fx2lib/examples/i2c/i2c.c

   1 /**
   2  * Copyright (C) 2009 Ubixum, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  17  **/
  18
  19
  20
  21 #include <fx2regs.h>
  22
  23 #include <i2c.h>
  24
  25 #define LED_ADDR 0x21
  26 #define BTN_ADDR 0x20
  27
  28 #define KEY_F1 0
  29 #define KEY_F2 1
  30 #define KEY_F3 2
  31 #define KEY_F4 3
  32
  33
  34 BYTE digits[] = { 0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x98, 0x88, 0x83, 0xc6, 0xa1, 0x86, 0x8e  };
  35
  36
  37 /**
  38  * This is pretty much the same function that is provided as the dev_io example from Cypress
  39  * Except is uses i2c read and write functions not from their library
  40  **/
  41 void main(void) {
  42
  43     BYTE    num = 0;
  44     //BYTE xdata        buttons;
  45     BYTE    buttons;
  46         BYTE    kstates = 0xff;
  47         BYTE    kdeltas;
  48         BYTE    key;
  49         BYTE    display = 1;
  50
  51         while(1)
  52         {
  53                 i2c_read ( BTN_ADDR, 1, &buttons );
  54
  55                 kdeltas = kstates ^ buttons;                    //
  56                 kstates = buttons;
  57                 key = 0;
  58
  59                 while(kdeltas)
  60                 {
  61                         if(kdeltas & 0x01)
  62                         {
  63                                 if(!((kstates >> key) & 0x01))
  64                                         switch(key)
  65                                         {
  66                         case KEY_F1: // wakeup?
  67                                                         num = 0;
  68                                                         break;
  69                                                 case KEY_F2:
  70                                                         if(--num > 0x0f)
  71                                                                 num = 0x0f;
  72                                                         break;
  73                                                 case KEY_F3:
  74                                                         if(++num > 0x0f)
  75                                                                 num = 0;
  76                                                         break;
  77                                                 case KEY_F4:
  78                                                         num = 0x0f;
  79                                         }
  80                                 display = 1;
  81                         }
  82                         kdeltas = kdeltas >> 1;
  83                         ++key;
  84                 }
  85                 if(display)
  86                 {
  87             i2c_write ( LED_ADDR, 1, &digits[num], 0, NULL );
  88                         display = 0;
  89                 }
  90     }
  91
  92 }