David Smart / Mbed 2 deprecated RA8875_Demo

Simple demo for the Raio RA8875 Based Display with a 4-wire SPI interface.

Dependencies:   mbed RA8875

RA8875 Based Display Controller

This page shows a simple demo program for a graphics library supporting a low cost display from buydisplay.com. While the module can be configured for support via I2C, 3-Wire SPI, 4-Wire SPI, 8-bit Parallel or 16-bit Parallel, the companion library only supports the 4-Wire SPI.

You can also find this display on the Components | RA8875 page.

Library

RA8875 Library

Display Pictures

While this image is sharp, the camera/lighting washed out the colors somewhat. /media/uploads/WiredHome/ra8875display.640x380.png

With careful study of the image below, you can see a number of solder-blob jumpers. These jumpers are described quite well in the manual, and configure the many different options. The specific unit shown here is the "entry point" model, it does not have touchscreen, SD card, extra Font memory, or the key pad interface. As you see in the top left, it is wired with an 8-signal ribbon cable (but note in the schematic that it only needs 6 as the two power and two ground are internally connected together in the module).

/media/uploads/WiredHome/ra8875displaymodulerr.jpg

Also note, that some configuration changes go beyond the jumpers. I decided to switch my configuration to 4-Wire SPI and had to remove R1, R2, and R3 (which were zero-ohm that shorted the SPI input pins to +v!). I also changed some of the solder-blob jumpers, but that was easy. Had I ordered the display with the support for 4-Wire SPI, that would not have been necessary.

Schematic

The library should be able to work with any SPI port, and the Chip Select pin is a simple DigitalOut pin, chosen from the unused pins on my baseboard.

/media/uploads/WiredHome/ra8875_display_schematic.png

Sample Program

#include "mbed.h"
#include "RA8875.h"

Serial pc(USBTX, USBRX);

int main()
{
    pc.baud(460800);    // I like a snappy terminal, so crank it up!
    pc.printf("\r\nRA8875 Test - Build " __DATE__ " " __TIME__ "\r\n");

    RA8875 lcd(p5, p6, p7, p12, NC, "tft");    // MOSI, MISO, SCK, /ChipSelect, /reset, name

    lcd.puts(0,0,
        "RA8875 lcd(p5, p6, p7, p12, NC, \"tft\");\r\n\r\n"
        "lcd.circle(       400,25,  25,  BrightRed);\r\n"
        "lcd.fillcircle(   400,25,  15,  RGB(128,255,128));\r\n"
        "lcd.ellipse(      440,75,  35,20, BrightBlue);\r\n"
        "lcd.fillellipse(  440,75,  25,10, Blue);\r\n"
        "lcd.triangle(     440,100, 475,110, 450,125, Magenta);\r\n"
        "lcd.filltriangle( 445,105, 467,111, 452,120, Cyan);\r\n"
        "lcd.rect(         400,130, 475,155,    Brown);\r\n"
        "lcd.fillrect(     405,135, 470,150,    Pink);\r\n"
        "lcd.roundrect(    410,160, 475,190, 10,8, Yellow);\r\n"
        "lcd.fillroundrect(415,165, 470,185,  5,3, Orange);\r\n"
        "lcd.line(         430,200, 460,230, RGB(0,255,0));\r\n"
        "for (i=0; i<=30; i+=5)\r\n"
        "    lcd.pixel(435+i,200+i, White);");

    lcd.circle(       400,25,  25,               BrightRed);
    lcd.fillcircle(   400,25,  15,               RGB(128,255,128));
    lcd.ellipse(      440,75,  35,20,            BrightBlue);
    lcd.fillellipse(  440,75,  25,10,            Blue);
    lcd.triangle(     440,100, 475,110, 450,125, Magenta);
    lcd.filltriangle( 445,105, 467,111, 452,120, Cyan);
    lcd.rect(         400,130, 475,155,          Brown);
    lcd.fillrect(     405,135, 470,150,          Pink);
    lcd.roundrect(    410,160, 475,190, 10,8,    Yellow);
    lcd.fillroundrect(415,165, 470,185,  5,3,    Orange);
    lcd.line(         430,200, 460,230,          RGB(0,255,0));
    for (i=0; i<=30; i+=5) 
        lcd.pixel(435+i,200+i, White);
    while (1)
        ;
}

main.cpp@2:2076d9cc6db9, 2014-01-17 (annotated)

