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Rev | Author | Line No. | Line |
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1702 | - | 1 | // Code to copy a MCM font file to the Arduino + Max7456 OSD |
2 | // |
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3 | // MAX7456_font Sketch |
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4 | // at 9600 baud it take about 3min to download a mcm file |
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5 | // http://www.maxim-ic.com/tools/evkit/index.cfm?EVKit=558 |
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6 | // max7456 evaluation kit software |
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7 | |||
8 | #define DATAOUT 11//11-MOSI |
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9 | #define DATAIN 12//12-MISO |
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10 | #define SPICLOCK 13//13-sck |
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11 | #define MAX7456SELECT 6 //6 |
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12 | #define USBSELECT 10//10-ss |
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13 | #define VSYNC 2// INT0 |
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14 | |||
15 | //MAX7456 opcodes |
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16 | #define VM0_reg 0x00 |
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17 | #define VM1_reg 0x01 |
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18 | #define DMM_reg 0x04 |
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19 | #define DMAH_reg 0x05 |
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20 | #define DMAL_reg 0x06 |
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21 | #define DMDI_reg 0x07 |
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22 | #define CMM_reg 0x08 |
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23 | #define CMAH_reg 0x09 |
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24 | #define CMAL_reg 0x0A |
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25 | #define CMDI_reg 0x0B |
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26 | #define STAT_reg 0xA0 |
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27 | |||
28 | //MAX7456 commands |
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29 | #define CLEAR_display 0x04 |
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30 | #define CLEAR_display_vert 0x06 |
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31 | #define END_string 0xff |
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32 | #define WRITE_nvr 0xa0 |
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33 | // with NTSC |
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34 | #define ENABLE_display 0x08 |
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35 | #define ENABLE_display_vert 0x0c |
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36 | #define MAX7456_reset 0x02 |
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37 | #define DISABLE_display 0x00 |
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38 | |||
39 | // with PAL |
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40 | // all VM0_reg commands need bit 6 set |
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41 | //#define ENABLE_display 0x48 |
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42 | //#define ENABLE_display_vert 0x4c |
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43 | //#define MAX7456_reset 0x42 |
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44 | //#define DISABLE_display 0x40 |
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45 | |||
46 | #define WHITE_level_80 0x03 |
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47 | #define WHITE_level_90 0x02 |
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48 | #define WHITE_level_100 0x01 |
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49 | #define WHITE_level_120 0x00 |
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50 | |||
51 | #define MAX_font_rom 0xff |
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52 | #define STATUS_reg_nvr_busy 0x20 |
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53 | #define NVM_ram_size 0x36 |
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54 | |||
55 | // with NTSC |
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56 | #define MAX_screen_rows 0x0d //13 |
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57 | |||
58 | // with PAL |
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59 | //#define MAX_screen_rows 0x10 //16 |
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60 | |||
61 | volatile byte screen_buffer[MAX_font_rom]; |
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62 | volatile byte character_bitmap[0x40]; |
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63 | volatile byte ascii_binary[0x08]; |
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64 | |||
65 | volatile byte bit_count; |
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66 | volatile byte byte_count; |
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67 | volatile int font_count; |
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68 | volatile int incomingByte; |
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69 | volatile int count; |
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70 | |||
71 | |||
72 | ////////////////////////////////////////////////////////////// |
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73 | void setup() |
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74 | { |
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75 | byte spi_junk; |
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76 | int x; |
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77 | Serial.begin(38400); |
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78 | Serial.flush(); |
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79 | |||
80 | digitalWrite(USBSELECT,HIGH); //disable USB chip |
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81 | |||
82 | pinMode(MAX7456SELECT,OUTPUT); |
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83 | digitalWrite(MAX7456SELECT,HIGH); //disable device |
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84 | |||
85 | pinMode(DATAOUT, OUTPUT); |
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86 | pinMode(DATAIN, INPUT); |
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87 | pinMode(SPICLOCK,OUTPUT); |
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88 | pinMode(VSYNC, INPUT); |
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89 | |||
90 | // SPCR = 01010000 |
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91 | //interrupt disabled,spi enabled,msb 1st,master,clk low when idle, |
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92 | //sample on leading edge of clk,system clock/4 rate (4 meg) |
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93 | SPCR = (1<<SPE)|(1<<MSTR); |
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94 | spi_junk=SPSR; |
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95 | spi_junk=SPDR; |
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96 | delay(250); |
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97 | |||
98 | // force soft reset on Max7456 |
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99 | digitalWrite(MAX7456SELECT,LOW); |
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100 | spi_transfer(VM0_reg); |
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101 | spi_transfer(MAX7456_reset); |
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102 | digitalWrite(MAX7456SELECT,HIGH); |
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103 | delay(500); |
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104 | |||
105 | // set all rows to same character white level, 90% |
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106 | digitalWrite(MAX7456SELECT,LOW); |
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107 | for (x = 0; x < MAX_screen_rows; x++) |
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108 | { |
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109 | spi_transfer(x + 0x10); |
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110 | spi_transfer(WHITE_level_90); |
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111 | } |
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112 | |||
113 | // make sure the Max7456 is enabled |
