Robotics J601 carrier board Hardware Interfaces Usage

The reComputer Robotics J601 is a high-performance robotics carrier board designed for the NVIDIA Jetson AGX Thor module, targeting advanced embodied AI and robotic control applications. Equipped with extensive connectivity options — including high-speed Ethernet, M.2 slots for 5G and Wi-Fi/BT modules, USB 3.2 ports, 4x CAN (with CAN FD support), RS-232/485, I2C, I2S, UART, GMSL2 expansion (up to 8 cameras), and wide-range DC input — it serves as a powerful robotic brain capable of processing complex data from various sensors.

Supporting frameworks like NVIDIA Isaac ROS, Hugging Face, PyTorch, and ROS 2/1, the reComputer Robotics J601 bridges large language model-driven decision-making with physical robotics control, such as motion planning and sensor fusion. Ideal for the rapid development of autonomous robots, it accelerates time-to-market with ready-to-use interfaces and optimized AI frameworks.

Interfaces Usage

The following will introduce the various interfaces of the Robotics J601 board and how to use them.

USB

The Robotics J601 carrier board is equipped with multiple USB ports, including USB 3.2 Type-A ports (Host) for high-speed peripheral connectivity, one USB 3.0 Type-C port for flashing, and one USB 2.0 Type-C port for device mode/debugging.

USB 3.2 Speed Test

Plug in a USB 3.0 flash drive and test its read/write speed. Note that actual speeds depend on the USB drive's own performance.

Create a test script:

vim test_usb_speed.sh

Paste the following content:

#!/bin/bash

echo "seeed" | sudo -S dd if=/dev/zero of=/dev/sda bs=1000M count=2 conv=fdatasync
sleep 1
sudo sh -c "sync && echo 3 > /proc/sys/vm/drop_caches"
sleep 1
echo "seeed" | sudo -S dd if=/dev/sda of=/dev/null bs=1000M count=2

info

Replace /dev/sda with the actual device name of your USB drive. You can use lsblk to check.

Make the script executable and run it:

chmod +x test_usb_speed.sh
./test_usb_speed.sh

USB 2.0 Type-C Debug Port

Using this serial port, via the USB-C data cable, you can monitor the debugging information of input and output on the PC side.

Windows

Step 1. Connect the J601 to the PC via a USB-C data cable.

Step2. Downloaded the CP210X Driver on your PC.

Step3. Connect the PC via a USB data cable, extract the downloaded file and install driver on your PC.

Step4. Open Open the Device Manager on your Windows PC and check the COM port number assigned to the reComputer Super. It should appear under "Ports (COM & LPT)" as "Silicon Labs CP210x USB to UART Bridge (COMX)", where X is the COM port number.

Step5. Open the serial port tool(Here, we use the MobaXterm tool as an example), create a new session.

Step6. Select the Serial tool.

Step7. Select corresponding serial port, set the baud rate to 115200 and click "OK".

Step8. Login your reComputer Super with the username and password.

Linux

Step 1. Connect the J601 to the Linux PC via a USB-C data cable.

Step 2. Find the serial device:

ls /dev/ttyUSB*

Step 3. Connect to the serial console:

screen /dev/ttyUSB0 -b 115200

You should now see the J601 serial console output and can log in with your username and password.

GMSL

The Robotics J601 features a GMSL camera expansion header that supports up to 8 GMSL cameras simultaneously, enabling multi-camera robotic vision applications.

Supported GMSL Camera Models

SG3S-ISX031C-GMSL2F
SG2-AR0233C-5200-G2A
SG2-IMX390C-5200-G2A
SG8S-AR0820C-5300-G2A
Orbbec Gemini 335Lg

Hardware Connection

Connect the GMSL expansion board to the camera expansion header on the J601 carrier board, then connect your GMSL cameras to the expansion board.

Usage Instruction

note

Before enabling the GMSL functionality, please ensure that you have installed a JetPack version with the GMSL expansion board driver.

