PCF8833 LCD python bindings for the Raspberry Pi

Schematics & python module to drive a PCF8833 LCD [as used on Nokia 6100]
This project is intended to help who wants to create a cheap prototype setup to interface an LCD controlled by the Philips PCF8833 chip.

Specification: LCD controller Philips PFC8833 Interface SPI Serial connection Pixel resolution 132x132 pixels Color resolution 12 bits (4096 colors) Visible area 3cm x 3cm Operating voltage 3.3V

Further technical details for the LCD screen can be found in the datasheet [PDF].

Pre-requisites

Compile and install the wiringPi python bindings from https://github.com/rm-hull/wiringPi.

Next, install PIL (Python Imaging Library) as follows:

$ sudo apt-get install zlibc libjpeg-dev libpng3 libfreetype6 libfreetype6-dev python-pip
$ sudo pip install pillow

Building and installing the software

After having cloned from github:

$ python setup.py clean build
$ sudo python setup.py install

This should install the files in your local dist-files area (somewhere like /usr/local/lib/python2.7/distfiles/pcf8833).

Next, test at the hardware and software is working:

$ cd examples
$ sudo ./loadImage.py

Wiring schematic

Pin Function Pin Function 1 VDD 3,3V 6 VLCD 3,3V 2 /Reset 7 NC 3 SDATA 8 GND 4 SCLK 9 LED- 5 /CS 10 LED+ (6V)

The LCD backlight leds need to be driven from a different power source arrount 7V or needs a booster DC/DC converter. This implementation uses a separate power source of 8V and a potentiometer of 470 hom so that backlight can be tuned to perfect bright intensity. The Raspberry Pi can also be powered from the GPIO connector as shown here.

Cheap Prototype

This can be tested with an old or broken NOKIA 6100 with a working LCD. Because it's hard to connect to the LCD directly because of the very small LCD connector, one can use the phone's PCB to easily connect wires to the LCD as the LCD pins are mapped in the cooper connection under the LCD as shown in the image:

##And here it is working!

References

• https://projects.drogon.net/raspberry-pi/wiringpi/pins/

• https://github.com/rm-hull/pcd8544

• https://github.com/rm-hull/wiringPi