SPKDisplay - A mbed display class and processing imaging tools for 128x64 OLEDs using the SSD1305 driver, connected via SPI. This variant drives a Unigraphics oled on the same driver but in page mode. Includes a simple 5x7 ascii font
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OLED driver and demo for Univision oled display 128x64.
Modified Toby Harris' code to run page mode addressing in 4 wire SPI on the Univision UG-2864HSWEG01 128X64 unit - often found for sale on ebay. That's where I got mine anyhow.
Wiring this was fairly straightforward but you really do have to ground all the unused pins EXCEPT for number 8 to get it to work.
Here's the layout - I made a little carrier using a 2x8 connector and a couple of headers mounted on a small piece of stripboard. You can see all the wire links that are used to ground the unused pins. It was pretty awkward setting the display to run in 4 wire spi - had to desolder and resolder three smd o ohm links on the back o fhte pcb - ended up using a microscope to see them.
Here is the output of the demo code.
In page mode the display is effectively divided up into 8 horizontal strips, each 8 pixels high so lends itself nicley to displaying text in a 5x7 font. I've included the 5x7 lcd font in the code below.
Code
Import programunivision_oled
driver demo for univision oled dispaly
#include "mbed.h" #include "4spi_oled_ssd1305.h" /* re writtten to cope with teh ssd1306 driven oled UG-2864HSWEG01 from univision wiring for test circuit OLED pins -FUNCTION-------MBED PINns 1 ----3.3V--- Vout (p40) 2 ----0.0V--- GND (p1) 3 ----------- GND (p1) 4 ----------- GND (p1) 5 ----------- GND (p1) 6 ----------- GND (p1) 7 ----------- GND (p1) 8 ----------- N/C 9 ----D1---- mosi (p5) 10 ---D0------sck(p7) 11 ----------- GND (p1) 12 ----------- GND (p1) 13 ---DC------ p10 14 ---RES----- p9 15 ---CS------ p8 */ DigitalOut myled(LED1); // Create object and load font //SPKDisplay( mosiPin, clkPin, csPin, dcPin, resPin, Serial *debugSerial) SPKDisplay screen(p5, p7, p8, p10, p9); int main() { char msg[22]; sprintf(msg," "); // 01234567890abcdefghij int i=0; while(1==1) { myled=1; // nice logo output screen.welcome(); wait(3); wait(2); for(i=0; i<5; i++) { myled=0; screen.inverse(); wait(1); screen.normal(); myled=1; wait(1); } screen.fontdemo(); myled=0; wait(5); screen.clearBuffer(); screen.sendBuffer(); myled=1; wait(0.5); myled=0; wait(0.5); for(i=0; i<8; i++) { sprintf(msg,"HELLO WORLD %d",i); screen.textToBuffer(msg, i); screen.sendBuffer(); screen.clearBuffer(); myled=1; wait(1); } } }
Diff: spk_oled_ssd1305.cpp
- Revision:
- 0:76bb084fa033
- Child:
- 1:dd3faa2ab1dd
diff -r 000000000000 -r 76bb084fa033 spk_oled_ssd1305.cpp --- /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; +} \ No newline at end of file