Last update: 23. May 2006
Controller for Nokia 7650 cell phone
LCD Display, 176 *208 pixel, 4096 colors
Despite nobody seems to own the appropriate documentation, it is possible to use the big cheap color LCD displays of the Nokia series 60 cell phones for home brew projects. I don't even have the docs and it was a rough and painful way, but now it works.
A brief overview about the controller solution:
The Nokia 7650 LCD has a host interface which consists of an 8 bit bidirectional data bus and some control pins. Due to the unknown on-board controller instructions set, an image for the display is put together in the RAM area of an external controller (LPC2106, an ARM7TDMI-S). After the new image has been completed in RAM, a high speed data transfer from the LPC2106 image RAM to the display takes place. It lasts about 23ms.
Each pixel can be controlled by 12 bit to get a specific color. Each pixel of the existing 36608 pixel can be controlled individually. There is no color table, but there is a direct relation between a 12 bit value and a specific color.
The current controller SW supports upright and landscape character display. The characters can optional be displayed in transparent mode or with an own background color. Also characters can be displayed in a fixed raster or optionally in a "floating"raster.
There is a character set generator SW by Fabian Thiele. The font format of the LCD7650 controller is compatible to this tool. Each character can consist of an own color. Multi-color for single character (each pixel a different color) is not supported.
The 7650 controller (LPC2106) offers optional cursor support.
Pictures can be displayed if they are delivered in an appropriate format. There is a converter which translates a picture in a fitting format (C-style), which can be integrated in the SW or transfered to the controller via the external connection.
The connection to the host can either be RS232, RS232-TTL, I2C or SPI. Both last mentioned connections are not implemented yet.
There is an own instruction set for communication between the LCD-Controller and the host. Several graphic functions (draw lines, draw rectangular, circles etc) are already implemented. A PC tool is available which allows to test all available functions via a RS232 connection.
For home brew applications often some keys are needed. The current SW supports the existing rocker as well as 8 additional keys.
176 * 208 pixel , 4096 colors (12 bit) Connectivity RS232 , RS232(TTL), I2C,SPI Keys, Rocker LCD rocker is supported, as well as additional keys Character set 3 fixed, 1 loadable, GLCD FontCreater2 compatible Direction Upright and landscape (rocker right hand)
Character fixed size, float size, transparent w/o background color, w/ back ground color Cursor Optional cursor support. Graphic lines, rectangular, circles , round corners, fill Picture Tool available for converting BMP to RGB (C style) ***
Update rate around 23 ms , independent on instruction Test tool PC (Visual Basic) test tool PC7650 available ISP Tool ISP tool by Philips Protocol Protocol documentation available soon Voltage 5V, 60 mA ( max 110 mA , depending on back light intensity)
story about the design and
the development can
be read here. (in German only)
Schematics of the Controller ( around 460KByte)
(click to the pictures)