-.TH "GPIO" "21st October 2012" "Command-Line access to Raspberry Pi and PiFace GPIO"
+.TH "GPIO" "March 2013" "Command-Line access to Raspberry Pi's GPIO"
.SH NAME
-gpio \- Command-line access to Raspberry Pi and PiFace GPIO
+gpio \- Command-line access to Raspberry Pi's GPIO
.SH SYNOPSIS
.B gpio
.B \-v
.PP
.B gpio
-.B [ \-g ]
-.B read/write/wb/pwm/mode ...
+.B [ \-g | \-1 ]
+.B mode/read/write/aread/awrite/wb/pwm/clock ...
+.PP
+.B gpio
+.B [ \-x extension:params ]
+.B mode/read/write/aread/awrite/pwm ...
.PP
.B gpio
.B [ \-p ]
.B ...
.PP
.B gpio
-.B readall
+.B readall/reset
.PP
.B gpio
.B unexportall/exports
.B ...
.PP
.B gpio
+.B wfi
+.B ...
+.PP
+.B gpio
.B drive
group value
.PP
range
.PP
.B gpio
-.B load \ i2c/spi
+.B load \ i2c/spi ...
.PP
.B gpio
.B gbr
diagnostic purposes, but can be used in shell scripts for general if
somewhat slow control of the GPIO pins.
+It can also control the IO's on the PiFace IO board and load the SPI and I2C
+kernel modules if required.
+
Additionally, it can be used to set the exports in the \fI/sys/class/gpio\fR
system directory to allow subsequent programs to use the \fR/sys/class/gpio\fR
interface without needing to be run as root.
.TP
.B \-g
Use the BCM_GPIO pins numbers rather than wiringPi pin numbers.
+\fINote:\fR The BCM_GPIO pin numbers are always used with the
+export and edge commands.
+
+.TP
+.B \-1
+Use the physical pin numbers rather than wiringPi pin numbers.
+\fINote:\fR that this applies to the P1 connector only. It is not possible to
+use pins on the Revision 2 P5 connector this way, and as with \-g the
+BCM_GPIO pin numbers are always used with the export and edge commands.
+
+.TP
+.B \-x extension
+This causes the named extension to be initialised. Extensions
+comprise of a name (e.g. mcp23017) followed by a colon, then the
+pin-base, then more optional parameters depending on the extension type.
+See the web page on http://wiringpi.com/the-gpio-utility/
.TP
.B \-p
-Use the PiFace interface board and its corresponding pin numbers.
+Use the PiFace interface board and its corresponding pin numbers. The PiFace
+will always appear at pin number 200 in the gpio command. You can assign any
+pin numbers you like in your own programs though.
.TP
.B read <pin>
if the pin is in input mode, or the last value written if the pin is in output
mode.
+.TP
+.B reset
+Resets the GPIO - As much as it's possible to do. All pins are set to input
+mode and all the internal pull-up/down resistors are disconnected (tristate mode).
+
.TP
.B pwm <pin> <value>
-Write a PWM value (0-1023) to the given pin.
+Write a PWM value (0-1023) to the given pin. The pin needs to be put
+into PWM mode first.
+
+.TP
+.B clock <pin> <frequency>
+Set the output frequency on the given pin. The pin needs to be put into
+clock mode first.
.TP
.B mode <pin> <mode>
.B unexport
Un-Export a GPIO pin in the /sys/class/gpio directory.
+.TP
+.B wfi <pin> <mode>
+This set the given pin to the supplied interrupt mode: rising, falling
+or both then waits for the interrupt to happen. It's a non-busy wait,
+so does not consume and CPU while it's waiting.
+
.TP
.B drive
group value
Change the PWM range register. The default is 1024.
.TP
-.B load i2c/spi
-This loads the i2c or the spi drivers into the system and changes the permissions on
-the associated /dev/ entries so that the current user has access to them.
+.B load i2c [baudrate]
+This loads the i2c or drivers into the kernel and changes the permissions
+on the associated /dev/ entries so that the current user has access to
+them. Optionally it will set the I2C baudrate to that supplied (or as
+close as the Pi can manage) The default speed is 100Kb/sec.
+
+.TP
+.B load spi [buffer size in KB]
+This loads the spi drivers into the kernel and changes the permissions
+on the associated /dev/ entries so that the current user has access to
+them. Optionally it will set the SPI buffer size to that supplied. The
+default is 4KB.
.TP
.B gbr
The board jumpers need to be in-place to do this operation.
-.SH "WiringPi vs. GPIO Pin numbering"
+.SH "WiringPi vs. BCM_GPIO Pin numbering"
.PP
.TS
-r r r l.
-WiringPi GPIO-r1 GPIO-r2 Function
+c c c c l.
+WiringPi GPIO-r1 GPIO-r2 P1-Phys Function
_
-0 17 17
-1 18 18 (PWM)
-2 21 27
-3 22 22
-4 23 23
-5 24 24
-6 25 25
-7 4 4
-8 0 2 I2C: SDA0
-9 1 3 I2C: SCL0
-10 8 8 SPI: CE0
-11 7 7 SPI: CE1
-12 10 10 SPI: MOSI
-13 9 9 SPI: MISO
-14 11 11 SPI: SCLK
-15 14 14 TxD
-16 15 16 RxD
+ 0 17 17 11
+ 1 18 18 12 (PWM)
+ 2 21 27 13
+ 3 22 22 15
+ 4 23 23 16
+ 5 24 24 18
+ 6 25 25 22
+ 7 4 4 7
+ 8 0 2 3 I2C: SDA0
+ 9 1 3 5 I2C: SCL0
+10 8 8 24 SPI: CE0
+11 7 7 26 SPI: CE1
+12 10 10 19 SPI: MOSI
+13 9 9 21 SPI: MISO
+14 11 11 23 SPI: SCLK
+15 14 14 8 TxD
+16 15 16 10 RxD
17 - 28
18 - 29
19 - 30
20 - 31
.TE
+Note that "r1" and "r2" above refers to the board revision. Normally
+wiringPi detects the correct board revision with use for it's own
+numbering scheme, but if you are using a Revision 2 board with some
+of the pins which change numbers between revisions you will need
+to alter your software.
+
.SH FILES
.TP 2.2i
.LP
WiringPi's home page
.IP
-https://projects.drogon.net/raspberry-pi/wiringpi/
+http://wiringpi.com/
.SH AUTHOR
.SH COPYRIGHT
-Copyright (c) 2012 Gordon Henderson
+Copyright (c) 2012-2013 Gordon Henderson
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
.SH TRADEMARKS AND ACKNOWLEDGEMENTS
-Raspberry Pi is a trademark of the Raspberry Pi Foundation.
+Raspberry Pi is a trademark of the Raspberry Pi Foundation. See
+http://raspberrypi.org/ for full details.
~ianmdlvl / wiringPi.git / blobdiff