Step 1. Install the video interface configuration tools:

sudo apt update
sudo apt install v4l-utils wmctrl
#example
media-ctl -d /dev/media0 --set-v4l2 '"ser_0_ch_0":1[fmt:YUYV8_1X16/1920x1080]'
media-ctl -d /dev/media0 --set-v4l2 '"des_0_ch_0":0[fmt:YUYV8_1X16/1920x1080]'

v4l2-ctl -d /dev/video0 -c sensor_mode=1

rm -f /tmp/gmsl0.yuyv; mkfifo /tmp/gmsl0.yuyv

v4l2-ctl -d /dev/video0 --stream-mmap=2 --stream-to=/tmp/gmsl0.yuyv >/tmp/gmsl0_v4l2.log 2>&1 &
gst-launch-1.0 -q filesrc location=/tmp/gmsl0.yuyv do-timestamp=true blocksize=4147200 ! rawvideoparse format=yuy2 width=1920 height=1080 framerate=30/1 ! queue max-size-buffers=1 max-size-bytes=0 max-size-time=0 leaky=downstream ! videoconvert ! videoscale method=0 ! video/x-raw,width=892,height=489 ! xvimagesink sync=false async=false max-lateness=0 qos=false force-aspect-ratio=true

Use the Camera of Gemini 335Lg

# Download the Orbbec Gemini 335Lg visualization tool
wget https://github.com/orbbec/OrbbecSDK_v2/releases/download/v2.4.8/OrbbecViewer_v2.4.8_202507031357_a1355db_linux_aarch64.zip
# Unzip and run the UI tool
unzip OrbbecViewer_v2.4.8_202507031357_a1355db_linux_aarch64.zip
cd OrbbecViewer_v2.4.8_202507031357_a1355db_linux_aarch64
./OrbbecViewer

The first time you turn it on, you might need to update the firmware. Opening the data stream, you can view the video from the camera.

I2S

The Robotics J601 provides an I2S audio interface with amplifier output and microphone input for audio playback and recording.

Hardware Connection

Usage Instruction

Step 1. Configure the I2S2 audio mux and test tone output:

# Configure I2S2 mux
amixer -c 2 sset "I2S2 Mux" "ADMAIF1"

# Play a 440Hz sine wave test tone (one iteration)
speaker-test -D hw:2,0 -c 2 -r 48000 -t sine -f 440 -l 1

info

The -l 1 flag means the test tone will play only once and then stop.

Step 2. Play your own audio file:

aplay -D hw:2,0 -c 2 -r 48000 your_audio_file.wav

note

Replace your_audio_file.wav with the path to your actual audio file. Ensure the audio file format matches the specified sample rate (48000 Hz) and channel count (2).

UART

The Robotics J601 provides a UART interface via a standard JST header for serial communication with external devices.

Hardware Connection

For UART communication, connect the USB-to-TTL tool according to the following wiring:

TX → RX
RX → TX
GND → GND

Usage Instruction

Connect the USB-to-TTL tool to the Robotics J601 UART port and the PC, then open the serial port tool on the PC side and set the baud rate to 115200.

You can use a simple Python script for serial communication testing:

import serial
import time

ser = serial.Serial('/dev/ttyTHS1', 115200, timeout=1)
ser.write(b'Hello Jetson!\n')
while True:
    if ser.in_waiting:
        data = ser.readline()
        print("get:", data.decode('utf-8').strip())
    time.sleep(0.1)

ser.close()

Run the script on the Jetson device:

python3 uart_test.py

RGB

test_rgb.sh

#!/bin/bash

# ==============================================================================
# Script Name: test_rgb.sh
# Target Platform: Seeed reComputer J601 (Jetson)
# Description: Automatically tests RGB LEDs by lighting up Red, Green, Blue, 
#              and White colors sequentially for 1 second each.
# Usage: sudo ./test_rgb.sh
# ==============================================================================

# Define LED paths
LED_DIR="/sys/class/leds"
RED="$LED_DIR/red/brightness"
GREEN="$LED_DIR/green/brightness"
BLUE="$LED_DIR/blue/brightness"

# Check if running as root (sysfs write access requires root privileges)
if [ "$EUID" -ne 0 ]; then
    echo "Error: Please run this script with sudo!"
    echo "Example: sudo $0"
    exit 1
fi

# Check if the hardware paths exist
if [ ! -d "$LED_DIR/red" ] || [ ! -d "$LED_DIR/green" ] || [ ! -d "$LED_DIR/blue" ]; then
    echo "Error: RGB LED hardware paths not found. Please check your driver or device model."
    exit 1
fi

