main.cpp

00001 #include "mbed.h"
00002 #include <math.h>
00003 #include "main.h"
00004 #include "SDFileSystem.h"
00005 
00006 #define TEXT_LEVEL 5
00007 
00008 #define TX 24  // number of characters in X
00009 #define TY 10  // number of characters in Y
00010 
00011 #define CHECK_BIT(var,pos) ((var) & (1<<(pos)))
00012 #define MIN(a,b) (((a)<(b))?(a):(b))
00013 #define MAX(a,b) (((a)>(b))?(a):(b))
00014 
00015 
00016 // DAC stuff
00017 #define DAC_SYNC 2
00018 
00019 uint8_t char_col = 0;  // current column counter
00020 uint8_t char_row = 0;  // current row counter
00021 
00022 Serial pc(USBTX, USBRX);
00023 
00024 #include "vincent_data.h"
00025 
00026 //DigitalOut sout(D8); //sync PA_9
00027 //DigitalOut vout(D7); //video PA_8
00028 
00029 DigitalOut dac0(PA_4);
00030 DigitalOut dac1(PA_5);
00031 DigitalOut dac2(PA_6);
00032 DigitalOut dac3(PA_7);
00033 
00034 DigitalOut user_led(PB_14);
00035 int led_state = 1;
00036 
00037 // trigger horizontal line draw
00038 Ticker t;
00039 
00040 uint8_t bl_line_s[H_RES]; //blank line sync buffer
00041 uint8_t bl_line_v[H_RES]; //blank line video buffer
00042 uint8_t vb_line_s[H_RES]; //vertical sync, sync buffer
00043 uint8_t vb_line_v[H_RES]; //vertical sync, video buffer
00044 uint8_t im_line_s[H_RES]; //image sync buffer
00045 
00046 //buffers
00047 uint8_t current_frame[YL][XL / 2];
00048 uint8_t im_line_va_1[H_RES*V_RES];
00049 uint8_t im_line_va_2[H_RES*V_RES];
00050 
00051 //double buffered drawing
00052 uint8_t* im_line_va;
00053 uint8_t* im_back;
00054 
00055 uint16_t l=0; //current line of scan
00056 uint32_t tics = 0; //timer
00057 
00058 // positive or negative?
00059 int16_t sign(int16_t a)
00060 {
00061     if(a > 0) return 1;
00062     if(a < 0) return -1;
00063     return 0;
00064 }
00065 
00066 // clear the screen and the text buffer
00067 void clr()
00068 {
00069     for(int i = 0; i < H_RES; i++)
00070         for(int j = 0; j < V_RES; j++)
00071             im_line_va[i+j*H_RES] = 0;    
00072 }
00073 
00074 // initialize video buffers
00075 void init_buffers()
00076 {
00077     clr(); // zero buffers
00078     for(int i = 0; i < H_RES; i++)
00079     {
00080         im_line_s[i] = DAC_SYNC;   
00081         bl_line_s[i] = DAC_SYNC;
00082         bl_line_v[i] = 0;
00083         vb_line_s[i] = 0;
00084         vb_line_v[i] = 0;
00085     }    
00086     im_line_s[0] = 0;
00087     im_line_s[1] = 0;
00088     im_line_s[2] = 0;
00089     im_line_s[3] = 0;
00090     
00091     for(int i = 0; i < 15; i++) im_line_s[i] = 0;
00092     
00093     bl_line_s[0] = 0;
00094     vb_line_s[0] = DAC_SYNC;
00095     bl_line_s[1] = 0;
00096     vb_line_s[1] = DAC_SYNC;
00097     
00098     bl_line_s[3] = 0;
00099     vb_line_s[3] = DAC_SYNC;
00100     bl_line_s[2] = 0;
00101     vb_line_s[2] = DAC_SYNC;
00102 }
00103 
00104 // video interrupt
00105 void isr()
00106 {
00107     uint8_t nop = 0, img = 0; //use nops or use wait_us
00108     uint8_t* sptr; //pointer to sync buffer for line
00109     uint8_t* vptr; //pointer to video buffer for line
00110     uint8_t* pptr; //porch
00111     
00112     if (l < V_PORCH_SIZE) {
00113         vptr = bl_line_v; 
00114         sptr = im_line_s;
00115         nop = 1;
00116     }
00117     else if (l < YL + V_PORCH_SIZE) {
00118         vptr = im_line_va + (l - 30) * H_RES; 
00119         sptr = im_line_s;
00120         nop = 1;
00121         img = 1;
00122     }
00123     else if (l < 254) { 
00124         vptr = bl_line_v; 
00125         sptr = bl_line_s; 
00126         nop = 0;
00127     } 
00128     else {
00129         vptr = vb_line_v;
00130         sptr = vb_line_s;
00131         nop = 1;
00132     }
00133     
00134     pptr = img ? bl_line_v : vptr;
00135     
00136     if (nop) {
00137         for (uint16_t i = 0; i < H_PORCH_SIZE; i++) {
00138             GPIOA->ODR = (pptr[i] + sptr[i]) << 4;
00139     
00140             asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");
