Diff: ssd1306.cpp

Revision:

0:21cb91208386

Child:

1:1d58d378221c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ssd1306.cpp	Tue Feb 05 09:46:58 2013 +0000
@@ -0,0 +1,207 @@
+
+#include "mbed.h"
+#include "ssd1306.h"
+
+SSD1306::SSD1306(PinName cs, PinName rs, PinName dc, PinName clk, PinName data)
+    : _spi(data, NC, clk), _cs(cs), _reset(rs), _dc(dc)
+{
+}
+
+void SSD1306::set_low_column(int v)
+{
+    _send_command(SSD1306_SETLOWCOLUMN | v);
+}
+
+void SSD1306::set_high_column(int v)
+{
+    _send_command(SSD1306_SETHIGHCOLUMN | v);
+}
+
+void SSD1306::set_start_line(int v)
+{
+    _send_command(SSD1306_SETSTARTLINE | v);
+}
+
+void SSD1306::off()
+{
+    _send_command(SSD1306_DISPLAYOFF);
+}
+
+void SSD1306::on()
+{
+    _send_command(SSD1306_DISPLAYON);
+}
+
+void SSD1306::invert(int i)
+{
+    _send_command(i ? 
+        SSD1306_INVERTDISPLAY :
+        SSD1306_NORMALDISPLAY);
+}
+
+void SSD1306::set_display_offset(int v)
+{
+    _send_command(SSD1306_SETDISPLAYOFFSET);
+    _send_command(v); 
+}
+
+void SSD1306::initialise()
+{
+ // Init
+    _reset = 1;
+    wait(0.01);
+    _reset = 0;
+    wait(0.10);
+    _reset = 1;
+    
+    off();
+    
+    set_low_column(0);
+    set_high_column(0);
+    set_start_line(0);
+    
+    _send_command(SSD1306_SETCONTRAST);
+    _send_command(0xCF); // chargepump, could be 0x9F for external 9V
+    
+    _send_command(0xA1); // setment remap 95 to 0 (??)
+    
+    invert(0);
+    
+    _send_command(SSD1306_DISPLAYALLON_RESUME);
+    _send_command(SSD1306_SETMULTIPLEX);    
+    _send_command(0x3F); // 1/64 duty
+    
+    set_display_offset(0);
+    
+    _send_command(SSD1306_SETDISPLAYCLOCKDIV);
+    _send_command(0x80); // suggested value = 0x80
+    _send_command(SSD1306_SETPRECHARGE);
+    _send_command(0xF1); // dc/dc, could be 0x22 for external 9V
+    _send_command(SSD1306_SETCOMPINS);
+    _send_command(0x12); // disable COM left/right remap
+    _send_command(SSD1306_SETVCOMDETECT);
+    _send_command(0x40); // apparently, 0x20 is default...
+    _send_command(SSD1306_MEMORYMODE);
+    _send_command(0x0); // act like KS0108
+    
+    // left-to-right scan
+    _send_command(SSD1306_SEGREMAP | 0x1);
+    _send_command(SSD1306_COMSCANDEC);
+    _send_command(SSD1306_CHARGEPUMP);
+    _send_command(0x14); // disable, for external 9v 0x10 disable
+   
+    // turn it on
+    on();
+}
+
+void SSD1306::update()
+{
+    set_low_column(0);
+    set_high_column(0);
+    set_start_line(0);
+    
+    for (int i = 0; i < 1024; i++)
+        _send_data(_screen[i]);
+}
+
+void SSD1306::set_pixel(int x, int y)
+{
+    if (x >= SSD1306_LCDWIDTH || y >= SSD1306_LCDHEIGHT) return;
+    
+    _screen[x + (y / 8) * 128] |= 1 << (y % 8);
+}
+
+void SSD1306::clear_pixel(int x, int y)
+{
+    if (x >= SSD1306_LCDWIDTH || y >= SSD1306_LCDHEIGHT) return;
+    
+    _screen[x + (y / 8) * 128] &= ~(1 << (y % 8));
+}
+
+void SSD1306::line(int x0, int y0, int x1, int y1) {
+  int steep = abs(y1 - y0) > abs(x1 - x0);
+  int t;
+  
+  if (steep) {
+    t = x0; x0 = y0; y0 = t;
+    t = x1; x1 = y1; y1 = t;
+  }
+
+  if (x0 > x1) {
+    t = x0; x0 = x1; x1 = t;
+    t = y0; y0 = y1; y1 = t;
+  }
+
+  int dx, dy;
+  
+  dx = x1 - x0;
+  dy = abs(y1 - y0);
+
+  int err = dx / 2;
+  int ystep;
+
+  if (y0 < y1) {
+    ystep = 1;
+  } else {
+    ystep = -1;}
+
+  for (; x0<x1; x0++) {
+    if (steep) {
+      set_pixel(y0, x0);
+    } else {
+      set_pixel(x0, y0);
+    }
+    err -= dy;
+    if (err < 0) {
+      y0 += ystep;
+      err += dx;
+    }
+  }
+}
+
+void SSD1306::draw_string(char *font, int x, int y, const char *string)
+{
+    _cursor_x = x;
+    _cursor_y = y;
+    
+    for (int i = 0; i < strlen(string); i++) 
+        draw_char(font, _cursor_x, _cursor_y, string[i]);
+}
+
+void SSD1306::draw_char(char *font, int x, int y, char c)
+{
+    int height = font[FONT_HEIGHT_OFFSET];
+    int max_width = font[FONT_SIZE_OFFSET];
+    int char_size_bytes = max_width * height + 1;
+    int char_width = font[(c - FONT_START) * char_size_bytes + FONT_DATA_OFFSET];
+    for (int i = 0; i < char_width; i++)
+        _screen[(x + i) + (y * SSD1306_LCDWIDTH)] = font[(c - FONT_START) * (char_size_bytes) + i + FONT_DATA_OFFSET + 1];
+    
+    _cursor_x = x + char_width;
+    _cursor_y = y;
+}
+
+void SSD1306::clear()
+{
+    for (int i = 0; i < 1024; i++)
+        _screen[i] = 0;
+}
+
+void SSD1306::_send_command(int code)
+{
+    _cs = 1;
+    _dc = 0;
+    _cs = 0;
+    _spi.write(code);
+    _cs = 1;
+}
+
+void SSD1306::_send_data(int value)
+{
+    _cs = 1;
+    _dc = 1;
+    _cs = 0;
+    _spi.write(value);
+    _cs = 1;
+}
+