Is it possible to use OAK-SOM to interface with FLIR Lepton 3.5?

Hi erik ,

Thanks for your update!

I think there is a workaround to bridge the image data between FLIR Lepton and OAK-SOM. I find this tutorial talking about how to send a partial image to esp32 through "spi message". So maybe i can inverse the data flow.

STEP 1. Use a MCU to get thermal image data from Lepton 3.5 and pack the thermal image data as image_part. The data will be send to OAK-SOM .

STEP 2. Implement a SPIIN node in OAK-SOM to receive SPI data and decode the packet as image_part.

Since the size of image raw data from lepton is 160 x 120 x 2 which is smaller than 300*300 bytes, I think it okay for OAK-SOM to receive whole image. The fps is about 9Hz. In theory, the minimum spi rate requires 160x120x2x9x8 = 2764800 bit/s (2.8Mbit/s)

Any idea?

Hi @erik ,

i just gave it a try. I took a USB 3.0 Hub as a bridge and connect to my OAK-FFC-3P. And I found that the camera will run in USB HS mode.

Connected cameras: [{socket: CAM_A, sensorName: IMX378, width: 4056, height: 3040, orientation: AUTO, supportedTypes: [COLOR], hasAutofocus: 1, name: color}, {socket: CAM_C, sensorName: OV9282, width: 1280, height: 800, orientation: AUTO, supportedTypes: [MONO], hasAutofocus: 0, name: right}]
Usb speed: HIGH
Device name: OAK-FFC-3P

However, if i connect to the host directly without USB 3.0 HUB, then the OAK-FFC-3P can run in USB SS mode.

Connected cameras: [{socket: CAM_A, sensorName: IMX378, width: 4056, height: 3040, orientation: AUTO, supportedTypes: [COLOR], hasAutofocus: 1, name: color}, {socket: CAM_C, sensorName: OV9282, width: 1280, height: 800, orientation: AUTO, supportedTypes: [MONO], hasAutofocus: 0, name: right}]
Usb speed: SUPER
Device name: OAK-FFC-3P

I have confirmed that the USB cable and USB hub support USB3.0.

The following is the python script:

import cv2
import depthai as dai

# Create pipeline
pipeline = dai.Pipeline()

# Define source and output
camRgb = pipeline.create(dai.node.ColorCamera)
xoutRgb = pipeline.create(dai.node.XLinkOut)

xoutRgb.setStreamName("rgb")

# Properties
camRgb.setPreviewSize(300, 300)
camRgb.setInterleaved(False)
camRgb.setColorOrder(dai.ColorCameraProperties.ColorOrder.RGB)

# Linking
camRgb.preview.link(xoutRgb.input)

# Connect to device and start pipeline
with dai.Device(pipeline, maxUsbSpeed=dai.UsbSpeed.SUPER_PLUS) as device:

    print('Connected cameras:', device.getConnectedCameraFeatures())
    # Print out usb speed
    print('Usb speed:', device.getUsbSpeed().name)
    # Bootloader version
    if device.getBootloaderVersion() is not None:
        print('Bootloader version:', device.getBootloaderVersion())
    # Device name
    print('Device name:', device.getDeviceName())

    # Output queue will be used to get the rgb frames from the output defined above
    qRgb = device.getOutputQueue(name="rgb", maxSize=4, blocking=False)

    while True:
        inRgb = qRgb.get()  # blocking call, will wait until a new data has arrived

        # Retrieve 'bgr' (opencv format) frame
        cv2.imshow("rgb", inRgb.getCvFrame())

        if cv2.waitKey(1) == ord('q'):
            break

I tried to open the device by the script with dai.Device(pipeline, maxUsbSpeed=dai.UsbSpeed.SUPER_PLUS) as device:.

Any idea?