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114 | spi_transfer(VM0_reg); |
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115 | spi_transfer(ENABLE_display); |
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116 | digitalWrite(MAX7456SELECT,HIGH); |
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117 | |||
118 | incomingByte = 0; |
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119 | count = 0; |
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120 | bit_count = 0; |
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121 | byte_count = 0; |
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122 | font_count = 0; |
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123 | |||
124 | //display all 256 internal MAX7456 characters |
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125 | for (x = 0; x < MAX_font_rom; x++) |
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126 | { |
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127 | screen_buffer[x] = x; |
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128 | } |
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129 | count = MAX_font_rom; |
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130 | write_new_screen(); |
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131 | |||
132 | Serial.println("Ready for text file download"); |
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133 | Serial.println(""); |
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134 | delay(100); |
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135 | } |
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136 | |||
137 | ////////////////////////////////////////////////////////////// |
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138 | void loop() |
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139 | { |
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140 | byte x; |
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141 | |||
142 | if (Serial.available() > 0) |
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143 | { |
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144 | // read the incoming byte: |
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145 | incomingByte = Serial.read(); |
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146 | |||
147 | switch(incomingByte) // parse and decode mcm file |
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148 | { |
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149 | case 0x0d: // carridge return, end of line |
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150 | //Serial.println("cr"); |
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151 | if (bit_count == 8 && (ascii_binary[0] == 0x30 || ascii_binary[0] == 0x31)) |
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152 | { |
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153 | // turn 8 ascii binary bytes to single byte '01010101' = 0x55 |
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154 | // fill in 64 bytes of character data |
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155 | character_bitmap[byte_count] = decode_ascii_binary(); |
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156 | byte_count++; |
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157 | bit_count = 0; |
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158 | } |
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159 | else |
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160 | bit_count = 0; |
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161 | break; |
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162 | case 0x0a: // line feed, ignore |
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163 | //Serial.println("ln"); |
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164 | break; |
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165 | case 0x30: // ascii '0' |
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166 | case 0x31: // ascii '1' |
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167 | ascii_binary[bit_count] = incomingByte; |
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168 | bit_count++; |
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169 | break; |
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170 | default: |
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171 | break; |
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172 | } |
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173 | } |
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174 | |||
175 | // we have one completed character |
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176 | // write the character to NVM |
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177 | if(byte_count == 64) |
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178 | { |
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179 | write_NVM(); |
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180 | byte_count = 0; |
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181 | font_count++; |
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182 | } |
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183 | |||
184 | // we have burned all 256 characters in NVM |
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185 | if(font_count == 256) |
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186 | { |
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187 | font_count = 0; |
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188 | |||
189 | // force soft reset on Max7456 |
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190 | digitalWrite(MAX7456SELECT,LOW); |
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191 | spi_transfer(VM0_reg); |
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192 | spi_transfer(MAX7456_reset); |
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193 | digitalWrite(MAX7456SELECT,HIGH); |
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194 | delay(500); |
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195 | |||
196 | // display all 256 new internal MAX7456 characters |
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197 | for (x = 0; x < MAX_font_rom; x++) |
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198 | { |
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199 | screen_buffer[x] = x; |
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200 | } |
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201 | count = MAX_font_rom; |
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202 | write_new_screen(); |
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203 | |||
204 | Serial.println(""); |
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205 | Serial.println("Done with file download"); |
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206 | } |
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207 | } |
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208 | |||
209 | ////////////////////////////////////////////////////////////// |
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210 | byte spi_transfer(volatile byte data) |
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211 | { |
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212 | SPDR = data; // Start the transmission |
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213 | while (!(SPSR & (1<<SPIF))) // Wait the end of the transmission |
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214 | { |
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215 | }; |
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216 | return SPDR; // return the received byte |
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217 | } |
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218 | |||
219 | ////////////////////////////////////////////////////////////// |
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220 | void write_new_screen() |
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221 | { |
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222 | int x, local_count; |
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223 | byte char_address_hi, char_address_lo; |
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224 | byte screen_char; |
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225 | |||
226 | local_count = count; |
