.TH hal_bb_gpio "9" "" "LinuxCNC Documentation" "HAL Component"
.SH NAME

hal_bb_gpio \- Driver for beaglebone GPIO pins

.SH SYNOPSIS
.HP
.B loadrt hal_bb_gpio \fIuser_leds=#,...\fR \fIinput_pins=#,...\fR \fIoutput_pins=#,...\fB

.SH USER LEDS
The \fIuser_leds\fR loadrt parameter controls which LEDs are available to HAL.
Valid range: 0..3.  These LEDs are next to the ethernet jack and the LinuxCNC
numbers match the silkscreen on beaglbone black.  Empirically, these seem to be
OR'd with whatever function is assigned to the LED in Linux.

.SS PINS
.TP
\fBbb_gpio.userled\fIN\fR bit in
.TQ
\fBbb_gpio.userled\fIN\fB-invert\fR bit in
The associated LED is lit if \fBuserled\fIN\fR xor \fBuserled\fIN\fR-invert\fB
is TRUE.

.SH INPUT PINS
The \fIinput_pins\fR loadrt parameter controls which physical I/O pins are
available to HAL as input pins.  The numbering is "800+N" for pin N on
connector P8, and "900+N" for pin N on connector P9.  For example, "803"
means connector P8 pin 3, which is also described in BeagleBone documentation
as "gpmc_ad6".

Specifying pins that are otherwise in use by the system may have undesirable
side effects, such as crashing rtapi_app or the whole system.

.SS PINS
.TP
\fBbb_gpio.p\fIN\fB.in-\fINN\fR bit out
.TQ
\fBbb_gpio.p\fIN\fB.in-\fINN\fB-invert\fR bit in
\fBin-\fINN\fR is a snapshot of the value of the corresponding physical pin XOR
the value of the corresponding \fBin-\fINN\fB-invert\fR pin.

.SH OUTPUT PINS
The \fIinput_pins\fR loadrt parameter controls which physical I/O pins are
available to HAL as input pins.  The numbering is "800+N" for pin N on
connector P8, and "900+N" for pin N on connector P9.

Specifying pins that are otherwise in use by the system may have undesirable
side effects, such as crashing rtapi_app or the whole system.

.SS PINS
.TP
\fBbb_gpio.p\fIN\fB.out-\fINN\fR bit out
.TQ
\fBbb_gpio.p\fIN\fB.out-\fINN\fB-invert\fR bit in
The corresponding physical pin is driven with the result of
\fBin-\fINN\fR xor \fBin-\fINN\fB-invert\fR.

.SH PARAMETERS
None

.SH FUNCTIONS
.TP
.B bb_gpio.read
Update HAL pins from physical pins.
.TP
.B bb_gpio.write
Update physical pins from HAL pins.

.SH LICENSE
GPL