00141             asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");
00142         }
00143         
00144         for (uint16_t i = 0; i < H_RES; i++) //loop over each column
00145         {
00146             GPIOA->ODR = (vptr[i] + sptr[i]) << 4;
00147     
00148             asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");
00149             asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");
00150         }
00151     } else {
00152         for(uint16_t i = 0; i < 12; i++) //loop over each column
00153         {
00154             GPIOA->ODR = sptr[i] << 4;
00155     
00156             asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");
00157             asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");
00158             asm("nop");asm("nop");asm("nop");asm("nop");
00159         }
00160     }
00161     
00162     //move to next line
00163     l++;
00164     tics++;
00165     if(l > 255) l = 0;
00166 }
00167 
00168 // draw letter
00169 void draw_vincent(uint16_t x0, uint16_t y0, uint8_t c)
00170 {
00171     if(c == 40) c = 41;
00172     else if(c == 41) c = 40;
00173     char* letter = vincent_data[c];
00174     for(uint16_t xp = 0; xp < 8; xp++)
00175     {
00176         for(uint16_t yp = 0; yp < 8; yp++)
00177         {
00178             im_line_va[H_RES*(yp+y0) + xp + x0] = CHECK_BIT(letter[yp],8-xp)?TEXT_LEVEL:0;
00179         }
00180     }
00181 }
00182 
00183 // draw string
00184 void draw_vincent_string(char* str)
00185 {
00186     for(int i = 0; i < strlen(str); i++)
00187     {
00188         if(str[i] == 0) return;
00189         char_col++; 
00190     if(char_col >= TX)
00191     {
00192         char_col = 0;
00193         char_row++;
00194     }
00195     if(char_row >= TY)
00196     {
00197         char_row = 0;
00198     }
00199     
00200     draw_vincent(X0 +2 + 8*char_col, Y0 + 14 + 8*char_row, 
00201         str[i]);
00202     }
00203 }
00204 
00205 void set_status_string(char* str)
00206 {
00207     uint8_t char_col_backup = char_col;
00208     uint8_t char_row_backup = char_row;
00209     char_col = 0;
00210     char_row = TY - 1;
00211     
00212     draw_vincent_string(str);
00213     
00214     char_col = char_col_backup;
00215     char_row = char_row_backup;
00216 }
00217 
00218 int main()
00219 {
00220     uint8_t *buf_swap_tmp;
00221     im_line_va = im_line_va_1;
00222     im_back = im_line_va_2;
00223     
00224     //init serial
00225     pc.baud(115200);
00226     pc.printf("derp!\r\n");
00227  
00228     //init buffers
00229     init_buffers();
00230     //init timer
00231     t.attach_us(&isr,64);
00232     
00233     /*init SD card, wait for card insertion*/ 
00234     SDFileSystem sd(DI, DO, SCK, CS, "sd");
00235     while (sd.disk_status()) {
00236         sd.disk_initialize();
00237         wait(0.5);
00238     }
00239     
00240     FILE *fp;
00241     
00242     fp = fopen("/sd/man.worm.starwars", "rb");
00243             
00244     uint32_t old_tics = tics;
00245     for(;;)
00246     { 
00247         if (feof(fp)) rewind(fp);
00248         fread(current_frame, 1, VIDEO_FRAME_SIZE, fp);
00249         for(int x = 0; x < XL; x += 2)
00250         {
00251             for(int y = 0; y < YL; y++)
00252             {
00253                im_back[H_RES*(y+Y0) + x + X0] = current_frame[YL - y][x >> 1] >> 4;
00254                im_back[H_RES*(y+Y0) + x + 1 + X0] = current_frame[YL - y][x >> 1];
00255             }
00256         }
00257         
00258         buf_swap_tmp = im_line_va;
00259         im_line_va = im_back;
00260         im_back = buf_swap_tmp;
00261         
00262         led_state = !led_state;
00263         user_led = led_state; 
00264 
00265         char status_string[20];
00266         sprintf(status_string, "%.1f", 15625.f / (float)(tics - old_tics));
00267         old_tics = tics;
00268         set_status_string(status_string);        
00269     }
00270 }
00271 
00272