# Helper function: Control LED states
# Arguments: set_leds <Red(0/1)> <Green(0/1)> <Blue(0/1)>
set_leds() {
    echo "$1" > "$RED"
    echo "$2" > "$GREEN"
    echo "$3" > "$BLUE"
}

echo "========================================"
echo "         Starting Jetson RGB LED Test    "
echo "========================================"

# 1. Initialization: Turn off all LEDs
echo "-> Initializing: Turning off all LEDs"
set_leds 0 0 0
sleep 0.5

# 2. Red LED on for 1 second
echo "-> [ON] Red Light"
set_leds 1 0 0
sleep 1

# 3. Green LED on for 1 second
echo "-> [ON] Green Light"
set_leds 0 1 0
sleep 1

# 4. Blue LED on for 1 second
echo "-> [ON] Blue Light"
set_leds 0 0 1
sleep 1

# 5. Mixed White LED on for 1 second (Red + Green + Blue mixed)
echo "-> [ON] White Light (RGB Mixed)"
set_leds 1 1 1
sleep 1

# 6. Test completed, turn off all LEDs
echo "-> Test completed: Turning off all LEDs"
set_leds 0 0 0

echo "========================================"
echo "             LED Test Ended             "
echo "========================================"

sudo chmod +x test_rgb.sh
sudo ./test_rgb.sh

I2C

The Robotics J601 provides I2C interfaces through standard JST headers, enabling easy connection of sensors and peripherals for system expansion.

Hardware Connection

Connect your I2C device to the I2C interface on the carrier board:

Power → Power
SDA → SDA
SCL → SCL
Ground → Ground

Usage Instruction

Step 1. Install the I2C testing tools:

sudo apt update
sudo apt-get install i2c-tools

Step 2. View the I2C bus mappings:

i2cdetect -l

Step 3. Scan for devices on the I2C bus:

sudo i2cdetect -y -r 1

Step 4. Read a register from an I2C device. For example, to read register 0x00 from a device at address 0x58 on bus i2c-1:

sudo i2cget -y 1 0x58 0x00

CAN

CAN (Controller Area Network) is a robust vehicle bus standard that enables microcontrollers and devices to communicate with each other without a host computer. The Robotics J601 provides 4 CAN interfaces (CAN0, CAN1, CAN2, CAN3) via JST connectors, all supporting CAN FD mode.

120Ω Termination Resistor Control

Each CAN interface has a software-controlled 120Ω termination resistor. The GPIO mappings are as follows:

Interface	GPIO Chip	GPIO Line	Control Name
CAN0_120R_EN_3V3	3	0	CAN0 termination
CAN1_120R_EN_3V3	3	1	CAN1 termination
CAN2_120R_EN_3V3	3	2	CAN2 termination
CAN3_120R_EN_3V3	3	3	CAN3 termination
RS485_120R_EN_3V3	3	4	RS485 termination

You can view the corresponding GPIO lines using:

gpioinfo

CAN Classic Communication

Here we demonstrate data communication between CAN0 and CAN1.

Step 1. Install the CAN utilities:

sudo apt update
sudo apt install can-utils -y

Step 2. Configure the CAN interfaces:

sudo ip link set down can0
sudo ip link set down can1

sudo ip link set can0 type can bitrate 500000
sudo ip link set can1 type can bitrate 500000

sudo ip link set up can0
sudo ip link set up can1

Step 3. Open a new terminal to receive data on CAN1, and send data from CAN0:

# In a new terminal, listen on CAN1
candump can1

# In another terminal, send data from CAN0
cansend can0 123#DEADBEEF

CAN FD Mode

CAN FD (Flexible Data-Rate) extends the classic CAN protocol to support higher data rates and larger payloads (up to 64 bytes).

