Difference between revisions of "Raspberry Pi LCD program"
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== Download == |
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download the program source from http://www.bitwizard.nl/software/bw_lcd.c |
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You will need a kernel with spidev enabled and the raspberry pi SPI driver included. See [[Raspberry pi spi kernel]] |
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This program works well with the rpi_serial board http://www.bitwizard.nl/catalog/product_info.php?cPath=25&products_id=69 and the spi_lcd board: http://www.bitwizard.nl/catalog/product_info.php?products_id=89 . |
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== Command line arguments == |
== Command line arguments == |
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-d <delay> delay between bytes. default: 15 us. |
-d <delay> delay between bytes. default: 15 us. |
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LCD options: |
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-a <addr> address of display, defaults to 0x82 |
-a <addr> address of display, defaults to 0x82 |
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-p <c>,<l> Jump to line <l> and character <c> |
-p <c>,<l> Jump to line <l> and character <c> |
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-C clearscreen |
-C clearscreen |
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-f <file> display text from file (not implemented yet). |
-f <file> display text from file (not implemented yet). |
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general bw SPI options: |
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-r <reg> |
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-v <val> set register to value. Requires -r. |
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== Example commands == |
== Example commands == |
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Print current date on line 0: |
Print current date on line 0: |
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bw_lcd -p 0,0 -t `date +%m/%d/%Y` |
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Print the text "Hello World" on line 1, character 2: |
Print the text "Hello World" on line 1, character 2: |
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bw_lcd -T 2,1 "Hello World" |
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Print the contents of "textfile": |
Print the contents of "textfile": |
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bw_lcd -f textfile |
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Write two different strings to two daisy-chained displays: |
Write two different strings to two daisy-chained displays: |
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bw_lcd -a 82 -T 0,0 display0 |
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bw_lcd -a 84 -T 0,0 display1 |
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My Pi runs the following script every minute: |
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#! /bin/sh |
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./bw_lcd -a 80 -C |
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./bw_lcd -a 82 -C |
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./bw_lcd -a 80 -T 0,0 'My wlan0 IP is' |
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./bw_lcd -a 80 -T 0,1 `/sbin/ifconfig wlan0 | sed '/inet\ /!d;s/.*r://g;s/\ .*//g'` |
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./bw_lcd -a 82 -T 0,0 'My eth0 IP is' |
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./bw_lcd -a 82 -T 0,1 `/sbin/ifconfig eth0 | sed '/inet\ /!d;s/.*r://g;s/\ .*//g'` |
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This prints the IP addresses of both network interfaces on my two displays. |
Latest revision as of 11:45, 11 November 2015
Download
download the program source from http://www.bitwizard.nl/software/bw_lcd.c
You will need a kernel with spidev enabled and the raspberry pi SPI driver included. See Raspberry pi spi kernel
This program works well with the rpi_serial board http://www.bitwizard.nl/catalog/product_info.php?cPath=25&products_id=69 and the spi_lcd board: http://www.bitwizard.nl/catalog/product_info.php?products_id=89 .
Command line arguments
SPI options: -D <device> SPI device to use. default: /dev/spidev0.0 -s <speed> speed to use on the SPI bus default 0.5MHz. -d <delay> delay between bytes. default: 15 us.
LCD options: -a <addr> address of display, defaults to 0x82 -p <c>,<l> Jump to line <l> and character <c> -t <text> print text -T <c>,<l> <text> Print tekst starting at line <l> character <c>. -b < b > Adjust backlight level -c <c> Adjust contrast -C clearscreen -f <file> display text from file (not implemented yet).
general bw SPI options: -r <reg> -v <val> set register to value. Requires -r.
Example commands
Print current date on line 0:
bw_lcd -p 0,0 -t `date +%m/%d/%Y`
Print the text "Hello World" on line 1, character 2:
bw_lcd -T 2,1 "Hello World"
Print the contents of "textfile":
bw_lcd -f textfile
Write two different strings to two daisy-chained displays:
bw_lcd -a 82 -T 0,0 display0 bw_lcd -a 84 -T 0,0 display1
My Pi runs the following script every minute:
#! /bin/sh ./bw_lcd -a 80 -C ./bw_lcd -a 82 -C ./bw_lcd -a 80 -T 0,0 'My wlan0 IP is' ./bw_lcd -a 80 -T 0,1 `/sbin/ifconfig wlan0 | sed '/inet\ /!d;s/.*r://g;s/\ .*//g'` ./bw_lcd -a 82 -T 0,0 'My eth0 IP is' ./bw_lcd -a 82 -T 0,1 `/sbin/ifconfig eth0 | sed '/inet\ /!d;s/.*r://g;s/\ .*//g'`
This prints the IP addresses of both network interfaces on my two displays.