119 lines
3.1 KiB
Markdown
119 lines
3.1 KiB
Markdown
# OLED SSD1306 Linux driver
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This is plain c code using linux I2C device node (/dev/i2c-X X for 0,1,2,3...).
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Please make sure the linux has run "modprobe i2c-dev".
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128x64 and 128x32 are supporting and using I2C interface ONLY
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## Files
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**linux_i2c.c** source code for i2c control in linux device node.
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**linux_i2c.h** header file for i2c control in linux.
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**ssd1306.c** i2c protocol functions to control oled SSD1306.
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**ssd1306.h** header file for i2c protocol functions and defined commands in SSD1306.
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**font.h** font header file define 5x7 small font and 8x8 normal font. ascii value from 0x20(SPACE) to 0x7e(~).
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**main.c** main file to take params and control oled SSD1306.
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**Makefile** plain Makefile to build the source code. It works in raspberry pi.
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**Readme.md** this readme file.
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## How to compile
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Require make and gcc. If you use cross compile, please self define $(CC).
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Type "make" to build binary "ssd1306_bin".
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Type "make clean" to clean the project.
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## How to use
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- always init oled module ONCE when power up.
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- set the device node address EVERYTIME if not using default value /dev/i2c-0
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- the init oled module always reset XY cursor to (0,0)
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- all params can set together
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- clear screen if new text need to write, otherwise wording overlapping happened
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- resolution value stored in /tmp/.ssd1306_oled_type with format like "128x64" or "128x32" or "64x48"
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- always do display rotation first and then filling text. otherwise the text cause mirror
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- make sure the XY cursor setting in correct location before printing text
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### Params
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```sh
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-I init oled (128x32 or 128x64 or 64x48)
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-c clear (line number or all)
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-d 0/display off 1/display on
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-f 0/small font 5x7 1/normal font 8x8 (default small font)
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-h help message
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-i 0/normal oled 1/invert oled
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-l put your line to display
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-m put your strings to oled
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-n I2C device node address (0,1,2..., default 0)
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-r 0/normal 180/rotate
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-x x position
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-y y position
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```
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## Example
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### init the OLED once
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- resolution 128x64
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```sh
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$ ./ssd1306_bin -I 128x64
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```
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- resolution 128x32
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```sh
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$ ./ssd1306_bin -I 128x32
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```
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- resolution 64x48
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```sh
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$ ./ssd1306_bin -I 64x48
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```
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### clear display
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- clear 1st line
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```sh
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./ssd1306_bin -c0
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```
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- clear 2nd line
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```sh
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$ ./ssd1306_bin -c1
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```
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- clear 4th line
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```sh
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$ ./ssd1306_bin -c3
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```
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- clear whole screen
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```sh
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$ ./ssd1306_bin -c
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```
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### display on/off
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- turn off display
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```sh
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$ ./ssd1306_bin -d 0
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```
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- turn on display
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```sh
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$ ./ssd1306_bin -d 1
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```
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### inverting display
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- normal oled (0 is off, 1 is on)
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```sh
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$ ./ssd1306_bin -i 0
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```
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- invert oled (0 is on, 1 is off)
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```sh
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$ ./ssd1306_bin -i 1
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```
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### print words
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- write line "Hello World"
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```sh
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$ ./ssd1306_bin -l "Hello World"
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```
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- write message "alpha\nbravo\ncharlie\ndelta" (please place \n for next line)
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```sh
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$ ./ssd1306_bin -m "alpha\nbravo\ncharlie\ndelta"
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```
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### I2C device address (default is /dev/i2c-0)
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- using /dev/i2c-1
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```sh
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$ ./ssd1306_bin -n 1
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```
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### rotate display
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- normal orientation
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```sh
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$ ./ssd1306_bin -r 0
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```
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- turn 180 orientation
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```sh
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$ ./ssd1306_bin -r 180
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```
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### set cursor location
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- set XY cursor 8,1(x is column, 8 columns skipping, y is row, 2nd line)
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```sh
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$ ./ssd1306_bin -x 8 -y 1
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```
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