1  // SPDX-FileCopyrightText: 2019 Anne Barela for Adafruit Industries
 2  //
 3  // SPDX-License-Identifier: MIT
 4  
 5  #include "Arduino.h"
 6  
 7  #define DISP_REGISTER 0x00
 8  #define KEYS_REGISTER 0x40
 9  #define MAX_BRIGHTNESS 12
10  #define MIN_BRIGHTNESS 0
11  #define INITIAL_BRIGHTNESS 1
12  
13  class HT16K33 {
14    private:
15      uint8_t i2c_addr;
16      uint8_t brightness;
17      uint8_t buffer[16];
18      
19      // all four variables are updated in readButtons()
20      uint8_t previousButtonState;  // stored in MSB First format: B7, ... , B0
21      uint8_t currentButtonState;   // stored in MSB First format: B7, ... , B0
22      uint8_t buttonFirstPress;     // stored in MSB First format: B7, ... , B0
23      uint16_t buttonHoldTime[8];    // stored in LSB First format: B0, ... , B7
24      
25      uint16_t* transposeMatrix(uint8_t* matrix);
26      void sendCommand(uint8_t c);
27      void setBrightness(uint8_t b);
28      
29    public:
30      HT16K33(uint8_t _addr);
31      void init();
32      void increaseBrightness();
33      void decreaseBrightness();
34      
35      void storeToBuffer(uint8_t* matrix);
36      void refreshDisplay();
37      void clearDisplay();
38      void readButtons();  // only reads the first byte of the key scan register becasue only the first 7 keys are used on this device
39      bool getButtonFirstPress(uint8_t i);
40      uint16_t getButtonHoldTime(uint8_t i);
41      bool allowToMove(uint8_t i, uint16_t time, uint8_t rate);
42  };