Silicon Labs
Display driver for Sharp's range of SPI-driven memory LCD's, leveraging the power of asynchronous transfers. Currently supports LS013B7DH03, but easily extendable to other models as well.
Dependents: memLCD-Demo memLCD-Demo memLCD-Demo MemLCD-Temperature-Humidity-Demo ... more
Information
All examples in this repo are considered EXPERIMENTAL QUALITY, meaning this code has been created as one-off proof-of-concept and is suitable as a demonstration for experimental purposes only. This code will not be regularly maintained by Silicon Labs and there is no guarantee that these projects will work across all environments, SDK versions and hardware.
Caution
This library builds upon the asynchronous SPI interface provided by mbed, but not all platforms currently support this. So, make sure your platform is capable of asynchronous SPI (all Silicon Labs platforms are), otherwise you will get compiler errors!
Usage
The library is purposefully quite simple to use. To set it up, you initialize an SPI object and the required I/O pins, and call the library constructor with those. Make sure the display is powered on, enabled, and the inversion mode is set to external (EXTMODE is high).
setup
#define SCK PD2 #define MOSI PD0 DigitalOut CS(PD3); DigitalOut EXTCOM(PC4); SPI displaySPI(MOSI, NC, SCK); silabs::LS013B7DH03 display(&displaySPI, &CS, &EXTCOM);
You should also swap out the pin names for the relevant names on your platform.
After setup, you usually want to clear any static information left on the screen. To do that, you would call clearImmediate, and optionally provide a callback. The callback will get called when the clearing operation is complete and the display has been cleared. In this example, refreshCallback sets a global boolean 'refreshed' to true when called.
clearing the display
refreshed = false;
int result = display.clearImmediate(refreshCallback);
if(result == LS013B7DH03_OK) {
while(refreshed == false) sleep();
} else {
printf("Display error: %d", result);
}
Of course, instead of sleeping while the display is clearing, you could also just continue with the program, and check back whether the callback happened or not.
Then comes the fun part, actually writing stuff on the display! Since the display only supports one-way communication (i.e. you cannot read from it), it uses an internal frame buffer in RAM. So, to actually display something on the LCD, two steps need to happen: writing to the pixel buffer, and at the very end writing the pixel buffer to the LCD.
Pixelbuffer operations
The MemoryLCD library builds upon Simon Ford's TextDisplay library, which means you can use all of that functionality. Even printf is supported!
most important display operations
// Set one pixel at x=10, y=40 to the color White
display.pixel(10,40,White);
// print "I love mbed" at the character position x=4, y=5
// i.e. starting on row 5, 4 characters from the left border
display.locate(4,5);
display.printf("I love mbed!");
// show a bitmap at a given location
// Constraints: bitmap is 8-bit, MSB first, 1 bit per pixel. Width, height and starting coordinates must be divisible by 8.
// This example: show a bitmap which is 128 pixels wide and high, and start at location 0,0.
