Salla100
Posts: 2
Joined: Wed Jan 13, 2021 6:14 pm

OSError: Cannot detect RPi-Sense FB device

Wed Jan 13, 2021 6:17 pm

I have my sense hat connectet to a raspberry pi 4 with wires. When i run a program i get the error OSError: Cannot detect RPi-Sense FB device. It is connected right and the LED is on. When i put it on the PI it works fine, it's just when i try to connect them with wires. How do i fix this?

alphanumeric
Posts: 2911
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: OSError: Cannot detect RPi-Sense FB device

Fri Jan 22, 2021 9:56 am

Missing a ground connection maybe? All the ground pins with a black horseshoe shaped blob on them in the following link, need to be connected.
https://pinout.xyz/pinout/sense_hat

Salla100
Posts: 2
Joined: Wed Jan 13, 2021 6:14 pm

Re: OSError: Cannot detect RPi-Sense FB device

Mon Jan 25, 2021 4:39 pm

alphanumeric wrote:
Fri Jan 22, 2021 9:56 am
Missing a ground connection maybe? All the ground pins with a black horseshoe shaped blob on them in the following link, need to be connected.
https://pinout.xyz/pinout/sense_hat
I have it connected to one ground. The leds are on. So does it need to be connected to all the ground pins?

alphanumeric
Posts: 2911
Joined: Tue Jan 19, 2016 2:17 pm
Location: Sydney, Nova Scotia, Canada

Re: OSError: Cannot detect RPi-Sense FB device

Tue Jan 26, 2021 12:12 pm

Yes, all the grounds marked with the black blob in the pinout need to be connected. On the Pi all the grounds are common and linked together. That's not always the case with a Hat though, they get linked together when its attached to the Pi GPIO header.

Peio64
Posts: 1
Joined: Mon Sep 14, 2020 7:29 pm

Re: OSError: Cannot detect RPi-Sense FB device

Wed Feb 10, 2021 3:07 pm

Hi,
I've got the same problem.
Alone the sense hat works well, but with the 26-pin extended header between the raspberry and the hat, the rainbow screen doesn't switch off after the boot and the rasperry doesn't detect it during a python program runs.

Do you know how to fix it ?

Thanks
Peio

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craigevil
Posts: 206
Joined: Wed Jan 27, 2021 5:22 am
Location: OZ

Re: OSError: Cannot detect RPi-Sense FB device

Tue May 11, 2021 1:42 am

Using an Adafruit Cyberdeck with a Sense HAT on my PI400. This is the error message:

Code: Select all

python -u "/home/pi/Projects/Sense Hat Drawing.py"
Traceback (most recent call last):
  File "/home/pi/Projects/Sense Hat Drawing.py", line 2, in <module>
    sense=SenseHat()
  File "/usr/lib/python3/dist-packages/sense_hat/sense_hat.py", line 39, in __init__
    raise OSError('Cannot detect %s device' % self.SENSE_HAT_FB_NAME)
OSError: Cannot detect RPi-Sense FB device
The lights are all lit up in the rainbow pattern.
Raspberry PI 400 Raspberry Pi OS (Unstable) Kernel: 5.10.42-v8+ aarch64 DE: MATE Ram 4GB
Debian - "If you can't apt install something, it isn't useful or doesn't exist"

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craigevil
Posts: 206
Joined: Wed Jan 27, 2021 5:22 am
Location: OZ

Re: OSError: Cannot detect RPi-Sense FB device

Tue May 11, 2021 2:55 am

Ok got past the last error by doing:
pip3 install sense-hat in a venv

Now I am getting this:

Code: Select all

 /home/pi/Projects/venv/bin/python "/home/pi/Projects/Sense Hat Drawing.py"
Traceback (most recent call last):
  File "/home/pi/Projects/Sense Hat Drawing.py", line 1, in <module>
    from sense_hat import SenseHat
  File "/home/pi/Projects/venv/lib/python3.9/site-packages/sense_hat/__init__.py", line 2, in <module>
    from .sense_hat import SenseHat, SenseHat as AstroPi
  File "/home/pi/Projects/venv/lib/python3.9/site-packages/sense_hat/sense_hat.py", line 10, in <module>
    import RTIMU  # custom version
ModuleNotFoundError: No module named 'RTIMU'
Raspberry PI 400 Raspberry Pi OS (Unstable) Kernel: 5.10.42-v8+ aarch64 DE: MATE Ram 4GB
Debian - "If you can't apt install something, it isn't useful or doesn't exist"

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