Step 1. Configure CAN0 and CAN1 for FD mode:

sudo ip link set down can0
sudo ip link set down can1

sudo ip link set can0 type can bitrate 500000 dbitrate 2000000 fd on
sudo ip link set can1 type can bitrate 500000 dbitrate 2000000 fd on

sudo ip link set can0 txqueuelen 2000
sudo ip link set can1 txqueuelen 2000

sudo ip link set up can0
sudo ip link set up can1

Step 2. Open a new terminal and test CAN FD communication:

# Listen on CAN1 with extended output
candump can1 -x

# Test 1: Send a 16-byte frame with BRS active
cansend can0 5AA##111223344556677889900AABBCCDD

# Test 2: Send a full 64-byte payload frame with BRS active
cansend can0 7DF##1101020203030404050506060707080809090A0A0B0B0C0C0D0D0E0E0F0F0111122223333444455556666777788889999AAAABBBBCCCCDDDDEEEEFFFF

info

5AA / 7DF is the CAN ID
## indicates a CAN FD frame
The digit after ## is the BRS (Bit Rate Switch) flag: 1 = BRS active
The following is the data payload (up to 128 hexadecimal characters for 64 bytes)

CAN Comprehensive Test Script

The following script performs a complete CAN FD test including dependency check, interface configuration, basic communication verification, and a 10-second stress test.

Create the test script:

vim can_test.sh

Paste the following content:

Click to expand CAN test script

#!/bin/bash

# Color output definitions
GREEN='\033[0;32m'
RED='\033[0;31m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

# Assign interfaces from arguments, default to can0 and can1 if empty
TX_DEV=${1:-can0}
RX_DEV=${2:-can1}

echo -e "${YELLOW}=== Jetson $TX_DEV <-> $RX_DEV Comprehensive Test Script ===${NC}"
echo -e "Note: Please ensure ${TX_DEV}_H -> ${RX_DEV}_H and ${TX_DEV}_L -> ${RX_DEV}_L are physically wired.\n"

# 1. Dependency Check
if ! command -v candump &> /dev/null; then
    echo -e "${YELLOW}[1/5] Installing can-utils...${NC}"
    sudo apt update && sudo apt install can-utils -y
else
    echo -e "${GREEN}[1/5] can-utils is already installed.${NC}"
fi

# 2. Reset and Configure Interfaces (Arbitration: 500K, Data: 2M, FD & BRS enabled)
echo -e "${YELLOW}[2/5] Configuring $TX_DEV and $RX_DEV (CAN FD Mode)...${NC}"
for dev in "$TX_DEV" "$RX_DEV"; do
    # Check if the interface exists in the system
    if ! ip link show "$dev" &> /dev/null; then
        echo -e "${RED}[ERROR] Interface $dev does not exist. Please check your spelling or hardware.${NC}"
        exit 1
    fi
    sudo ip link set down "$dev" 2>/dev/null
    sudo ip link set "$dev" type can bitrate 500000 dbitrate 2000000 fd on
    # Increase transmit queue length to prevent packet loss under heavy load
    sudo ip link set "$dev" txqueuelen 2000
    sudo ip link set up "$dev"
done
sleep 1

# 3. Basic Communication Test (Classic CAN Frame)
echo -e "${YELLOW}[3/5] Starting Basic Communication Test...${NC}"
# Listen for 1 frame on the receiver interface in the background and dump to a temp file
candump "$RX_DEV" -n 1 > /tmp/can_test_rx.log &
DUMP_PID=$!
sleep 0.5

# Send a single classic CAN frame from the transmitter interface
cansend "$TX_DEV" 123#DEADBEEF

# Wait for the background dump process to finish
wait $DUMP_PID 2>/dev/null

# Validate basic data
if grep -q "DE AD BE EF" /tmp/can_test_rx.log; then
    echo -e "${GREEN}[PASS] Basic communication successful! Data verified.${NC}"
else
    echo -e "${RED}[FAIL] Basic communication failed! No data received or data corrupted.${NC}"
    tail -n 2 /tmp/can_test_rx.log 2>/dev/null
    exit 1
fi

# 4. CAN FD High-Load Stress Test
echo -e "${YELLOW}[4/5] Starting CAN FD Stress & Stability Test (10 Seconds)...${NC}"
echo -e "--> $TX_DEV generating high-frequency 64-byte BRS random data stream to $RX_DEV..."

# Flood the bus using cangen (-f for FD, -b for BRS, -g 1 for 1ms interval)
cangen "$TX_DEV" -f -b -g 1 >/dev/null 2>&1 &
GEN_PID=$!