display.showBMP(&mbed_logo, 128, 128, 0, 0);
//Draw a line (really a 1px wide rectangle) from (4,10) until (4,15)
display.fill(4, 10, 1, 5, White);
Updating the LCD
Updating the LCD (i.e. moving the framebuffer to the display) happens much the same way as clearing it: asynchronously. To start the update, you call update() on the display, optionally providing a callback to be called after the whole update has happened. In the example below, refreshCallback sets a global boolean 'refreshed' to true when called. Signature: void refreshCallback(void);
updating the display
refreshed = false;
int result = display.update(refreshCallback);
if(result == LS013B7DH03_OK) {
while(refreshed == false) sleep();
} else {
printf("Display error: %d", result);
}
Full example
example program
#include "LS013B7DH03.h"
#include "mbed_logo.h"
/******************** Define I/O *****************************/
DigitalOut myled(LED1);
#define SCK PD2
#define MOSI PD0
DigitalOut CS(PD3);
DigitalOut EXTCOM(PC4);
DigitalOut EXTMODE(PD4);
DigitalOut DISP(PD5);
SPI displaySPI(MOSI, NC, SCK);
silabs::LS013B7DH03 display(&displaySPI, &CS, &EXTCOM);
/******************** Define Timers *****************************/
LowPowerTicker timeKeeping;
/***************** Define global variables **********************/
#define INIT_SECONDS 17600
volatile uint32_t prevSeconds = INIT_SECONDS, seconds = INIT_SECONDS;
volatile bool refreshed = false;
/***************** Define callback handlers *********************/
void secondsCallback(void);
void refreshCallback(void);
void secondsCallback(void) {
seconds++;
}
/**
* Callback for refresh completion
*/
void refreshCallback(void) {
refreshed = true;
}
/*************************** MAIN *******************************/
int main() {
// Enable the LCD
EXTMODE = 1;
DISP = 1;
// Start generating the 1Hz call for keeping time
timeKeeping.attach(&secondsCallback, 1.0f);
// Reset the LCD to a blank state. (All white)
refreshed = false;
display.clearImmediate(refreshCallback);
while(refreshed == false) sleep();
printf("Initialization done! \n");
// Apply mbed logo bitmap to the pixel buffer
display.showBMP((uint8_t*)mbed_enabled_logo, 128, 128, 0, 0);
display.printf("I like MBED!");
// Push update to the display
refreshed = false;
display.update(refreshCallback);
// Sleep while doing the transmit
while(refreshed == false) sleep();
// Go into clock mode
while(1) {
sleep();
// In clock mode, only update once per second
if(prevSeconds != seconds) {
display.locate(4,15);
display.printf("%02d:%02d:%02d", (seconds / 1200) % 24, (seconds / 60) % 60, seconds % 60);
if(refreshed == true) {
prevSeconds = seconds;
refreshed = false;
display.update(refreshCallback);
}
}
}
}
Datasheet
Datasheet for the LCD (hosted by Mouser)
Revision 11:0f8ae10b308d, committed 2015-08-12
- Comitter:
- stevew817
- Date:
- Wed Aug 12 14:06:07 2015 +0000
- Parent:
- 10:231fa7861d1f
- Commit message:
- Implement Paul Staron's enhancements to the display driver classes, from https://developer.mbed.org/users/star297/code/MemoryLCD/rev/b64f87859c57
Changed in this revision
diff -r 231fa7861d1f -r 0f8ae10b308d GraphicsDisplay.cpp