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227 | |||
228 | char_address_hi = 0; |
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229 | char_address_lo = 60; // start on third line |
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230 | //Serial.println("write_new_screen"); |
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231 | |||
232 | // clear the screen |
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233 | digitalWrite(MAX7456SELECT,LOW); |
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234 | spi_transfer(DMM_reg); |
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235 | spi_transfer(CLEAR_display); |
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236 | digitalWrite(MAX7456SELECT,HIGH); |
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237 | |||
238 | // disable display |
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239 | digitalWrite(MAX7456SELECT,LOW); |
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240 | spi_transfer(VM0_reg); |
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241 | spi_transfer(DISABLE_display); |
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242 | |||
243 | spi_transfer(DMM_reg); //dmm |
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244 | //spi_transfer(0x21); //16 bit trans background |
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245 | spi_transfer(0x01); //16 bit trans w/o background |
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246 | |||
247 | spi_transfer(DMAH_reg); // set start address high |
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248 | spi_transfer(char_address_hi); |
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249 | |||
250 | spi_transfer(DMAL_reg); // set start address low |
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251 | spi_transfer(char_address_lo); |
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252 | |||
253 | x = 0; |
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254 | while(local_count) // write out full screen |
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255 | { |
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256 | screen_char = screen_buffer[x]; |
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257 | spi_transfer(DMDI_reg); |
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258 | spi_transfer(screen_char); |
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259 | x++; |
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260 | local_count--; |
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261 | } |
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262 | |||
263 | spi_transfer(DMDI_reg); |
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264 | spi_transfer(END_string); |
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265 | |||
266 | spi_transfer(VM0_reg); // turn on screen next vertical |
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267 | spi_transfer(ENABLE_display_vert); |
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268 | digitalWrite(MAX7456SELECT,HIGH); |
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269 | } |
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270 | |||
271 | ////////////////////////////////////////////////////////////// |
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272 | byte decode_ascii_binary() |
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273 | { |
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274 | byte ascii_byte; |
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275 | |||
276 | ascii_byte = 0; |
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277 | |||
278 | if (ascii_binary[0] == 0x31) // ascii '1' |
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279 | ascii_byte = ascii_byte + 128; |
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280 | |||
281 | if (ascii_binary[1] == 0x31) |
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282 | ascii_byte = ascii_byte + 64; |
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283 | |||
284 | if (ascii_binary[2] == 0x31) |
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285 | ascii_byte = ascii_byte + 32; |
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286 | |||
287 | if (ascii_binary[3] == 0x31) |
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288 | ascii_byte = ascii_byte + 16; |
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289 | |||
290 | if (ascii_binary[4] == 0x31) |
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291 | ascii_byte = ascii_byte + 8; |
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292 | |||
293 | if (ascii_binary[5] == 0x31) |
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294 | ascii_byte = ascii_byte + 4; |
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295 | |||
296 | if (ascii_binary[6] == 0x31) |
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297 | ascii_byte = ascii_byte + 2; |
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298 | |||
299 | if (ascii_binary[7] == 0x31) |
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300 | ascii_byte = ascii_byte + 1; |
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301 | |||
302 | //Serial.print(ascii_byte, HEX); |
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303 | |||
304 | return(ascii_byte); |
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305 | } |
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306 | |||
307 | ////////////////////////////////////////////////////////////// |
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308 | void write_NVM() |
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309 | { |
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310 | byte x; |
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311 | byte char_address_hi, char_address_lo; |
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312 | byte screen_char; |
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313 | |||
314 | char_address_hi = font_count; |
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315 | char_address_lo = 0; |
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316 | //Serial.println("write_new_screen"); |
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317 | |||
318 | // disable display |
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319 | digitalWrite(MAX7456SELECT,LOW); |
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320 | spi_transfer(VM0_reg); |
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321 | spi_transfer(DISABLE_display); |
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322 | |||
323 | spi_transfer(CMAH_reg); // set start address high |
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324 | spi_transfer(char_address_hi); |
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325 | |||
326 | for(x = 0; x < NVM_ram_size; x++) // write out 54 (out of 64) bytes of character to shadow ram |
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327 | { |
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328 | screen_char = character_bitmap[x]; |
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329 | spi_transfer(CMAL_reg); // set start address low |
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330 | spi_transfer(x); |
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331 | spi_transfer(CMDI_reg); |
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332 | spi_transfer(screen_char); |
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333 | } |
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334 | |||
335 | // transfer a 54 bytes from shadow ram to NVM |
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336 | spi_transfer(CMM_reg); |
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337 | spi_transfer(WRITE_nvr); |
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338 | |||
339 | // wait until bit 5 in the status register returns to 0 (12ms) |
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340 | while ((spi_transfer(STAT_reg) & STATUS_reg_nvr_busy) != 0x00); |
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341 | |||
342 | spi_transfer(VM0_reg); // turn on screen next vertical |
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343 | spi_transfer(ENABLE_display_vert); |
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344 | digitalWrite(MAX7456SELECT,HIGH); |
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345 | } |