# Countdown timer
for i in {10..1}; do
    echo -ne "Remaining Time: ${i}s \r"
    sleep 1
done
echo ""

# Stop data generation
kill $GEN_PID 2>/dev/null
wait $GEN_PID 2>/dev/null
sleep 1

# 5. Analyze and Print Performance Report
echo -e "${YELLOW}[5/5] Generating Performance Report...${NC}"
echo "--------------------------------------------------"
echo -e "${YELLOW}$RX_DEV Receiver Statistics:${NC}"
# Extract packets and hardware error counters
ip -details -statistics link show "$RX_DEV" | grep -E -A 3 "(RX:|errors)"
echo "--------------------------------------------------"

# Smart assessment based on RX errors
ERRORS=$(ip -details -statistics link show "$RX_DEV" | grep -A 1 "RX: errors" | tail -n 1 | awk '{print $1}')
if [ "$ERRORS" ] && [ "$ERRORS" -gt 0 ]; then
    echo -e "${RED}[WARNING] Test completed, but $RX_DEV encountered $ERRORS errors/dropped packets during stress testing. Check your wiring and termination resistors!${NC}"
else
    echo -e "${GREEN}[SUCCESS] CAN FD stress test passed! Zero packet loss, zero hardware errors on $RX_DEV. Excellent board performance.${NC}"
fi

# Cleanup and tear down interfaces
for dev in "$TX_DEV" "$RX_DEV"; do sudo ip link set down "$dev"; done
rm -f /tmp/can_test_rx.log

Make the script executable and run it to test any two CAN interfaces:

chmod +x can_test.sh
./can_test.sh can0 can1

RS485

#Jetson 
sudo stty -F /dev/ttyAMA10 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo
sudo python3 -c 'import os,fcntl,struct; fd=os.open("/dev/ttyAMA10",os.O_RDWR|os.O_NOCTTY); fcntl.ioctl(fd,0x542F,struct.pack("IIIIIIII",3,0,20,0,0,0,0,0)); out=bytearray(32); fcntl.ioctl(fd,0x542E,out,True); print(struct.unpack("IIIIIIII",out)); os.close(fd)'
#(3, 0, 20, 0, 0, 0, 0, 0)

#PC
sudo stty -F /dev/ttyUSB0 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo
#jetson
sudo cat /dev/ttyAMA10
#PC
echo "hello from pc" | sudo tee /dev/ttyUSB0 >/dev/null

#PC 收
sudo cat /dev/ttyUSB0
#jetson
echo "hello from jetson" | sudo tee /dev/ttyAMA10 >/dev/null

DB9 (RS232 / RS422 / RS485)

The Robotics J601 provides one software-selectable DB9 serial interface. The DB9 port is connected to /dev/ttyAMA9 on the Jetson system and can be configured as RS232, RS422, or RS485 by setting the SW3 DIP switch.

Hardware Connection

The function of each DB9 pin depends on the selected communication mode. Refer to the table and the connector diagram below before wiring the adapter.

DB9 pin	RS232 mode	RS422 mode	RS485 mode
1	-	TXD- (B)	Data- (B)
2	RXD	TXD+ (A)	Data+ (A)
3	TXD	RXD+ (A)	-
4	-	RXD- (B)	-
5	GND	GND	GND
6	-	-	-
7	RTS	-	-
8	CTS	-	-
9	-	-	-

tip

For RS485 wiring, connect the USB-RS485 adapter A/D+ to DB9 pin 2, B/D- to DB9 pin 1, and GND to DB9 pin 5. Some USB-RS485 adapters label A/B in the opposite way. If the Jetson receives random bytes while the PC is not sending, swap A and B and test again.

Select the DB9 Mode with SW3

SW3 pulls each mode pin low when the switch is ON. In other words, ON = 0 and OFF = 1.

Mode	Schematic MODE value (MODE_0 MODE_1 MODE_2)	SW3-1 (MODE_0)	SW3-2 (MODE_1)	SW3-3 (MODE_2)	SW3-4 (SLEW)
RS232	`001`	ON	ON	OFF	ON recommended
RS422	`000`	ON	ON	ON	ON recommended
RS422	`100`	OFF	ON	ON	ON recommended
RS485	`010`	ON	OFF	ON	ON recommended
RS485	`110`	OFF	OFF	ON	ON recommended

note

For low-speed tests such as 115200 bps, keeping SW3-4 (SLEW) ON is recommended. This limits the driver slew rate and helps reduce noise on longer cables.