--- a/GraphicsDisplay.cpp Wed Aug 12 13:32:01 2015 +0000
+++ b/GraphicsDisplay.cpp Wed Aug 12 14:06:07 2015 +0000
@@ -5,6 +5,9 @@
#include "GraphicsDisplay.h"
+#define incx() x++, dxt += d2xt, t += dxt
+#define incy() y--, dyt += d2yt, t += dyt
+
const unsigned char FONT8x8[97][8] = {
{0x08,0x08,0x08,0x00,0x00,0x00,0x00,0x00}, // columns, rows, num_bytes_per_char
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00}, // space 0x20
@@ -118,7 +121,47 @@
}
void GraphicsDisplay::character(int column, int row, int value) {
- blitbit(column * 8, row * 8, 8, 8, (char*)&(FONT8x8[value - 0x1F][0]));
+ if(externalfont){ // send external font
+ unsigned int hor,vert,offset,bpl,j,i,b;
+ const unsigned char* sign;
+ unsigned char z,w;
+ if ((value < 31) || (value > 127)) return; // test char range
+ // read font parameter from start of array
+ offset = font[0]; // bytes / char
+ hor = font[1]; // get hor size of font
+ vert = font[2]; // get vert size of font
+ bpl = font[3]; // bytes per line
+ if (char_x + hor > width()) {
+ char_x = 0;
+ char_y = char_y + vert;
+ if (char_y >= height() - font[2]) {
+ char_y = 0;
+ }
+ }
+ window(char_x, char_y,hor,vert); // char box
+ sign = &font[((value -32) * offset) + 4]; // start of char bitmap
+ w = sign[0]; // width of actual char
+ for (j=0; j<vert; j++) { // vert line
+ for (i=0; i<hor; i++) { // horz line
+ z = sign[bpl * i + ((j & 0xF8) >> 3)+1];
+ b = 1 << (j & 0x07);
+ if (( z & b ) == 0x00) {
+ putp(_foreground);
+ }
+ else {
+ putp(_background);
+ }
+ }
+ }
+ if ((w + 2) < hor) { // x offset to next char
+ char_x += w + 2;
+ }
+ else char_x += hor;
+ }
+ // send default font
+ else {
+ blitbit(column * 8, row * 8, 8, 8, (char*)&(FONT8x8[value - 0x1F][0]));
+ }
}
void GraphicsDisplay::window(int x, int y, int w, int h) {
@@ -146,11 +189,38 @@
}
}
+void GraphicsDisplay::rect(int x0, int y0, int x1, int y1, int color) {
+ if (x1 > x0) hline(x0,x1,y0,color);
+ else hline(x1,x0,y0,color);
+ if (y1 > y0) vline(x0,y0,y1,color);
+ else vline(x0,y1,y0,color);
+ if (x1 > x0) hline(x0,x1,y1,color);
+ else hline(x1,x0,y1,color);
+ if (y1 > y0) vline(x1,y0,y1,color);
+ else vline(x1,y1,y0,color);
+ return;
+}
+
+void GraphicsDisplay::fillrect(int x0, int y0, int w, int h, int colour) {
+ unsigned long int index=0;
+ if (w < 0) {
+ x0 = x0 + w;
+ w = -w;
+ }
+ if (h < 0) {
+ y0 = y0 + h;
+ h = -h;
+ }
+ window(x0,y0,w,h);
+ int num = h*w;
+ for( index = 0; index<num; index++ ) {
+ putp(colour);
+ }
+ return;
+}
+
void GraphicsDisplay::fill(int x, int y, int w, int h, int colour) {
- window(x, y, w, h);
- for(int i=0; i<w*h; i++) {
- putp(colour);
- }
+ fillrect(x, y, w, h, colour);
}
void GraphicsDisplay::circle(int x, int y, int r,int colour){
@@ -174,7 +244,187 @@
}
}
-
+
+// To draw circle set a and b to the same values
+void GraphicsDisplay::ellipse(int xc, int yc, int a, int b, unsigned int colour)
+{
+ /* e(x,y) = b^2*x^2 + a^2*y^2 - a^2*b^2 */
+ int x = 0, y = b;
+ long a2 = (long)a*a, b2 = (long)b*b;
+ long crit1 = -(a2/4 + a%2 + b2);
+ long crit2 = -(b2/4 + b%2 + a2);
+ long crit3 = -(b2/4 + b%2);
+ long t = -a2*y; // e(x+1/2,y-1/2) - (a^2+b^2)/4
+ long dxt = 2*b2*x, dyt = -2*a2*y;