Committer:
WiredHome
Date:
Fri Jan 17 17:24:52 2014 +0000
Revision:
2:2076d9cc6db9
Parent:
0:037b95a5cc85
Child:
3:ca6a1026c28e
Simplify the example, so it shows the program on the screen.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WiredHome 0:037b95a5cc85 1 #include "mbed.h"
WiredHome 0:037b95a5cc85 2
WiredHome 0:037b95a5cc85 3 #include "RA8875.h"
WiredHome 0:037b95a5cc85 4
WiredHome 0:037b95a5cc85 5
WiredHome 0:037b95a5cc85 6 Serial pc(USBTX, USBRX);
WiredHome 0:037b95a5cc85 7
WiredHome 0:037b95a5cc85 8 int main()
WiredHome 0:037b95a5cc85 9 {
WiredHome 2:2076d9cc6db9 10 int i;
WiredHome 2:2076d9cc6db9 11
WiredHome 0:037b95a5cc85 12 pc.baud(460800); // I like a snappy terminal, so crank it up!
WiredHome 0:037b95a5cc85 13 pc.printf("\r\nRA8875 Test - Build " __DATE__ " " __TIME__ "\r\n");
WiredHome 0:037b95a5cc85 14
WiredHome 0:037b95a5cc85 15 pc.printf("Turning on display\r\n");
WiredHome 2:2076d9cc6db9 16 RA8875 lcd(p5, p6, p7, p12, NC, "tft"); // MOSI, MISO, SCK, /ChipSelect, /reset, name
WiredHome 2:2076d9cc6db9 17
WiredHome 2:2076d9cc6db9 18 //lcd.Power(true); // display power is on, but the backlight is independent
WiredHome 2:2076d9cc6db9 19 //lcd.Backlight(1.0);
WiredHome 0:037b95a5cc85 20
WiredHome 2:2076d9cc6db9 21 lcd.puts(0,0,
WiredHome 2:2076d9cc6db9 22 "RA8875 lcd(p5, p6, p7, p12, NC, \"tft\");\r\n\r\n"
WiredHome 2:2076d9cc6db9 23 "lcd.circle( 400,25, 25, BrightRed);\r\n"
WiredHome 2:2076d9cc6db9 24 "lcd.fillcircle( 400,25, 15, RGB(128,255,128));\r\n"
WiredHome 2:2076d9cc6db9 25 "lcd.ellipse( 440,75, 35,20, BrightBlue);\r\n"
WiredHome 2:2076d9cc6db9 26 "lcd.fillellipse( 440,75, 25,10, Blue);\r\n"
WiredHome 2:2076d9cc6db9 27 "lcd.triangle( 440,100, 475,110, 450,125, Magenta);\r\n"
WiredHome 2:2076d9cc6db9 28 "lcd.filltriangle( 445,105, 467,111, 452,120, Cyan);\r\n"
WiredHome 2:2076d9cc6db9 29 "lcd.rect( 400,130, 475,155, Brown);\r\n"
WiredHome 2:2076d9cc6db9 30 "lcd.fillrect( 405,135, 470,150, Pink);\r\n"
WiredHome 2:2076d9cc6db9 31 "lcd.roundrect( 410,160, 475,190, 10,8, Yellow);\r\n"
WiredHome 2:2076d9cc6db9 32 "lcd.fillroundrect(415,165, 470,185, 5,3, Orange);\r\n"
WiredHome 2:2076d9cc6db9 33 "lcd.line( 430,200, 460,230, RGB(0,255,0));\r\n"
WiredHome 2:2076d9cc6db9 34 "for (i=0; i<=30; i+=5)\r\n"
WiredHome 2:2076d9cc6db9 35 " lcd.pixel(435+i,200+i, White);");
WiredHome 0:037b95a5cc85 36
WiredHome 2:2076d9cc6db9 37 lcd.circle( 400,25, 25, BrightRed);
WiredHome 2:2076d9cc6db9 38 lcd.fillcircle( 400,25, 15, RGB(128,255,128));
WiredHome 2:2076d9cc6db9 39 lcd.ellipse( 440,75, 35,20, BrightBlue);
WiredHome 2:2076d9cc6db9 40 lcd.fillellipse( 440,75, 25,10, Blue);
WiredHome 2:2076d9cc6db9 41 lcd.triangle( 440,100, 475,110, 450,125, Magenta);
WiredHome 2:2076d9cc6db9 42 lcd.filltriangle( 445,105, 467,111, 452,120, Cyan);
WiredHome 2:2076d9cc6db9 43 lcd.rect( 400,130, 475,155, Brown);
WiredHome 2:2076d9cc6db9 44 lcd.fillrect( 405,135, 470,150, Pink);
WiredHome 2:2076d9cc6db9 45 lcd.roundrect( 410,160, 475,190, 10,8, Yellow);
WiredHome 2:2076d9cc6db9 46 lcd.fillroundrect(415,165, 470,185, 5,3, Orange);
WiredHome 2:2076d9cc6db9 47 lcd.line( 430,200, 460,230, RGB(0,255,0));
WiredHome 2:2076d9cc6db9 48 for (i=0; i<=30; i+=5)
WiredHome 2:2076d9cc6db9 49 lcd.pixel(435+i,200+i, White);
WiredHome 0:037b95a5cc85 50 while (1)
WiredHome 0:037b95a5cc85 51 ;
WiredHome 0:037b95a5cc85 52 }