16
DIO & GPS PPS Port
Initialization
sudo -s
echo 446 > /sys/class/gpio/export # SOM_GPO0
echo out > /sys/class/gpio/gpio446/direction
echo 0 > /sys/class/gpio/gpio446/value
echo 447 > /sys/class/gpio/export # SOM_GPO1
echo out > /sys/class/gpio/gpio447/direction
echo 0 > /sys/class/gpio/gpio447/value
echo 448 > /sys/class/gpio/export # SOM_GPO2
echo out > /sys/class/gpio/gpio448/direction
echo 0 > /sys/class/gpio/gpio448/value
echo 445 > /sys/class/gpio/export # SOM_GPO3
echo out > /sys/class/gpio/gpio445/direction
echo 0 > /sys/class/gpio/gpio445/value
echo 443 > /sys/class/gpio/export # SOM_GPI1
echo in > /sys/class/gpio/gpio443/direction
echo 444 > /sys/class/gpio/export # SOM_GPI2
echo in > /sys/class/gpio/gpio444/direction
echo 441 > /sys/class/gpio/export # SOM_GPI3
echo in > /sys/class/gpio/gpio441/direction
IEEE 802.3at Power over Ethernet Port
17
The DO is followed by open-drain design, i.e., the output voltage
is decided by the external power source.
W
e recommend to
design the external power source between 5V to 24V. The DI
treat 0 to 1.5V voltage input as 0, and treat 5 to 40V voltage input
as 1. In Linux, each GPIO is mapped to a virtual folder. And the
PPS0 is defined in our official device tree. Please refer to the
following table for information on wiring and programming the
isolated DIO channels.
DIO & GPS PPS Pin Definition
The Gigabit PoE ++ port supply power and data on a standard CAT-5 or
better Ethernet cable. Acting as a PSE (Power Sourcing Equipment),
compliant with IEEE 802.3bt, it has a total power budget of 144W while
each port can deliver up to 90W to a Powered Device (PD). PoE
automatically detects and determine if the connected device is PoE PD
or not before supplying power, making it compatible with standard
Ethernet devices as well. There are screw-lock holes (indicated in
)
for each port to ensure cables are tightly secured.
red
Set DO Value
The following example takes DO0 as an example. The GPIO
number for DO0 is
446
sudo -s
# Set DO0 to 0
echo 446 > /sys/class/gpio/export # SOM_GPO0
echo out > /sys/class/gpio/gpio446/direction
echo 0 > /sys/class/gpio/gpio446/value
# Set DO0 to 1
echo 446 > /sys/class/gpio/export # SOM_GPO0
echo out > /sys/class/gpio/gpio446/direction
echo 1 > /sys/class/gpio/gpio446/value
Read DI Value
The following example takes DI3 as an example. The GPIO
number of DI3 is
441
cat /sys/class/gpio/gpio441/value
Grounding Point
18
The
system offers EMI protection with an isolated PCB design. If you are
powering the NRU-52S using an isolated power supply, please make
sure the chassis grounding point is connected.