+ long d2xt = 2*b2, d2yt = 2*a2;
+
+ while (y>=0 && x<=a) {
+ pixel(xc+x, yc+y, colour);
+ if (x!=0 || y!=0)
+ pixel(xc-x, yc-y, colour);
+ if (x!=0 && y!=0) {
+ pixel(xc+x, yc-y, colour);
+ pixel(xc-x, yc+y, colour);
+ }
+ if (t + b2*x <= crit1 || // e(x+1,y-1/2) <= 0
+ t + a2*y <= crit3) // e(x+1/2,y) <= 0
+ incx();
+ else if (t - a2*y > crit2) // e(x+1/2,y-1) > 0
+ incy();
+ else {
+ incx();
+ incy();
+ }
+ }
+}
+// To draw circle set a and b to the same values
+void GraphicsDisplay::fillellipse(int xc, int yc, int a, int b, unsigned int colour)
+{
+ /* e(x,y) = b^2*x^2 + a^2*y^2 - a^2*b^2 */
+ int x = 0, y = b;
+ int rx = x, ry = y;
+ unsigned int width = 1;
+ unsigned int height = 1;
+ long a2 = (long)a*a, b2 = (long)b*b;
+ long crit1 = -(a2/4 + a%2 + b2);
+ long crit2 = -(b2/4 + b%2 + a2);
+ long crit3 = -(b2/4 + b%2);
+ long t = -a2*y; // e(x+1/2,y-1/2) - (a^2+b^2)/4
+ long dxt = 2*b2*x, dyt = -2*a2*y;
+ long d2xt = 2*b2, d2yt = 2*a2;
+ if (b == 0) {
+ fillrect(xc-a, yc, 2*a+1, 1, colour);
+ return;
+ }
+ while (y>=0 && x<=a) {
+ if (t + b2*x <= crit1 || // e(x+1,y-1/2) <= 0
+ t + a2*y <= crit3) { // e(x+1/2,y) <= 0
+ if (height == 1)
+ ; // draw nothing
+ else if (ry*2+1 > (height-1)*2) {
+ fillrect(xc-rx, yc-ry, width, height-1, colour);
+ fillrect(xc-rx, yc+ry+1, width, 1-height, colour);
+ ry -= height-1;
+ height = 1;
+ } else {
+ fillrect(xc-rx, yc-ry, width, ry*2+1, colour);
+ ry -= ry;
+ height = 1;
+ }
+ incx();
+ rx++;
+ width += 2;
+ } else if (t - a2*y > crit2) { // e(x+1/2,y-1) > 0
+ incy();
+ height++;
+ } else {
+ if (ry*2+1 > height*2) {
+ fillrect(xc-rx, yc-ry, width, height, colour);
+ fillrect(xc-rx, yc+ry+1, width, -height, colour);
+ } else {
+ fillrect(xc-rx, yc-ry, width, ry*2+1, colour);
+ }
+ incx();
+ incy();
+ rx++;
+ width += 2;
+ ry -= height;
+ height = 1;
+ }
+ }
+ if (ry > height) {
+ fillrect(xc-rx, yc-ry, width, height, colour);
+ fillrect(xc-rx, yc+ry+1, width, -height, colour);
+ } else {
+ fillrect(xc-rx, yc-ry, width, ry*2+1, colour);
+ }
+}
+
+
+void GraphicsDisplay::line(int x0, int y0, int x1, int y1, int colour) {
+ //window(x0, y, w, h);
+ int dx = 0, dy = 0;
+ int dx_sym = 0, dy_sym = 0;
+ int dx_x2 = 0, dy_x2 = 0;
+ int di = 0;
+ dx = x1-x0;
+ dy = y1-y0;
+
+ if (dx == 0) { /* vertical line */
+ if (y1 > y0) vline(x0,y0,y1,colour);
+ else vline(x0,y1,y0,colour);
+ return;
+ }
+ if (dx > 0) {
+ dx_sym = 1;
+ } else {
+ dx_sym = -1;
+ }
+ if (dy == 0) { /* horizontal line */
+ if (x1 > x0) hline(x0,x1,y0,colour);
+ else hline(x1,x0,y0,colour);
+ return;
+ }
+ if (dy > 0) {
+ dy_sym = 1;
+ } else {
+ dy_sym = -1;
+ }
+ dx = dx_sym*dx;
+ dy = dy_sym*dy;
+ dx_x2 = dx*2;
+ dy_x2 = dy*2;
+ if (dx >= dy) {
+ di = dy_x2 - dx;
+ while (x0 != x1) {
+
+ pixel(x0, y0, colour);
+ x0 += dx_sym;
+ if (di<0) {
+ di += dy_x2;
+ } else {
+ di += dy_x2 - dx_x2;
+ y0 += dy_sym;
+ }
+ }
+ pixel(x0, y0, colour);
+ } else {
+ di = dx_x2 - dy;
+ while (y0 != y1) {
+ pixel(x0, y0, colour);
+ y0 += dy_sym;
+ if (di < 0) {
+ di += dx_x2;
+ } else {
+ di += dx_x2 - dy_x2;
+ x0 += dx_sym;
+ }
+ }
+ pixel(x0, y0, colour);
+ }
+ return;
+}
+
+void GraphicsDisplay::hline(int x0, int x1, int y, int colour) {
