libssd1306

We have written blog posts documenting how to use this library here: https://stealthy.io/blog/tag/libssd1306/index.html.

INTRODUCTION

This is a C library to be used for displaying on the SSD1306 OLED display such as those sold by Adafruit, Sparkfun and others, and whose data sheet can be found here and here.

If your goal is to use Arduino or CircuitPython, this library is not for you.

This library is for the special use case where you have an application running on the Raspberry Pi, Beaglebone Black or any other Linux single board computer (SBC) with I²C pins available to connect this OLED screen to.

The library provides both the I²C user-land device driver and the graphics primitives for the developer to be able to perform display tasks using a single library.

Sometimes you want to integrate writing to this display into a larger code base which is not written in Python but needs to run on such devices.

This is why this library is in C, so it can directly execute on the Raspberry Pi or similar SBCs where it can be integrated into other applications easily.

Another reason for using this C library is to be able to integrate this display with libraries like libev or similar event-based libraries, and control the display using events and keeping the power consumption low on such devices.

For Unicode support, the user must install libunistring-dev.

BUILD and TEST

PRE-REQUISITES

Install Pre-requisties first.

$ sudo apt-get -y install libfreetype6-dev fonts-freefont-ttf ttf-bitstream-vera \
        autoconf automake libtool autotools-dev build-essential pkg-config
### optional pre-requisites
$ sudo apt-get -y install libev-dev libunistring-dev

You may install several other font libraries such as Microsoft fonts which we support.

### optional Microsoft Fonts installer, if you want it
$ sudo apt-get -y install ttf-mscorefonts-installer

COMPILE

$ ./autogen.sh
$ ./configure
$ make

If you want to install this library in a location other than /usr/local you want to run configure with the --prefix option.

If you want to build in debug mode, you want to run configure with the --enable-debug option.

The configure script auto-detects the presence of libev and turns on compilation of examples that use libev. If you want to disable this you may use the --without-libev option with the configure script.

For example, here is how you would run the configure script with all the above optional library options.

$ ./configure --enable-debug --prefix=$HOME/local

TEST

We have provided some sample applications to test the framebuffer objects, the I²C I/O, and to use libev along with this library to demonstrate writing to the SSD1306 OLED screen using an event library.

###  if you want to run all the tests on the attached OLED device on a Raspberry Pi
$ make check

### if you want to check graphics framebuffer code without any device connected
$ ./examples/test_fb_graphics

### if you just want to run a single test on a connected SSD1306 I<sup>2</sup>C device  manually
$ ./examples/test_i2c_128x32

### if you want to run the clock display for 30 seconds
$ ./examples/test_libev_clock

DEBUGGING

To load the example executables directly into the debugger like gdb or a memory profiler like valgrind, you must use the libtool script created during the build process. It will locate all the required libraries, set the environment correctly and will run the program under the debugger. For example,

### check the libraries that are linked
$ ./libtool --mode=execute ldd -d -r ./examples/test_libev_clock

### running executable under gdb
$ ./libtool --mode=execute gdb --args ./examples/test_draw_line

### running executable under valgrind
$ ./libtool --mode=execute valgrind --tool=memcheck ./examples/test_fb_graphics

stealthylabs / libssd1306

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