u8g_com_arduino_ssd_i2c.c

00001 /*
00002   
00003   u8g_com_arduino_ssd_i2c.c
00004 
00005   com interface for arduino (AND atmega) and the SSDxxxx chip (SOLOMON) variant 
00006   I2C protocol 
00007   
00008   ToDo: Rename this to u8g_com_avr_ssd_i2c.c
00009 
00010   Universal 8bit Graphics Library
00011   
00012   Copyright (c) 2012, olikraus@gmail.com
00013   All rights reserved.
00014 
00015   Redistribution and use in source and binary forms, with or without modification, 
00016   are permitted provided that the following conditions are met:
00017 
00018   * Redistributions of source code must retain the above copyright notice, this list 
00019     of conditions and the following disclaimer.
00020     
00021   * Redistributions in binary form must reproduce the above copyright notice, this 
00022     list of conditions and the following disclaimer in the documentation and/or other 
00023     materials provided with the distribution.
00024 
00025   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
00026   CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
00027   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
00028   MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
00029   DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
00030   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
00031   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 
00032   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
00033   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 
00034   CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
00035   STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
00036   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 
00037   ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.  
00038   
00039   Special pin usage:
00040     U8G_PI_I2C_OPTION   additional options
00041     U8G_PI_A0_STATE used to store the last value of the command/data register selection
00042     U8G_PI_SET_A0       1: Signal request to update I2C device with new A0_STATE, 0: Do nothing, A0_STATE matches I2C device
00043     U8G_PI_SCL      clock line (NOT USED)
00044     U8G_PI_SDA      data line (NOT USED)
00045     
00046     U8G_PI_RESET        reset line (currently disabled, see below)
00047 
00048   Protocol:
00049     SLA, Cmd/Data Selection, Arguments
00050     The command/data register is selected by a special instruction byte, which is sent after SLA
00051     
00052     The continue bit is always 0 so that a (re)start is equired for the change from cmd to/data mode
00053 */
00054 
00055 #include "u8g.h"
00056 
00057 #define I2C_SLA     (0x3c*2)
00058 //#define I2C_CMD_MODE  0x080
00059 #define I2C_CMD_MODE    0x000
00060 #define I2C_DATA_MODE   0x040
00061 
00062 #if defined(U8G_WITH_PINLIST)
00063 
00064 uint8_t u8g_com_arduino_ssd_start_sequence(u8g_t *u8g)
00065 {
00066   /* are we requested to set the a0 state? */
00067   if ( u8g->pin_list[U8G_PI_SET_A0] == 0 )
00068     return 1;   
00069   
00070   /* setup bus, might be a repeated start */
00071   if ( u8g_i2c_start(I2C_SLA) == 0 )
00072     return 0;
00073   if ( u8g->pin_list[U8G_PI_A0_STATE] == 0 )
00074   {
00075     if ( u8g_i2c_send_byte(I2C_CMD_MODE) == 0 )
00076       return 0;
00077   }
00078   else
00079   {
00080     if ( u8g_i2c_send_byte(I2C_DATA_MODE) == 0 )
00081       return 0;
00082   }
00083   
00084   
00085   u8g->pin_list[U8G_PI_SET_A0] = 0;
00086   return 1;
00087 }
00088 
00089 uint8_t u8g_com_arduino_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
00090 {
00091   switch(msg)
00092   {
00093     case U8G_COM_MSG_INIT:
00094       //u8g_com_arduino_digital_write(u8g, U8G_PI_SCL, HIGH);