Enable the DB9 Transceiver

Before testing the DB9 port, keep the DB9 transceiver enabled from a dedicated Jetson terminal:

sudo gpioset --mode=wait gpiochip3 6=0

Keep this command running during the test. Press Enter in this terminal only after you finish testing.

RS232 Mode Test

Use a USB-to-RS232 adapter. If the adapter exposes separate wires, connect adapter TXD to DB9 pin 2 (RXD), adapter RXD to DB9 pin 3 (TXD), and adapter GND to DB9 pin 5 (GND). If you use a DB9-to-DB9 cable between two DTE devices, a null-modem cable or cross connection is usually required.

Step 1. Set SW3 to RS232 mode.

SW3-1	SW3-2	SW3-3	SW3-4
ON	ON	OFF	ON

Step 2. Configure the Jetson DB9 port:

sudo stty -F /dev/ttyAMA9 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo

Step 3. Configure the PC serial port.

On Linux:

PC_DEV=/dev/ttyUSB0
# If your adapter appears as /dev/ttyACM0, use:
# PC_DEV=/dev/ttyACM0

sudo stty -F $PC_DEV 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo

On macOS:

ls /dev/cu.* | grep -i usb

PC_DEV=/dev/cu.usbserial-0001
stty -f $PC_DEV 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo

For an interactive terminal on macOS, you can also use:

screen $PC_DEV 115200

Press Ctrl+A, then K, then Y to exit screen.

Step 4. Test PC to Jetson.

Run this on the Jetson:

sudo cat /dev/ttyAMA9

Then send data from the PC.

Linux PC:

echo "hello from pc to db9 rs232" | sudo tee $PC_DEV >/dev/null

macOS:

echo "hello from mac to db9 rs232" > $PC_DEV

Step 5. Test Jetson to PC.

Run this on the PC.

Linux PC:

sudo cat $PC_DEV

macOS:

cat $PC_DEV

Then send data from the Jetson:

echo "hello from jetson db9 rs232" | sudo tee /dev/ttyAMA9 >/dev/null

RS485 Mode Test

Use a USB-to-RS485 adapter. Connect adapter A/D+ to DB9 pin 2, adapter B/D- to DB9 pin 1, and adapter GND to DB9 pin 5.

Step 1. Set SW3 to one of the RS485 modes.

Recommended setting:

SW3-1	SW3-2	SW3-3	SW3-4
OFF	OFF	ON	ON

Alternative setting:

SW3-1	SW3-2	SW3-3	SW3-4
ON	OFF	ON	ON

Step 2. Configure the Jetson DB9 port and enable Linux RS485 mode:

sudo stty -F /dev/ttyAMA9 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo
sudo python3 -c 'import os,fcntl,struct; fd=os.open("/dev/ttyAMA9",os.O_RDWR|os.O_NOCTTY); fcntl.ioctl(fd,0x542F,struct.pack("IIIIIIII",5,0,20,0,0,0,0,0)); out=bytearray(32); fcntl.ioctl(fd,0x542E,out,True); print(struct.unpack("IIIIIIII",out)); os.close(fd)'

The expected RS485 configuration output is:

(5, 0, 20, 0, 0, 0, 0, 0)

Step 3. Configure the PC serial port.

Linux PC:

PC_DEV=/dev/ttyUSB0
# If your adapter appears as /dev/ttyACM0, use:
# PC_DEV=/dev/ttyACM0

sudo stty -F $PC_DEV 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo

macOS:

ls /dev/cu.* | grep -i usb

PC_DEV=/dev/cu.usbserial-0001
stty -f $PC_DEV 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo

Step 4. Test PC to Jetson.

Run this on the Jetson:

sudo cat /dev/ttyAMA9

Then send data from the PC.

Linux PC:

echo "hello from pc to db9 rs485" | sudo tee $PC_DEV >/dev/null

macOS:

echo "hello from mac to db9 rs485" > $PC_DEV

Step 5. Test Jetson to PC.

Run this on the PC.