+ int w;
+ w = x1 - x0 + 1;
+ window(x0,y,w,1);
+ for (int x=0; x<w; x++) {
+ putp(colour);
+ }
+ return;
+}
+
+void GraphicsDisplay::vline(int x, int y0, int y1, int colour) {
+ int h;
+ h = y1 - y0 + 1;
+ window(x,y0,1,h);
+ for (int y=0; y<h; y++) {
+ putp(colour);
+ }
+ return;
+}
+
void GraphicsDisplay::cls() {
fill(0, 0, width(), height(), _background);
}
diff -r 231fa7861d1f -r 0f8ae10b308d GraphicsDisplay.h
--- a/GraphicsDisplay.h Wed Aug 12 13:32:01 2015 +0000
+++ b/GraphicsDisplay.h Wed Aug 12 14:06:07 2015 +0000
@@ -30,8 +30,20 @@
virtual void putp(int colour);
virtual void cls();
+ virtual void rect(int x0, int y0, int x1, int y1, int colour);
+ virtual void fillrect(int x0, int y0, int w, int h, int colour);
+ // fill equals fillrect, name has been kept to not break compatibility
virtual void fill(int x, int y, int w, int h, int colour);
+
+ // To draw circle using ellipse, set a and b to the same values
+ virtual void ellipse(int xc, int yc, int a, int b, unsigned int colour);
+ virtual void fillellipse(int xc, int yc, int a, int b, unsigned int colour);
virtual void circle(int x, int y, int r, int colour);
+
+ virtual void hline(int x0, int x1, int y, int colour);
+ virtual void vline(int x0, int y0, int y1, int colour);
+ virtual void line(int x0, int y0, int x1, int y1, int colour);
+
virtual void blit(int x, int y, int w, int h, const int *colour);
virtual void blitbit(int x, int y, int w, int h, const char* colour);
diff -r 231fa7861d1f -r 0f8ae10b308d TextDisplay.cpp
--- a/TextDisplay.cpp Wed Aug 12 13:32:01 2015 +0000
+++ b/TextDisplay.cpp Wed Aug 12 14:06:07 2015 +0000
@@ -47,9 +47,23 @@
}
}
+void TextDisplay::set_font(const unsigned char * f) {
+ font = f;
+ if(font==NULL) {
+ externalfont = 0; // set display.font
+ locate(0, 0);
+ }
+ else{
+ externalfont = 1;
+ locate(0, 0);
+ }
+}
+
void TextDisplay::locate(int column, int row) {
_column = column;
_row = row;
+ char_x = column;
+ char_y = row;
}
int TextDisplay::_getc() {
diff -r 231fa7861d1f -r 0f8ae10b308d TextDisplay.h
--- a/TextDisplay.h Wed Aug 12 13:32:01 2015 +0000
+++ b/TextDisplay.h Wed Aug 12 14:06:07 2015 +0000
@@ -47,12 +47,21 @@
*/
virtual int columns() = 0;
+ // Sets external font usage, eg. dispaly.set_font(Arial12x12);
+ // This uses pixel positioning.
+ // display.set_font(NULL); returns to internal default font.
+ void set_font(const unsigned char * f);
+
+ // set position of the next character or string print.
+ // External font, set pixel x(column),y(row) position.
+ // internal(default) font, set character column and row position
+ virtual void locate(int column, int row);
+
// functions that come for free, but can be overwritten
/** clear screen
*/
virtual void cls();
- virtual void locate(int column, int row);
virtual void foreground(uint16_t colour);
virtual void background(uint16_t colour);
// putc (from Stream)
@@ -63,10 +72,16 @@
virtual int _putc(int value);
virtual int _getc();
-
+
+ // external font functions
+ const unsigned char* font;
+ int externalfont;
+
// character location
uint16_t _column;
uint16_t _row;
+ unsigned int char_x;
+ unsigned int char_y;
// colours
uint16_t _foreground;
