Paul Evans
Newhaven 320x240 LCD
Diff: newhaven.cpp
- Revision:
- 4:aa6dc362b462
- Parent:
- 3:1cf3ec6c70d7
--- a/newhaven.cpp Sun Feb 27 23:30:14 2011 +0000
+++ b/newhaven.cpp Mon Feb 28 17:48:12 2011 +0000
@@ -21,6 +21,12 @@
while(i--);
}
+void swap(int* a, int* b){
+ int temp = *a;
+ *a = *b;
+ *b = temp;
+}
+
// send commands to the LCD
void NHLCD::comm_out(unsigned char j){
LCD_PORT->output(); // sets the buffer to output data
@@ -29,7 +35,7 @@
CS = 0; // active LOW chip select
RW = 0; // set to 0 for write operation
E = 1; // operation enable
- delay(1); // wait for operation to complete
+ //delay(1); // wait for operation to complete
E = 0; // reset values
RW = 1;
CS = 1;
@@ -43,7 +49,7 @@
CS = 0; // active LOW chip select
RW = 0; // set to 0 for write operation
E = 1; // operation enable
- delay(1); // wait for operation to complete
+ //delay(1); // wait for operation to complete
E = 0; // reset values
RW = 1;
CS = 1;
@@ -84,31 +90,59 @@
/* set an individual pixel on the screen.
* pixels are grouped in bytes, so you must isolate a particular pixel.
*/
-void NHLCD::setPixel(int row, int col){
- int loc = (0x04<<8)|(0xB0); //sets location to the top left corner of drawing screen
- int c = loc+row*40+(col/8); // gets address of the correct byte
- comm_out(0x46); // command to set cursor location
- data_out((unsigned char)(c&0xFF)); // lower 8 bits of address
- data_out((unsigned char)((c&0xFF00)>>8)); // upper 8 bits of address
- comm_out(0x43); // command to read the byte
- LCD_PORT->input(); // sets the buffer to input data
- unsigned char buffer = LCD_PORT->read(); // stores byte in buffer
- buffer = buffer|(1<<(7-((row*320+col)%8))); // sets the particular pixel on the byte
- LCD_PORT->output(); // sets the buffer to output data
-
- comm_out(0x46); //command to set cursor location
- data_out((unsigned char)(c&0xFF)); // lower 8 bits of address
- data_out((unsigned char)((c&0xFF00)>>8)); // upper 8 bits of address
- comm_out(0x42); // command to write to the screen
- data_out(buffer); // write buffer to the screen
+void NHLCD::setPixel(int row, int col, int color){
+ int c = row*40+(col/8); // get location in buffer
+ char x = 1<<(7-(col%8)); // sets the bit to alter
+ if (color) // to mark the bit
+ screenBuffer[c] |= x; // marks the bit
+ else // to clear the bit
+ screenBuffer[c] &= ~x; // clears the bit
+ LCD_PORT->output(); // sets the buffer to output data
+ int loc = c+0x4B0; // get location on drawing screen
+ comm_out(0x46); // command to set cursor location
+ data_out((unsigned char)(loc&0xFF)); // lower 8 bits of address
+ data_out((unsigned char)((loc&0xFF00)>>8)); // upper 8 bits of address
+ comm_out(0x42); // command to write data
+ data_out(screenBuffer[c]); // write byte to the screen
+}
+
+// draw a line -- Bresenham's line algorithm
+void NHLCD::drawLine(int r1, int c1, int r2, int c2, int color){
+ int w = r2 - r1; // calculate width of line
+ int h = c2 - c1; // calculate height of line
+ double ratio;
+ int x, y;
+ int upright = 0; // assumes the line is "wide"
+ if (abs(h) > abs(w)) { // checks if height is greater than width
+ upright = 1; // if it is, the line is "tall"
+ swap(&c1, &r1); // mirrors coordinates over the line y=x to make it "wide"
+ swap(&c2, &r2);
+ swap(&w, &h);
+ }
+ if (r1 > r2) { // if the first row is on the right, swaps start and end coordinates
+ swap(&c1, &c2); // now the line is always drawn from "bottom-left" to "top-right"
+ swap(&r1, &r2);
+ }
+ ratio = ((double) h) / w; // calculates ratio of height to width
+ for (x = r1; x < r2; x++) { // iterates through the rows
+ y = c1 + (x - r1) * ratio; // calculates the height at this particular row
+ if (upright) setPixel(y, x, color); // depending on if the line is "wide" or "tall", you have to
+ else setPixel(x, y, color); // call setPixel differently
+ }
+}
+
+// draw and fill a rectangle
+void NHLCD::fillRect(int row, int col, int height, int width, int color){
+ for (int r = 0; r < height; r++) // iterate through each row
+ for (int c = 0; c < width; c++) // iterate through each column
+ setPixel(row+r,col+c,color); // set each pixel in the rectangle
}
// initialize the LCD
void NHLCD::Init(void){
- /* reset the device */
- RST = 0;
+ RST = 0; // resets the device
delay(5);
- RST = 1;
+ RST = 1; // restarts it
delay(10);
comm_out(0x40); // system set command
@@ -117,7 +151,7 @@
data_out(0x87); // horizontal character size (0x80 = 1) MUST BE MULTIPLE OF 320
data_out(0x07); // vertical character size (0x00 = 1) MUST BE MULTIPLE OF 240
data_out(40); // addresses per line
- data_out(80); // bytes per line
+ data_out(80); // words per line
data_out(0xEF); // 240 displace lines
data_out(0x28); // virtual address 1
data_out(0x00); // virtual address 2
@@ -151,5 +185,7 @@
comm_out(0x59); // disp on/off
data_out(0x16); // on
- wait_ms(5);
+
+ for(int i = 0; i < 40*240; i++)
+ screenBuffer[i] = 0;
}