Which breakout board should I choose? Which libraries should I use in python?

[Pablo Paramio]

I am starting a project involving a Lepton 3.5 and a Raspberri Pi, but am struggling to find information on how to approach this.

I am quite new to this hardware and a python novice. My main objective is to capture pictures with the camera and to get the information of the temperature of each pixel.

I understand that the brightness of each pixel of the image produced by the lepton is proportional to the temperature of the object observed, but how do I get this image? There are some breakout boards with pins and other (more modern ones) with usbs. Are the usb boards meant for programming or just to get a "plug and play" image?

I would love to get some guidance onto which breakout board I should use.

On another note, I see there are some python libraries availible such as Pylepton or Flirpy. Will I be able to get an image with these libraries using a Raspberry Pi? And if so, how can I get the pixel "brightness" and consequently the temperature of said image?

Any type of help is much appreciated,

Thanks in advance.

[Dan Julio]

I designed a camera called tCam-Mini (that you can buy from Group Gets) that makes getting radiometric data from the Lepton 3.5 very easy.  It has two ways it can connect to the Pi.  Either via Wifi or with a direct connection.  You can use a python library to access the camera and process the raw data from the sensor along with its telemetry (which tells you things like what gain mode it is operating in, etc).

You can read about it here: https://github.com/danjulio/tCam

You want to go to the tCam-Mini and Python folders and peruse the readme files.  Please let me know if you have any questions.

Regards, Dan

[Pablo Paramio]

Thanks for the response. 

I have bought the tcam mini and have been doing some testing with it. I can manage to connect to it via wifi through the python programs, however I am having trouble connecting via GPIO to the raspberry pi as shown at the end of the python readme file. The connections are all exactly the same and both spi and uarts have been enabled. 

Trying the streamtest_hw.py I am able to get just one frame the first time I run the code and then get this error:

Traceback (most recent call last):
  File "/home/pablo/Downloads/tCam-main/tCam-main/python/examples/streamtest_hw.py", line 92, in <module>
    update()
  File "/home/pablo/Downloads/tCam-main/tCam-main/python/examples/streamtest_hw.py", line 48, in update
    image = convert(tcam.get_frame())
  File "/home/pablo/Downloads/tCam-main/tCam-main/python/examples/streamtest_hw.py", line 23, in convert
    dimg = base64.b64decode(img["radiometric"])
TypeError: byte indices must be integers or slices, not str

On the other hand, when trying to run dump_hw_image.py I get this other error:

  Traceback (most recent call last):
  File "/home/pablo/Downloads/tCam-main/tCam-main/python/examples/dump_hw_image.py", line 31, in <module>
    img = camera.get_image()
  File "/home/pablo/Downloads/tCam-main/tCam-main/python/examples/tcam.py", line 438, in get_image
    return self.frameQueue.get(block=True, timeout=timeout)
  File "/usr/lib/python3.9/queue.py", line 179, in get
    raise Empty
_queue.Empty

How can I solve this? I really need a physical connection for the project I am using this for.

Thanks in advance,

Pablo

[Dan Julio]

What version of python are you using?

[Arnaud Maillard]

I am actually interfacing a Lepton 3.5 on a Raspberry Pi 4 using a Breakout Board v2.0 ( 250-0577-00 FLIR Lepton | Cartes de développement, kits, programmateurs | DigiKey )   and the "pylepton" library (I use the lepton3-dev branch of the repo :  groupgets/pylepton at lepton3-dev (github.com))

I made some little modifications on the "pylepton_capture" script to get some radiometric images (pixels with proportional values to the temperature).

If you are interested in my solution, I can give you more information and the code I use !

Regards, Arnaud

[Pablo Paramio]

I am using python 3.9.2

[Pablo Paramio]

Thanks for the response Arnaud.

Im looking to get the temperature readings too, only that I am using the tCam mini board instead of the Breakout Board 2.0, so I don't think your code would work.

Either way, thanks for the response.

[Dan Julio]

I'm sorry for this very tardy reply.  For some reason google groups never let me know you had replied.  Did you get your problem solved?  I just loaded python 3.9.2 on my Pi and the program works fine.  I don't get the errors you showed.

[Daniel Wirch]

Hello Arnaud,

I am using the same setup as you are and i am struggling to implement those changes. Could you give me some information on how you did it?

Greetings,

Daniel

[Corey Levy]

Hi Arnaud,

I'm working on a similar project with more or less the exact same setup. If possible, could I see the code you use to acquire radiometric images?

As an end goal, I'm looking to determine the general location and peak temperature of a "hot spot" on a specified area in real-time via video stream from the Lepton 3.5.

Thanks,

Corey