Standalone mode¶
Standalone / Hostless / On-The-Edge mode means that the OAK camera isn’t connected to a host computer. This can be achieved by first flashing the bootloader and then flashing the pipeline and assets (NN models) to the OAK’s flash memory.
Standalone mode is only possible on OAKs that have on-board flash memory, which are currently OAK POE and OAK IOT camera models.
Converting a demo to standalone mode¶
Since there won’t be any communication between the host and the device, you first need to remove all XLinkOut and XLinkIn nodes. This means that the device will only communicate with the “outside world” via either SPI (SPIOut/SPIIn) or Script node (GPIO/UART or network protocols if you have OAK POE mode; HTTP/TCP/UDP…).
Next thing you can also remove the host-side code, which usually looks something like this:
with dai.Device(pipeline) as device:
videoQ = device.getOutputQueue("video")
faceDetQ = device.getOutputQueue("face_det")
nnQ = device.getOutputQueue("nn")
while True:
frame = videoQ.get().getCvFrame()
# ...
After you remove all host-side code, you would only be left with the Pipeline definition (with nodes/links). Since device no longer communicates with the host, you need to “route” your program’s output through either SPI or script node, as mentioned above.
Flash the bootloader¶
The Bootloader is packaged together with the depthai, so if you have the latest depthai version, you can flash the latest bootloader version. To flash the bootloader, we suggest using the Device Manager. To view the API code behind it, see Flash Bootloader example code.
Flash the pipeline¶
After you have standalone Pipeline defined and Bootloader already flashed on the device, you can flash the pipeline to the device, along with its assests (eg. AI models). You can flash the pipeline with the following snippet:
import depthai as dai
pipeline = dai.Pipeline()
# Define standalone pipeline; add nodes and link them
# cam = pipeline.create(dai.node.ColorCamera)
# script = pipeline.create(dai.node.Script)
# ...
# Flash the pipeline
(f, bl) = dai.DeviceBootloader.getFirstAvailableDevice()
bootloader = dai.DeviceBootloader(bl)
progress = lambda p : print(f'Flashing progress: {p*100:.1f}%')
bootloader.flash(progress, pipeline)
After successfully flashing the pipeline, it will get started automatically when you power up the device. If you would like to change the flashed pipeline, simply re-flash it again.
Alternatively, you can also flash the pipeline with the Device Manager. For this approach, you will need a Depthai Application Package (.dap), which you can create with the following script:
import depthai as dai
pipeline = dai.Pipeline()
# Define standalone pipeline; add nodes and link them
# cam = pipeline.create(dai.node.ColorCamera)
# script = pipeline.create(dai.node.Script)
# ...
# Create Depthai Application Package (.dap)
(f, bl) = dai.DeviceBootloader.getFirstAvailableDevice()
bootloader = dai.DeviceBootloader(bl)
bootloader.saveDepthaiApplicationPackage(pipeline=pipeline, path=<path_of_new_dap>)
Clear flash¶
Since pipeline will start when powering the device, this can lead to unnecesary heating. If you would like to clear the flashed pipeline, use the code snippet below.
Warning
Code below doesn’t work yet. We will be adding “flashClear” helper function to the library.
import depthai as dai
(f, bl) = dai.DeviceBootloader.getFirstAvailableDevice()
if not f:
print('No devices found, exiting...')
exit(-1)
with dai.DeviceBootloader(bl) as bootloader:
bootloader.flashClear()
Factory reset¶
In case you have soft-bricked your device, or just want to clear everything (flashed pipeline/assets and bootloader config), we recommend using the Device Manager. Factory reset will also flash the latest bootloader.