Display.cpp

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00032 
00033 #include "Display.hpp"
00034 
00035 /// @{
00036 /// Width and height of the display in pixels.
00037 static const int width = 128;
00038 static const int height = 64;
00039 /// @}
00040 
00041 Display::Display(PinName mosi, PinName miso, PinName sclk, PinName ssel,
00042                  PinName a0)
00043     : canvas_(width, height), spi(mosi, miso, sclk), cs(ssel, 1), a0(a0, 0) {
00044   spi.format(8, 3); // CPOL = 1, CPHA = 1
00045 }
00046 
00047 void Display::initialize() {
00048   sendCommand(0xA0);
00049   sendCommand(0xAE);
00050   sendCommand(0xC0);
00051   sendCommand(0xA2);
00052   sendCommand(0x2F);
00053   sendCommand(0x26);
00054   sendCommand(0x81);
00055   sendCommand(0x11);
00056   sendCommand(0xAF);
00057 }
00058 
00059 void Display::update() {
00060   const int rowsPerPage = 8;
00061   const int pages = height / rowsPerPage;
00062   sendCommand(0xAE);
00063   sendCommand(0x40);
00064   for (int page = 0; page < pages; ++page) {
00065     sendCommand(0xB0 + page);
00066     sendCommand(0x10);
00067     sendCommand(0x00);
00068     for (int column = 0; column < width; ++column) {
00069       uint8_t segment = 0;
00070       for (int pixel = 0; pixel < rowsPerPage; ++pixel) {
00071         segment <<= 1;
00072         if (canvas_.pixelEnabled(column,
00073                                  ((pages - 1 - page) * rowsPerPage) + pixel)) {
00074           segment |= 1;
00075         }
00076       }
00077       sendData(segment);
00078     }
00079   }
00080   sendCommand(0xAF);
00081 }
00082 
00083 void Display::sendCommand(uint8_t command) {
00084   cs = 0;
00085   a0 = 0;
00086   spi.write(command);
00087   cs = 1;
00088 }
00089 
00090 void Display::sendData(uint8_t data) {
00091   cs = 0;
00092   a0 = 1;
00093   spi.write(data);
00094   cs = 1;
00095 }