Linux PC:

sudo cat $PC_DEV

macOS:

cat $PC_DEV

Then send data from the Jetson:

echo "hello from jetson db9 rs485" | sudo tee /dev/ttyAMA9 >/dev/null

RS422 Mode Test

Use a USB-to-RS422 adapter. Connect adapter TXD+ to DB9 pin 3 (RXD+), TXD- to DB9 pin 4 (RXD-), RXD+ to DB9 pin 2 (TXD+), RXD- to DB9 pin 1 (TXD-), and GND to DB9 pin 5 if the adapter provides a GND terminal.

Step 1. Set SW3 to one of the RS422 modes.

Recommended setting:

SW3-1	SW3-2	SW3-3	SW3-4
ON	ON	ON	ON

Alternative setting:

SW3-1	SW3-2	SW3-3	SW3-4
OFF	ON	ON	ON

Step 2. Configure the Jetson DB9 port:

sudo stty -F /dev/ttyAMA9 115200 cs8 -cstopb -parenb -ixon -ixoff -crtscts raw -echo

Step 3. Configure the PC serial port as 115200 8N1 with no flow control, then test both directions using the same cat and echo method shown in the RS232 section.

Troubleshooting

If /dev/ttyAMA9 cannot be opened, close other tools such as cat, minicom, or test scripts that may already be using the port.
If RS485 receives random bytes while the PC is not sending anything, the A/B lines are usually reversed or GND is not connected. Swap A/B and keep DB9 pin 5 connected to adapter GND.
If PC-to-Jetson works but Jetson-to-PC does not, make sure sudo gpioset --mode=wait gpiochip3 6=0 is still running in a separate Jetson terminal.
If RS485 still does not transmit from Jetson to PC, the RS485 direction polarity may be inverted for the selected mode. Try the same RS485 ioctl command with flags 3 instead of 5, and then test Jetson-to-PC again.
On macOS, use /dev/cu.* devices, for example /dev/cu.usbserial-0001. Do not use Linux-only commands such as stty -F or Linux RS485 ioctl commands on macOS.
For RS485, the USB-RS485 adapter usually handles half-duplex direction switching on the PC side. Only the Jetson DB9 port needs the Linux RS485 configuration shown above.

Ethernet

The Robotics J601 carrier board features high-speed Ethernet ports for wired network connectivity, with planned support for PTP and EtherCAT protocols.

Hardware Connection

Usage Instruction

To test Ethernet port speed, use iperf3 as follows:

Upload speed test:

iperf3 -c <server_ip> -B <bind_ip>

Download speed test:

iperf3 -c <server_ip> -B <bind_ip> -R

info

<server_ip> is the IP address of the iperf3 server. The client will connect to this server to perform a bandwidth test.
<bind_ip> binds the specified local IP address as the source of the test traffic.
The -R flag reverses the test direction for download speed testing.

M.2 Key E

The M.2 Key E interface is a standard M.2 connector primarily used for connecting wireless modules, such as Wi-Fi and Bluetooth, to expand wireless communication capabilities.

Hardware Connection

Usage Instruction

Step 1. Install the Wi-Fi driver firmware:

# Decompress firmware files
cd /lib/firmware/rtw88/
sudo zstd -d rtw8822c_fw.bin.zst -o rtw8822c_fw.bin
sudo zstd -d rtw8822c_wow_fw.bin.zst -o rtw8822c_wow_fw.bin

# Load the driver modules
sudo modprobe rtw88_core
sudo modprobe rtw88_pci
sudo modprobe rtw88_8822c
sudo modprobe rtw88_8822ce

Step 2. Reboot the device:

sudo reboot

Step 3. After reboot, bring up the wireless interface:

sudo ip link set wlP1p1s0 up

Step 4. Scan for available Wi-Fi networks:

sudo nmcli device wifi list ifname wlP1p1s0

Step 5. Connect to a Wi-Fi network:

sudo nmcli device wifi connect "your WiFi name" password "WiFi password" ifname wlP1p1s0

Bluetooth

Bluetooth functionality is available via the M.2 Key E slot.

Step 1. Open the Bluetooth control tool:

bluetoothctl

Step 2. Power on and scan for nearby Bluetooth devices:

power on
scan on

5G Module (M.2 Key B)

The M.2 Key B slot supports 5G module expansion, enabling high-speed cellular connectivity for robotics and edge AI scenarios.