00095       //u8g_com_arduino_digital_write(u8g, U8G_PI_SDA, HIGH);
00096       //u8g->pin_list[U8G_PI_A0_STATE] = 0;       /* inital RS state: unknown mode */
00097     
00098       u8g_i2c_init(u8g->pin_list[U8G_PI_I2C_OPTION]);
00099 
00100       break;
00101     
00102     case U8G_COM_MSG_STOP:
00103       break;
00104 
00105     case U8G_COM_MSG_RESET:
00106       /* Currently disabled, but it could be enable. Previous restrictions have been removed */
00107       /* u8g_com_arduino_digital_write(u8g, U8G_PI_RESET, arg_val); */
00108       break;
00109       
00110     case U8G_COM_MSG_CHIP_SELECT:
00111       u8g->pin_list[U8G_PI_A0_STATE] = 0;
00112       u8g->pin_list[U8G_PI_SET_A0] = 1;     /* force a0 to set again, also forces start condition */
00113       if ( arg_val == 0 )
00114       {
00115         /* disable chip, send stop condition */
00116     u8g_i2c_stop();
00117      }
00118       else
00119       {
00120         /* enable, do nothing: any byte writing will trigger the i2c start */
00121       }
00122       break;
00123 
00124     case U8G_COM_MSG_WRITE_BYTE:
00125       //u8g->pin_list[U8G_PI_SET_A0] = 1;
00126       if ( u8g_com_arduino_ssd_start_sequence(u8g) == 0 )
00127     return u8g_i2c_stop(), 0;
00128       if ( u8g_i2c_send_byte(arg_val) == 0 )
00129     return u8g_i2c_stop(), 0;
00130       // u8g_i2c_stop();
00131       break;
00132     
00133     case U8G_COM_MSG_WRITE_SEQ:
00134       //u8g->pin_list[U8G_PI_SET_A0] = 1;
00135       if ( u8g_com_arduino_ssd_start_sequence(u8g) == 0 )
00136     return u8g_i2c_stop(), 0;
00137       {
00138         register uint8_t *ptr = arg_ptr;
00139         while( arg_val > 0 )
00140         {
00141       if ( u8g_i2c_send_byte(*ptr++) == 0 )
00142         return u8g_i2c_stop(), 0;
00143           arg_val--;
00144         }
00145       }
00146       // u8g_i2c_stop();
00147       break;
00148 
00149     case U8G_COM_MSG_WRITE_SEQ_P:
00150       //u8g->pin_list[U8G_PI_SET_A0] = 1;
00151       if ( u8g_com_arduino_ssd_start_sequence(u8g) == 0 )
00152     return u8g_i2c_stop(), 0;
00153       {
00154         register uint8_t *ptr = arg_ptr;
00155         while( arg_val > 0 )
00156         {
00157       if ( u8g_i2c_send_byte(u8g_pgm_read(ptr)) == 0 )
00158         return 0;
00159           ptr++;
00160           arg_val--;
00161         }
00162       }
00163       // u8g_i2c_stop();
00164       break;
00165       
00166     case U8G_COM_MSG_ADDRESS:                     /* define cmd (arg_val = 0) or data mode (arg_val = 1) */
00167       u8g->pin_list[U8G_PI_A0_STATE] = arg_val;
00168       u8g->pin_list[U8G_PI_SET_A0] = 1;     /* force a0 to set again */
00169     
00170 #ifdef OLD_CODE    
00171       if ( i2c_state != 0 )
00172       {
00173     u8g_i2c_stop();
00174     i2c_state = 0;
00175       }
00176 
00177       if ( u8g_com_arduino_ssd_start_sequence(arg_val) == 0 )
00178     return 0;
00179     
00180       /* setup bus, might be a repeated start */
00181       /*
00182       if ( u8g_i2c_start(I2C_SLA) == 0 )
00183     return 0;
00184       if ( arg_val == 0 )
00185       {
00186     i2c_state = 1;
00187     
00188     if ( u8g_i2c_send_byte(I2C_CMD_MODE) == 0 )
00189       return 0;
00190       }
00191       else
00192       {
00193     i2c_state = 2;
00194     if ( u8g_i2c_send_byte(I2C_DATA_MODE) == 0 )
00195       return 0;
00196       }
00197       */
00198 #endif
00199       break;
00200   }
00201   return 1;
00202 }
00203 
00204 #else  /* defined(U8G_WITH_PINLIST) */
00205 
00206 uint8_t u8g_com_arduino_ssd_i2c_fn(u8g_t *u8g, uint8_t msg, uint8_t arg_val, void *arg_ptr)
00207 {
00208   return 1;
00209 }
00210 
00211 #endif /* defined(U8G_WITH_PINLIST) */
00212 
00213