Diff: spk_oled_ssd1305.cpp

Revision:

0:76bb084fa033

Child:

1:dd3faa2ab1dd

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spk_oled_ssd1305.cpp	Sun Apr 15 16:51:01 2012 +0000
@@ -0,0 +1,234 @@
+// *spark audio-visual
+// OLED display using SSD1305 driver
+// Copyright *spark audio-visual 2012
+
+#include "spk_oled_ssd1305.h"
+#include "mbed.h"
+
+SPKDisplay::SPKDisplay(PinName mosiPin, PinName clkPin, PinName csPin, PinName dcPin, PinName resPin, Serial *debugSerial)
+{
+    bufferHasChanged = false;
+    
+    spi = new SPI(mosiPin, NC, clkPin);
+    spi->format(8,3);
+    spi->frequency(2000000);
+    
+    cs = new DigitalOut(csPin);
+    dc = new DigitalOut(dcPin);
+    res = new DigitalOut(resPin);
+    
+    // Link up debug Serial object
+    // Passing in shared object as debugging is shared between all DVI mixer functions
+    debug = debugSerial;
+    
+    setup();
+    
+    clearBuffer();
+    
+    if (debug) debug->printf("SPKDisplay loaded\n\r");
+}
+
+void SPKDisplay::clearBuffer()
+{
+    memset(buffer, 0, bufferCount);
+    bufferHasChanged = true;
+}
+
+void SPKDisplay::imageToBuffer()
+{
+    memcpy(buffer, image, bufferCount);
+    bufferHasChanged = true;
+}
+
+void SPKDisplay::clearBufferRow(int row)
+{
+    // Range check
+    if (row >= 8)
+    {
+        if (debug) debug->printf("SPKDisplay::clearBufferRow sent out of bounds row");
+        return;
+    }
+    int bStart = row*bufferWidth;
+    int bEnd = bStart + pixelWidth;
+
+    for (int bPos = bStart; bPos <= bEnd; bPos++)
+    {
+        buffer[bPos] = 0x00;
+    }
+    
+    bufferHasChanged = true;
+}
+
+void SPKDisplay::horizLineToBuffer(int y)
+{
+    if (y >= pixelHeight)
+    {
+        if (debug) debug->printf("SPKDisplay::clearBufferRow sent out of bounds y");
+        return;
+    }
+    
+    int row = (y*pixInPage) / pixelHeight;
+    int posInRow = y % pixInPage;
+    
+    int bStart = row*bufferWidth;
+    int bEnd = bStart + pixelWidth;
+    
+    for (int bPos = bStart; bPos <= bEnd; bPos++)
+    {
+        // Need to bitwise OR as setting single bit (the line) in byte (the row)
+        buffer[bPos] = buffer[bPos] | 0x01 << posInRow;
+    } 
+    
+    bufferHasChanged = true;
+}
+
+void SPKDisplay::textToBuffer(std::string message, int row)
+{
+    // Range check
+    if (row >= 8) row = 7;
+    int bStart = row*bufferWidth;
+    int bEnd = bStart + pixelWidth;
+
+    int bPos = bStart;
+    for (int i = 0; i < message.size(); i++)
+    {
+        char character = message.at(i);
+        
+        // Is it outside the range we have glyphs for?
+        if ((character < characterBytesStartChar) || (character > characterBytesEndChar))
+        {
+            // Treat as a space
+            for (int j = 0; j < 5; j++)
+            {
+                if (bPos >= bEnd) break;
+                buffer[bPos++] = 0x00;
+            }
+            
+            // Warn if not
+            if (debug)
+            {
+                if (character != ' ') debug->printf("No glyph for character %c at position %i", character, i);
+            }
+        }
+        // If not, typeset it!
+        else 
+        {
+            // Shift into our array's indexing
+            character -= characterBytesStartChar;
+            
+            // Write each byte's vertical column of 8bits into the buffer.
+            for (int j = 0; j < characterBytes[character][0]; j++)
+            {
+                if (bPos >= bEnd) break;
+                buffer[bPos++] = characterBytes[character][j+1];
+            }
+            
+            // Put 1px letter spacing at end
+            if (bPos >= bEnd) break;
+            buffer[bPos++] = 0x00; // 1 px letter spacing
+        }
+    }
+    
+    bufferHasChanged = true;
+}
+
+void SPKDisplay::sendBuffer()
+{
+    if (bufferHasChanged)
+    {
+        // Select the device by seting chip select low
+        *cs = 0;
+    
+        // Set to receive DATA not commands
+        *dc = 1;
+    
+        for (int i = 0; i < bufferCount; i++)
+        {
+            spi->write(buffer[i]);
+        }
+        
+        // Deselect the device
+        *cs = 1;
+        
+        bufferHasChanged = false;
+    }
+}
+
+void SPKDisplay::setup()
+{
+    // TASK: SCREEN OFF, Run pre-flight
+    
+    // Hard reset the OLED
+    *res = 0;
+    wait_ms(1);
+    *res = 1;
+
+    // Select the device by seting chip select low
+    *cs = 0;
+    
+    // Set to receive COMMANDS not data
+    *dc = 0;
+
+    spi->write(0xAE); // set display off
+    spi->write(0xD5); // set display clock divide ratio
+    spi->write(0xA0);
+    spi->write(0xA8); // set multiplex ratio
+    spi->write(0x3F); 
+    spi->write(0xD3); // set display offset
+    spi->write(0x00);
+    spi->write(0x40); // set display start line
+    spi->write(0xAD); // set master configuration
+    spi->write(0x8E);
+    spi->write(0xD8); // set area color mode
+    spi->write(0x05);
+    spi->write(0xA1); // set segment re-map
+    spi->write(0xC8); // set com output scan direction
+    spi->write(0xDA); // set com pins hardware configuration
+    spi->write(0x12);
+    spi->write(0x91); // set look-up table
+    spi->write(0x3F);
+    spi->write(0x3F);
+    spi->write(0x3F);
+    spi->write(0x3F);
+    spi->write(0x81); // set current control for bank 0
+    spi->write(0x8F);
+    spi->write(0xD9); // set pre-charge period
+    spi->write(0xD2);
+    spi->write(0xDB); //set vcomh deselect level
+    spi->write(0x34);
+    spi->write(0xA4); // set entire display on/off
+    spi->write(0xA6); // set normal/inverse display
+    
+    spi->write(0x20); // page mode
+    spi->write(0x00);
+    
+    // TASK: Clear screen's content buffer
+    
+    // Is this neccessary when switching command/data?
+    *cs = 1;
+    wait_ms(1);
+    *cs = 0;
+    
+    // Set to receive DATA not commands
+    *dc = 1;
+        
+    for (int i = 0; i < bufferCount; i++)
+    {
+        spi->write(0x00);
+    }
+    
+    // TASK: SCREEN ON
+    
+    // Is this neccessary when switching command/data?
+    *cs = 1;
+    wait_ms(1);
+    *cs = 0;
+    
+    // Set to receive COMMANDS not data
+    *dc = 0;
+    
+    spi->write(0xAF); // set display on
+  
+    // Deselect the device
+    *cs = 1;
+}
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