Hardware Connection

Install the 5G module into the M.2 Key B slot and connect the antennas.

Usage Instruction

Step 1. Open the 5G module serial console:

sudo apt install -y minicom
sudo minicom -D /dev/ttyUSB3

Step 2. Enter interactive mode by pressing Ctrl+A then E.

Step 3. Test AT commands:

AT

Step 4. Check signal strength:

AT+CSQ

Step 5. Check the registered network operator:

AT+COPS?

Nano SIM

GPS

The 5G module on the M.2 Key B slot also provides GPS functionality for location tracking.

Usage Instruction

Step 1. Open the GPS AT command port:

sudo minicom -D /dev/ttyUSB2 -b 115200

Step 2. Enable the GPS receiver:

AT+QGPS=1

info

If the response is OK, the GPS receiver has been successfully started.
If the response is +CME ERROR: 549, GPS is already enabled — no need to enable it again.

Step 3. Exit minicom by pressing Ctrl+A then X, and select Yes to exit.

Step 4. After GPS is enabled, satellite data will stream from the GPS data port (typically /dev/ttyUSB1). Read the raw NMEA data:

sudo cat /dev/ttyUSB1

You should see standard GPS NMEA sentences such as:

$GPRMC,023011.00,A,2232.12345,N,11356.54321,E,0.026,,100626,,,A*7A
$GPGGA,023011.00,2232.12345,N,11356.54321,E,1,06,1.2,45.3,M,-2.3,M,,*6D
$GPGSV,3,1,11,01,65,120,42,03,45,210,38,08,30,045,35,11,15,290,31*74

note

Ensure you have a clear view of the sky for GPS signal acquisition. It may take a few minutes to get a valid fix.

Resources

Detailed hardware layout: TBD
Flashing guide: TBD
BSP release notes: TBD

Tech Support & Product Discussion

Thank you for choosing our products! We are here to provide you with different support to ensure that your experience with our products is as smooth as possible. We offer several communication channels to cater to different preferences and needs.

Interfaces Usage​

USB​

USB 3.2 Speed Test​

USB 2.0 Type-C Debug Port​

Windows​

Linux​

GMSL​

Supported GMSL Camera Models​

Hardware Connection​

Usage Instruction​

Use the Camera of Gemini 335Lg​

I2S​

Hardware Connection​

Usage Instruction​

UART​

Hardware Connection​

Usage Instruction​

RGB​

I2C​

Hardware Connection​

Usage Instruction​

CAN​

120Ω Termination Resistor Control​

CAN Classic Communication​

CAN FD Mode​

CAN Comprehensive Test Script​

RS485

DB9 (RS232 / RS422 / RS485)​

Hardware Connection​

Select the DB9 Mode with SW3​

Enable the DB9 Transceiver​

RS232 Mode Test​

RS485 Mode Test​

RS422 Mode Test​

Troubleshooting​

Ethernet​

Hardware Connection​

Usage Instruction​

M.2 Key E​

Hardware Connection​

Usage Instruction​

Bluetooth​

5G Module (M.2 Key B)​

Hardware Connection​

Usage Instruction​

Nano SIM​

GPS​

Usage Instruction​

Resources​

Tech Support & Product Discussion​

Interfaces Usage

USB

USB 3.2 Speed Test

USB 2.0 Type-C Debug Port

Windows

Linux

GMSL

Supported GMSL Camera Models

Hardware Connection

Usage Instruction

Use the Camera of Gemini 335Lg

I2S

Hardware Connection

Usage Instruction

UART

Hardware Connection

Usage Instruction

RGB

I2C

Hardware Connection

Usage Instruction

CAN

120Ω Termination Resistor Control

CAN Classic Communication

CAN FD Mode

CAN Comprehensive Test Script

DB9 (RS232 / RS422 / RS485)

Hardware Connection

Select the DB9 Mode with SW3

Enable the DB9 Transceiver

RS232 Mode Test

RS485 Mode Test

RS422 Mode Test

Troubleshooting

Ethernet

Hardware Connection

Usage Instruction

M.2 Key E

Hardware Connection

Usage Instruction

Bluetooth

5G Module (M.2 Key B)

Hardware Connection

Usage Instruction

Nano SIM

GPS

Usage Instruction

Resources

Tech Support & Product Discussion