drivers/displays/bitmap/sharpmem/sharpmem.c

   1 /**************************************************************************/
   2 /*!
   3     @file     sharpmem.c
   4     @author   K. Townsend (microBuilder.eu)
   5
   6     @section  DESCRIPTION
   7
   8     Driver for Sharp Memory Displays.
   9
  10     This driver uses a bit-banged 3-pin SPI interface.  For the SPI
  11     interface, the select line (CS) is active high, and the clock
  12     line (SCK) is active high.
  13
  14     Note: The LCD expects the address and data
  15     bits to arrive LSB, though the M3 shifts the bits out MSB so they
  16     need to be switched in SW first.
  17
  18     @section  EXAMPLE
  19     @code
  20
  21     sharpmemInit();
  22     sharpmemEnable(true);
  23
  24     // Render some text and a line into the image buffer
  25     uint32_t i;
  26     sharpmemDrawString(1, 10, "5x8 System", Font_System5x8);
  27     sharpmemDrawString(1, 20, "7x8 System", Font_System7x8);
  28     for (i = 0; i < 96; i++)
  29     {
  30       sharpmemDrawPixel(i, i);
  31     }
  32
  33     while(1)
  34     {
  35       // Screen must be refreshed at least once per second
  36       sharpmemRefresh();
  37       systickDelay(1000);
  38     }
  39
  40     @endcode
  41
  42     @section  LICENSE
  43
  44     Software License Agreement (BSD License)
  45
  46     Copyright (c) 2010, microBuilder SARL
  47     All rights reserved.
  48
  49     Redistribution and use in source and binary forms, with or without
  50     modification, are permitted provided that the following conditions are met:
  51     1. Redistributions of source code must retain the above copyright
  52     notice, this list of conditions and the following disclaimer.
  53     2. Redistributions in binary form must reproduce the above copyright
  54     notice, this list of conditions and the following disclaimer in the
  55     documentation and/or other materials provided with the distribution.
  56     3. Neither the name of the copyright holders nor the
  57     names of its contributors may be used to endorse or promote products
  58     derived from this software without specific prior written permission.
  59
  60     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  61     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  62     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  63     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
  64     DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  65     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  66     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  67     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  68     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  69     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  70 */
  71 /**************************************************************************/
  72 #include <string.h>
  73
  74 #include "sharpmem.h"
  75
  76 #include "core/systick/systick.h"
  77 #include "core/gpio/gpio.h"
  78 #include "drivers/displays/smallfonts.h"
  79
  80 #define TOGGLE_VCOM   do { _sharpmem_vcom = _sharpmem_vcom ? 0x00 : SHARPMEM_BIT_VCOM; } while(0);
  81
  82 static uint8_t _sharpmembuffer[(SHARPMEM_LCDWIDTH * SHARPMEM_LCDHEIGHT) / 8];
  83 static volatile uint8_t _sharpmem_vcom = SHARPMEM_BIT_VCOM;
  84
  85 /*************************************************/
  86 /* Private Methods                               */
  87 /*************************************************/
  88
  89 /**************************************************************************/
  90 /*!
  91     @brief  Swaps the bit order from MSB to LSB, since the LCD expects LSB,
  92             but the M3 shifts bits out MSB.
  93 */
  94 /**************************************************************************/
  95 uint8_t sharpmemSwap(uint8_t data)
  96 {
  97   uint8_t out = 0;
  98   if (data)
  99   {
 100     if(data & 0x01) out |= 0x80;
 101     if(data & 0x02) out |= 0x40;
 102     if(data & 0x04) out |= 0x20;
 103     if(data & 0x08) out |= 0x10;
 104     if(data & 0x10) out |= 0x08;
 105     if(data & 0x20) out |= 0x04;
 106     if(data & 0x40) out |= 0x02;
 107     if(data & 0x80) out |= 0x01;
 108   }
 109
 110   return out;
 111 }
 112
 113 /*************************************************/
 114 void sharpmemSendByte(uint8_t data)
 115 {
 116   uint8_t i = 0;
 117
 118   // Make sure clock pin starts low
 119   CLR_SCLK;
 120
 121   // Write from MSB to LSB
 122   // LCD expects LSB first
 123   for (i=0; i<8; i++)
 124   {
 125     if (data & 0x80)
 126     {
 127       SET_MOSI;
 128     }
 129     else
 130     {
 131       CLR_MOSI;
 132     }
 133     // Clock is active high
 134     SET_SCLK;
 135     data <<= 1;
 136     __asm volatile("nop");
 137     CLR_SCLK;
 138   }
 139 }
 140
 141 /**************************************************************************/
 142 /*!
