AR0234 kernel driver for NVIDIA Jetson

NVIDIA Jetson kernel driver for Onsemi AR0234, a 2.3 MP global shutter 1/2.6" CMOS sensor.

• 2-lane MIPI CSI-2
• 10-bit RAW output
• 1920×1200 @ 60 fps

Setup

Install required tools:

sudo apt install -y --no-install-recommends dkms

Clone this repository:

cd ~
git clone https://github.com/Kurokesu/ar0234-jetson-driver.git
cd ar0234-jetson-driver/

Run setup script:

sudo ./setup.sh

Setup script:

• Fetches NVIDIA device tree headers required for build
• Builds and installs kernel module via DKMS
• Builds and copies device tree overlay (.dtbo) to /boot

Optionally, install the ISP tuning file:

sudo cp ./tuning/camera_overrides.isp /var/nvidia/nvcam/settings

To restore default ISP parameters, remove the overrides file:

sudo rm /var/nvidia/nvcam/settings/camera_overrides.isp

Use Jetson-IO to configure the CSI connector:

sudo /opt/nvidia/jetson-io/jetson-io.py

Navigate through the menu:

1. Configure Jetson CSI Connector (named "22pin" on 6.2.2, "24pin" on 6.2.1)
2. Configure for compatible hardware
3. Select port configuration:
   • Camera AR0234-A - cam0
   • Camera AR0234-C - cam1
   • Camera AR0234 Dual - cam0 + cam1

4. Save pin changes
5. Save and reboot to reconfigure pins

After reboot, verify sensor is detected:

sudo dmesg | grep ar0234

Image output

GStreamer

Single:

gst-launch-1.0 -e nvarguscamerasrc sensor-id=0 ! \
   'video/x-raw(memory:NVMM),width=1920,height=1200,framerate=30/1' ! \
   queue ! nvvidconv ! queue ! nveglglessink

Dual:

gst-launch-1.0 -e \
   nvarguscamerasrc sensor-id=0 ! \
      'video/x-raw(memory:NVMM),width=1920,height=1200,framerate=30/1' ! \
      queue ! nvvidconv ! queue ! nveglglessink \
   nvarguscamerasrc sensor-id=1 ! \
      'video/x-raw(memory:NVMM),width=1920,height=1200,framerate=30/1' ! \
      queue ! nvvidconv ! queue ! nveglglessink

NVIDIA sample camera capture application

nvgstcapture-1.0 --sensor-id 0

Trigger modes

AR0234 supports two external trigger modes. Both use TRIG pin on camera module as external signal input. TRIG is a 1.8V logic level input wired directly to sensor. Trigger pulse only initiates capture, exposure time remains controlled by sensor's integration time register.

TRIG and FLASH signals are available on AUX connector:

Full module pinout and AUX connector part number are documented in 234x-CSI wiki page.

trigger_mode	Description
0	Off (free-running, default)
1	External trigger (pulsed/automatic)
2	Sync-sink

external-trigger

Sensor stays in standby and waits for activity on TRIG pin. Exposure and readout happen sequentially: readout does not begin until exposure is complete. Two sub-modes are available:

• Pulsed: each high pulse on TRIG pin captures a single frame (minimum pulse width 125 ns, 3 EXTCLK cycles at 24 MHz). Framerate is determined by pulse frequency.
• Automatic: if TRIG signal stays high, sensor outputs frames continuously at configured framerate.

echo 1 | sudo tee /sys/module/nv_ar0234/parameters/trigger_mode

After enabling trigger mode start sensor stream via v4l2. Frames will arrive when there is signal on TRIG.

v4l2-ctl -d /dev/video0 --set-ctrl override_capture_timeout_ms=-1 --stream-mmap --stream-count=1000 --stream-to=/dev/null

Without override_capture_timeout_ms=-1 capture fails if first trigger arrives later than default 2.5 s VI timeout. On Argus path use enableCamInfiniteTimeout=1 instead.

sync-sink

Sensor streams continuously but locks frame timing to external TRIG signal. Unlike external-trigger, exposure and readout overlap (pipelined), so higher framerates are possible. Trigger period must not be shorter than configured frame length.

echo 2 | sudo tee /sys/module/nv_ar0234/parameters/trigger_mode

Disable trigger

echo 0 | sudo tee /sys/module/nv_ar0234/parameters/trigger_mode

Flash output

AR0234 has a FLASH output pin (1.8V logic level) that goes HIGH during sensor exposure, useful for synchronizing external illumination such as strobes or LEDs.

Parameter	Type	Description
flash	bool	Enable flash output on FLASH pin
flash_delay	int	Signed delay (-127..127), negative = lead, positive = lag

To enable flash output:

echo Y | sudo tee /sys/module/nv_ar0234/parameters/flash

The flash signal start can be shifted relative to exposure using flash_delay:

• Negative values (lead): flash starts before exposure, extending total flash time
• Positive values (lag): flash starts after exposure begins, shortening total flash time

flash_delay accepts values in the range of -127 to 127, where each unit is approximately 6.8 µs (2-lane).

# Flash starts ~68 µs before exposure (2-lane)
echo -10 | sudo tee /sys/module/nv_ar0234/parameters/flash_delay

# Flash starts ~68 µs after exposure begins (2-lane)
echo 10 | sudo tee /sys/module/nv_ar0234/parameters/flash_delay

Disable flash output:

echo N | sudo tee /sys/module/nv_ar0234/parameters/flash

Test mode

AR0234 has a built-in test pattern generator for verifying data validity.

Enable test pattern:

# 100% color-bar test pattern (test_mode = 2)
echo 2 | sudo tee /sys/module/nv_ar0234/parameters/test_mode

Turn test pattern off:

echo 0 | sudo tee /sys/module/nv_ar0234/parameters/test_mode

Test pattern code	Description
0	Off (normal operation)
1	Solid color
2	100% color bar
3	Fade-to-grey color bar
256	Walking 1s (10-bit)

Development builds

For manual builds without DKMS:

make              # build everything (dtbo + kernel module)
sudo make install # copy dtbo to /boot, rmmod + insmod

Note

Module is loaded immediately via insmod but won't persist across reboots. Use sudo ./setup.sh for permanent installation via DKMS.

Individual targets:

make dtbo      # build only the device tree overlay
make module    # build only the kernel module
make clean     # remove build artifacts

Build artifacts are placed in ./build.