pressed first, so multiple key presses simultaneously are less likely to disturb your program.
See Examples
- more examples
- self-learning example?
- make internal mapping array runtime adaptable?
- store in RAM, accessor functions
- version for external ADC
- see ADC712
- derive class for 4x3, 4x2 and 4x1 analog keypads?
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