 143     @brief  Draws a single graphic character using the supplied font
 144 */
 145 /**************************************************************************/
 146 static void sharpmemDrawChar(uint16_t x, uint16_t y, const char c, struct FONT_DEF font)
 147 {
 148   uint8_t col, column[font.u8Width];
 149
 150   // Check if the requested character is available
 151   if ((c >= font.u8FirstChar) && (c <= font.u8LastChar))
 152   {
 153     // Retrieve appropriate columns from font data
 154     for (col = 0; col < font.u8Width; col++)
 155     {
 156       column[col] = font.au8FontTable[((c - 32) * font.u8Width) + col];    // Get first column of appropriate character
 157     }
 158   }
 159   else
 160   {
 161     // Requested character is not available in this font ... send a space instead
 162     for (col = 0; col < font.u8Width; col++)
 163     {
 164       column[col] = 0xFF;    // Send solid space
 165     }
 166   }
 167
 168   // Render each column
 169   uint16_t xoffset, yoffset;
 170   for (xoffset = 0; xoffset < font.u8Width; xoffset++)
 171   {
 172     for (yoffset = 0; yoffset < (font.u8Height + 1); yoffset++)
 173     {
 174       uint8_t bit = 0x00;
 175       bit = (column[xoffset] << (8 - (yoffset + 1)));     // Shift current row bit left
 176       bit = (bit >> 7);                                   // Shift current row but right (results in 0x01 for black, and 0x00 for white)
 177       if (bit)
 178       {
 179         sharpmemDrawPixel(x + xoffset, y + yoffset);
 180       }
 181     }
 182   }
 183 }
 184
 185 /*************************************************/
 186 /* Public Methods                                */
 187 /*************************************************/
 188
 189 /*************************************************/
 190 void sharpmemInit(void)
 191 {
 192   // Set control pins to output
 193   gpioSetDir(SHARPMEM_PORT, SHARPMEM_SCLK_PIN, 1);
 194   gpioSetDir(SHARPMEM_PORT, SHARPMEM_MOSI_PIN, 1);
 195   gpioSetDir(SHARPMEM_PORT, SHARPMEM_CS_PIN, 1);
 196   gpioSetDir(SHARPMEM_PORT, SHARPMEM_DISP_PIN, 1);
 197
 198   // Set pins to default state
 199   CLR_SCLK;
 200   CLR_MOSI;
 201   CLR_CS;
 202   CLR_DISP;
 203
 204   // Set the vcom bit to a defined state
 205   _sharpmem_vcom = SHARPMEM_BIT_VCOM;
 206
 207   // Clear the display and turn it off by default
 208   sharpmemClearScreen();
 209   sharpmemEnable(false);
 210 }
 211
 212 /**************************************************************************/
 213 /*!
 214     @brief Turns the display on or off (memory is retained even when the
 215            display is off)
 216
 217     @param[in]  enabled
 218                 Whether the display should be on (TRUE/1) or off (FALSE/0)
 219 */
 220 /**************************************************************************/
 221 void sharpmemEnable(bool enable)
 222 {
 223   if (enable)
 224   {
 225     SET_DISP;
 226   }
 227   else
 228   {
 229     CLR_DISP;
 230   }
 231 }
 232
 233 /**************************************************************************/
 234 /*!
 235     @brief Draws a single pixel in image buffer
 236
 237     @param[in]  x
 238                 The x position (0 based)
 239     @param[in]  y
 240                 The y position (0 based)
 241 */
 242 /**************************************************************************/
 243 void sharpmemDrawPixel(uint16_t x, uint16_t y)
 244 {
 245   if ((x >= SHARPMEM_LCDWIDTH) || (y >= SHARPMEM_LCDHEIGHT))
 246     return;
 247
 248   _sharpmembuffer[(y*SHARPMEM_LCDWIDTH + x) /8] |= (1 << x % 8);
 249 }
 250
 251 /**************************************************************************/
 252 /*!
 253     @brief Clears a single pixel in image buffer
 254
 255     @param[in]  x
 256                 The x position (0 based)
 257     @param[in]  y
 258                 The y position (0 based)
 259 */
 260 /**************************************************************************/
 261 void sharpmemClearPixel(uint16_t x, uint16_t y)
 262 {
 263   if ((x >= SHARPMEM_LCDWIDTH) || (y >= SHARPMEM_LCDHEIGHT))
 264     return;
 265
 266   _sharpmembuffer[(y*SHARPMEM_LCDWIDTH + x) /8] &= ~(1 << x % 8);
 267 }
 268
 269 /**************************************************************************/
 270 /*!
