Documentation and Python library module for interfacing a PCD8544 LCD screen to a Rasbperry Pi. Cheap Nokia 5110 modules can be picked up on ebay with a breakout board for a few pounds.
Further technical details for the LCD screen can be found in the datasheet [PDF].
Compile and install the wiringPi python bindings from https://github.com/rm-hull/wiringPi. Make sure you install both python-dev and libi2c-dev. This library specifically requires the python binding baked into this software, which have not been pushed back to drogon.
Next, install PIL (Python Imaging Library) as follows:
$ sudo apt-get install zlibc libpng3 libfreetype6 libfreetype6-dev python-pip
$ sudo pip install pillow
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 ares (somewhere
like /usr/local/lib/python2.7/distfiles/pcd8544
).
Next, test at the hardware and software is working:
$ cd examples
$ sudo ./alphabet_text.py
Most of the ASCII character set should be displayed. There are a few other examples of graphics rendering in the same directory.
There appears to be different pin-out configurations on PCD8544 modules - beware!
Although the python library (currently) used software-base bit-banging to do the SPI chattering, the pins chosen should be compatible with hardware SPI. The above diagram was modified for my wiring setup from an SVG from http://shiro.be/ - all rights of the original author reserved.
With 4 push-buttons, resistor values 10K.
Buttons (from top to bottom) are wired onto BCM pins as follows:
- GPIO 14 (TxD)
- GPIO 17
- GPIO 25
- GPIO 22
The finished article, and a video:
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Documentation
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More examples
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Introduce small/tiny font handling onto drawable PIL surfaces
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Implement module for scanning push buttons
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Hardware SPI rather than software emulation
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http://elinux.org/Rpi_Low-level_peripherals#General_Purpose_Input.2FOutput_.28GPIO.29
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http://binerry.de/post/25787954149/pcd8544-library-for-raspberry-pi
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http://www.avdweb.nl/arduino/hardware-interfacing/nokia-5110-lcd.html
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http://www.raspberrypi.org/phpBB3/viewtopic.php?f=32&t=9814&start=100
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http://www.henningkarlsen.com/electronics/t_imageconverter_mono.php