Adafruit_LEDBackpack.cpp

00001 /*************************************************** 
00002   This is a library for our I2C LED Backpacks
00003 
00004   Designed specifically to work with the Adafruit LED Matrix backpacks 
00005   ----> http://www.adafruit.com/products/
00006   ----> http://www.adafruit.com/products/
00007 
00008   These displays use I2C to communicate, 2 pins are required to 
00009   interface. There are multiple selectable I2C addresses. For backpacks
00010   with 2 Address Select pins: 0x70, 0x71, 0x72 or 0x73. For backpacks
00011   with 3 Address Select pins: 0x70 thru 0x77
00012 
00013   Adafruit invests time and resources providing this open source code, 
00014   please support Adafruit and open-source hardware by purchasing 
00015   products from Adafruit!
00016 
00017   Written by Limor Fried/Ladyada for Adafruit Industries.  
00018   BSD license, all text above must be included in any redistribution
00019  ****************************************************/
00020  
00021  /*
00022  *  Modified by Luiz Hespanha (http://www.d3.do) 8/16/2013 for use in LPC1768
00023  */
00024 
00025 #include "mbed.h"
00026 #include "Adafruit_LEDBackpack.h"
00027 #include "Adafruit_GFX.h"
00028 
00029 void Adafruit_LEDBackpack::setBrightness(uint8_t b) {
00030   if (b > 15) b = 15;
00031   uint8_t c = 0xE0 | b;
00032   char foo[1];
00033   foo[0] = c;
00034   _i2c->write(i2c_addr, foo, 1); 
00035 }
00036 
00037 void Adafruit_LEDBackpack::blinkRate(uint8_t b) {
00038   if (b > 3) b = 0; // turn off if not sure
00039   uint8_t c = HT16K33_BLINK_CMD | HT16K33_BLINK_DISPLAYON | (b << 1);
00040   char foo[1];
00041   foo[0] = c;
00042   _i2c->write(i2c_addr, foo, 1);
00043 }
00044 
00045 Adafruit_LEDBackpack::Adafruit_LEDBackpack(I2C *i2c): _i2c(i2c) {
00046 }
00047 
00048 void Adafruit_LEDBackpack::begin(uint8_t _addr = 0x70) {
00049   i2c_addr = _addr << 1;
00050 
00051   char foo[1];
00052   foo[0] = 0x21;
00053 
00054   _i2c->write(i2c_addr, foo, 1);  // turn on oscillator
00055 
00056   blinkRate(HT16K33_BLINK_OFF);
00057   
00058   setBrightness(15); // max brightness
00059 }
00060 
00061 void Adafruit_LEDBackpack::writeDisplay(void) {
00062   char foo[17];
00063   foo[0] = 0x00;
00064   int j = 0;
00065   for (uint8_t i=1; i<=16; i+=2) {
00066     int x = displaybuffer[j] & 0xFF;
00067     foo[i] = x;
00068     int x2 = displaybuffer[j] >> 8;
00069     foo[i+1] = x2;
00070     j++;
00071   }
00072   _i2c->write(i2c_addr, foo, 17);
00073 }
00074 
00075 void Adafruit_LEDBackpack::clear(void) {
00076   for (uint8_t i=0; i<8; i++) {
00077     displaybuffer[i] = 0;
00078   }
00079 }
00080 
00081 Adafruit_8x8matrix::Adafruit_8x8matrix(I2C *i2c) : Adafruit_LEDBackpack(i2c), Adafruit_GFX(8, 8) {
00082 }
00083 
00084 void Adafruit_8x8matrix::drawPixel(int16_t x, int16_t y, uint16_t color) {
00085   if ((y < 0) || (y >= 8)) return;
00086   if ((x < 0) || (x >= 8)) return;
00087 
00088  // check rotation, move pixel around if necessary
00089   switch (getRotation()) {
00090   case 1:
00091     swap(x, y);
00092     x = 8 - x - 1;
00093     break;
00094   case 2:
00095     x = 8 - x - 1;
00096     y = 8 - y - 1;
00097     break;
00098   case 3:
00099     swap(x, y);
00100     y = 8 - y - 1;
00101     break;
00102   }
00103 
00104   // wrap around the x
00105   x += 7;
00106   x %= 8;
00107 
00108 
00109   if (color) {
00110     displaybuffer[y] |= 1 << x;
00111   } else {
00112     displaybuffer[y] &= ~(1 << x);
00113   }
00114 }