Display drivers

An easyGUI display driver consists of only two simple c functions, initialization and data transfer. It can easily be adapted to the hardware in question, meaning that the display hardware can use any connection method (bus, ports, I²C, SPI, etc.) supported by the display controller.

The initialization part of the display driver is not really easyGUI relevant, but merely sets up the display hardware for the required display mode, transfer method, etc., and make an initial clearing of the display. Display contrast control (if required), back lighting and other secondary tasks can also conveniently be placed here. Only drivers for palette based color modes contain easyGUI specific code in the initialization part, as the preferred palette must be transferred to the display controller.

The data transfer part of the display driver moves display data from the internal display buffer to the display controller RAM memory. Data transfer is intelligent, i.e. only necessary data is transferred, that is data changed since last data transfer. This ensures minimal data traffic to the (potentially slower) display controller.

Both the initialization and data transfer parts of the display driver are plain C functions of limited size, which can freely be modified to suit specific demands of the target system hardware. The driver system is thus very flexible and easy to maintain.

We will assist you in the initial task of getting the display driver up and running, if you should encounter problems with our driver.

Many display controllers support multiple setups regarding color depth, color mode, display orientation, etc. As the easyGUI display driver is so simple it is a trivial task to adapt it to the preferred display mode. Furthermore easyGUI can be set up to almost any color depth / mode currently found in display controllers.

Some easyGUI display drivers support more than one type of display controller. This is because a particular display controller architecture is often found in many incarnations, with different manufacturer names and product codes.

Microprocessors with build in display controllers, like e.g. some ARM controllers, are handled just like stand-alone display controllers.

Display buffer

As standard easyGUI uses an intermediate display buffer in ordinary RAM. The display image is created in the buffer by the easyGUI library, and then transferred to the display controller memory, using the method programmed in the display driver. It is however possible to bypass this internal display buffer if the display controller buffer is directly mapped into the microcontroller memory space. As the easyGUI internal display buffer is organized exactly as the display controller RAM it is possible to let the easyGUI library write directly into display controller RAM. The display driver update task is then left empty, as there is no longer any data to transfer from internal buffer to display controller buffer.

The reason for the intermediate buffer in easyGUI is two-fold. Both reasons are rooted in the fact that an easyGUI structure (collection of items to display) can consist of many parts, which more or less overlap, e.g. a box containing texts and other components. In fact, this is often the case. The reasons are:

1. Many display controllers are very slow to write to, either because of the display controller itself, or because of the way it is hooked to the micro controller (like e.g. port access). So, to speed up the system, the minimum amount of actual display writing is sought.
2. Writing overlapping parts directly to the display controller RAM will result in flickering, because partial display images will be visible (albeit for very short times).

The first reason is not that relevant with the newer color based, relatively high resolution, display controllers, which are far more efficient in moving around display data than older designs. The second reason is less important, if the speed of the embedded system is high.

easyGUI driver libary

To quickly find a suitable easyGUI driver for your preferred LCD controller, please insert a controller number below:

µPD161607 AT32AP7000 AT91RM9200 AT91SAM9261 AT91SAM9263 AX6107 AX6108 AX6120 AX6963 BVGP D51E5TA7601 F5529 FLE Viper FSA506 H8S2378 HD61202 HX8238 HX8312 HX8345 HX8346 HX8347 HX8352A ILI9320 ILI9341 IST3015 KS0107B KS0108B KS0707 KS0708 KS0713 KS0715 KS0717 KS0718 KS0719 KS0723 KS0724 KS0728 KS0741 KS0755 KS0759 LC7981 LH155BA LH75400 LH75401 LH75410 LH75411 LH7A400 LPC 3230 LPC 3250 LPC1787 LPC2478 MPC5606S MX257 NJU6450 NJU6450A NJU6452 NJU6570 NJU6575 NJU6673 NJU6675 NJU6676 NJU6677 NJU6678 NJU6679 NT39016 NT7107 NT7108 NT7501 NT7502 NT7508 NT7532 NT7534 OSD35GN827A OTM2201A PCF8548 PCF8813 PIC24FJ256 PT6520 PXA320 R61505 R61509 R61526 RA8803 RA8822 RA8835 S1D10605 S1D10606 S1D10607 S1D10608 S1D10609 S1D13305 S1D13505 S1D13700 S1D13704 S1D13705 S1D13706 S1D13715 S1D13742 S1D13743 S1D13748 S1D13781 S1D13A04 S1D13A05 S1D15600 S1D15601 S1D15602 S1D15605 S1D15705 S1D15707 S1D15708 S1D15710 S1D15721 S6B0107 S6B0107A S6B0108 S6B0108A S6B0707 S6B0708 S6B0713 S6B0715 S6B0716 S6B0717 S6B0718 S6B0719 S6B0721 S6B0723 S6B0724 S6B0725 S6B0728 S6B0741 S6B0755 S6B0759 S6B1713 S6B2107 S6B2108 S6B33BL S6D0129 S6D0139 S6E63D6 SBN0064 SBN1661 SED1335 SED1374 SED1375 SED1520 SED1530 SED1565 SEPS525 SH1101A SH1123 SPFD5408 SPLC501 SPLC502 SSD01303 SSD0323 SSD1289 SSD1303 SSD1305 SSD1322 SSD1325 SSD1339 SSD1805 SSD1815 SSD1848 SSD1852 SSD1857 SSD1858 SSD1859 SSD1905 SSD1906 SSD1926 SSD1963 SSD2119 ST7529 ST7541 ST7561 ST7565 ST7565P ST7565R ST7565S ST7565V ST7567 ST7571 ST7586 ST7637 ST7715 ST7715R ST7920 T6963 TL0313 TL0324 TLS8201 TMPA900 TS7390 UC1601 UC1606 UC1608 UC1610 UC1611 UC1617 UC1698 UC1701 WG24064