 271     @brief Gets the value (1 or 0) of the specified pixel from the buffer
 272
 273     @param[in]  x
 274                 The x position (0 based)
 275     @param[in]  y
 276                 The y position (0 based)
 277
 278     @return     1 if the pixel is enabled, 0 if disabled
 279 */
 280 /**************************************************************************/
 281 uint8_t sharpmemGetPixel(uint16_t x, uint16_t y)
 282 {
 283   if ((x >=SHARPMEM_LCDWIDTH) || (y >=SHARPMEM_LCDHEIGHT)) return 0;
 284   return _sharpmembuffer[(y*SHARPMEM_LCDWIDTH + x) /8] & (1 << x % 8) ? 1 : 0;
 285 }
 286
 287 /**************************************************************************/
 288 /*!
 289     @brief Clears the screen
 290 */
 291 /**************************************************************************/
 292 void sharpmemClearScreen()
 293 {
 294   memset(_sharpmembuffer, 0x00, (SHARPMEM_LCDWIDTH * SHARPMEM_LCDHEIGHT) / 8);
 295   // Send the clear screen command rather than doing a HW refresh (quicker)
 296   SET_CS;
 297   sharpmemSendByte(_sharpmem_vcom | SHARPMEM_BIT_CLEAR);
 298   sharpmemSendByte(0x00);
 299   TOGGLE_VCOM;
 300   CLR_CS;
 301 }
 302
 303 /**************************************************************************/
 304 /*!
 305     @brief Renders the contents of the pixel buffer on the LCD
 306 */
 307 /**************************************************************************/
 308 void sharpmemRefresh(void)
 309 {
 310   uint16_t i, totalbytes, currentline, oldline;
 311   totalbytes = (SHARPMEM_LCDWIDTH * SHARPMEM_LCDHEIGHT) / 8;
 312
 313   // Send the write command
 314   SET_CS;
 315   sharpmemSendByte(SHARPMEM_BIT_WRITECMD | _sharpmem_vcom);
 316   TOGGLE_VCOM;
 317
 318   // Send the address for line 1
 319   oldline = currentline = 1;
 320   sharpmemSendByte(sharpmemSwap(currentline));
 321
 322   // Send image buffer
 323   for (i=0; i<totalbytes; i++)
 324   {
 325     sharpmemSendByte(sharpmemSwap(_sharpmembuffer[i]));
 326     currentline = ((i+1)/(SHARPMEM_LCDWIDTH/8)) + 1;
 327     if(currentline != oldline)
 328     {
 329       // Send end of line and address bytes
 330       sharpmemSendByte(0x00);
 331       if (currentline <= SHARPMEM_LCDHEIGHT)
 332       {
 333         sharpmemSendByte(sharpmemSwap(currentline));
 334       }
 335       oldline = currentline;
 336     }
 337   }
 338
 339   // Send another trailing 8 bits for the last line
 340   sharpmemSendByte(0x00);
 341   CLR_CS;
 342 }
 343
 344 /**************************************************************************/
 345 /*!
 346     @brief  Draws a string using the supplied font data.
 347
 348     @param[in]  x
 349                 Starting x co-ordinate
 350     @param[in]  y
 351                 Starting y co-ordinate
 352     @param[in]  text
 353                 The string to render
 354     @param[in]  font
 355                 Pointer to the FONT_DEF to use when drawing the string
 356
 357     @section Example
 358
 359     @code
 360
 361     #include "drivers/displays/bitmap/sharpmem/sharpmem.h"
 362     #include "drivers/displays/smallfonts.h"
 363
 364     // Configure the pins and initialise the LCD screen
 365     sharpmemInit();
 366
 367     // Render some text on the screen
 368     sharpmemDrawString(1, 10, "5x8 System", Font_System5x8);
 369     sharpmemDrawString(1, 20, "7x8 System", Font_System7x8);
 370
 371     // Refresh the screen to see the results
 372     sharpmemRefresh();
 373
 374     @endcode
 375 */
 376 /**************************************************************************/
 377 void sharpmemDrawString(uint16_t x, uint16_t y, const char* text, struct FONT_DEF font)
 378 {
 379   uint8_t l;
 380   for (l = 0; l < strlen(text); l++)
 381   {
 382     sharpmemDrawChar(x + (l * (font.u8Width + 1)), y, text[l], font);
 383   }
 384 }