28
votes
Accepted
Updating Python 3.7 to 3.8 on Raspberry Pi
Why? Just because it takes a while for distributions to integrate new versions.
Here's what I did to install Python 3.8.5 on my rpi:
sudo apt-get install -y build-essential tk-dev libncurses5-dev \
...
- 546
16
votes
Accepted
Python script fails with 'ImportError' when run from rc.local
It's worth noting that rc.local is run by root, rather than the pi user which you are likely using at your terminal. It seems likely that your installation for the telepot module is installed only for ...
- 6,278
16
votes
Accepted
Failed to create MMAL component b'vc.ril.camera': Out of memory
This error was resolved when I disconnected and reconnected my camera module.
Somehow my camera module must have been wiggled loose when I was working with it and the Pi was not able to detect the ...
- 422
12
votes
Accepted
How fast can GPIO pins toggle?
There are some benchmarks from Henner Zeller's repository on GitHub which claimed that directly outputting data to the GPIO could achieve up to 65.8 MHz on a Raspberry Pi 3 (not B+, mind, but I ...
- 6,278
12
votes
Accepted
Bluetooth library for Raspberry Pi
There are many options for using Python for Bluetooth Low Energy on Raspberry Pi. Maybe too many options and that is why there is maybe no one winner for all situations.
BLE defines multiple roles ...
- 1,435
9
votes
Accepted
How does Raspbian know it's been installed in a Pi or Compute Module?
The command is:
cat /proc/cpuinfo
And the list over the different hardware is here: http://elinux.org/RPi_HardwareHistory#Board_Revision_History
Table over hardware differences: https://www....
- 2,726
9
votes
I want to run a Python 3 script on startup and in an endless loop on my Raspberry Pi
Your script is a typical use of a service. Usually a service is started once and then it is running in background until it is stopped by the service manager. The service manager can restart a script ...
- 41.9k
8
votes
Accepted
Installing libraries via pip is taking forever. Raspberry pi 3b+
Building scipy from source takes about 1hr20. Pre-compiled wheels are available from piwheels.org, so you can install it from there without building yourself.
Raspbian Stretch is pre-configured to ...
- 2,441
8
votes
Accepted
cron not executing python3
As is typical with crontab issues. The environment is not the same as your user or even a sudo/root shell , and env python3 may not return anything (env simply searches through
Instead you should ...
- 2,983
7
votes
Accepted
How to connect MySQLdb in Python 3?
You have to install the MySQLdb package:
sudo apt-get update
then
sudo apt-get install python3-dev libmysqlclient-dev
This took a while and finally:
sudo pip3 install mysqlclient
now it should ...
- 350
7
votes
Accepted
Only 1 thread starts when multi-threading in Python 3
Neither thread is actually started.
Instead of
threading.Thread(target = thread1())
you should use
threading.Thread(target = thread1)
At the moment you are calling a function which never returns ...
- 70.5k
7
votes
Accepted
Open a Folder in the File Manager by a Python Script
For asynch :
import os
myfolder="/home/pi/Desktop"
def onMyButtonClick():
os.system("pcmanfm \"%s\"" % myfolder)
For asynch or ̶s̶y̶n̶c̶h̶ use python subprocess Popen :
import subprocess
...
- 2,147
6
votes
Accepted
Is it necessary to release Raspberry Pi Camera before rebooting? If so how do I do it?
There is NO NEED to do anything before a reboot.
If you issue a sudo reboot command Linux will manage an orderly shutdown of the software.
This is, however, a poor way of ensuring a reliable 24/7 ...
- 58.6k
6
votes
How can I use OpenCV with Python 3 on a Raspberry Pi?
It says "Cannot open shared object".
ImportError:libQTtest.so.4:cannot open shared object file:no such file or directory
Yes, but it does not say this is because "the library isnt shared with it"...
- 58.5k
6
votes
GPIO LED Python
Thats because by using 'GPIO.setmode(GPIO.BCM)' you are specifying the BCM numbering convention. GPIO 18 is actual pin number 12.
- 6,827
6
votes
Failed building wheel for cffi on Model 3B+
ciffi depends on libffi, so I had to first install the libffi-dev package. Install it using:
sudo apt install libffi-dev
The package might be different if you are using some other distro.
- 216
6
votes
Accepted
Callback parameters to GPIO.add_event_detect?
I ran into the same issue. You can solve it without using another library.
This is how you do it.
def button_callback(button):
print('Button {} pressed'.format(button))
GPIO.add_event_detect(...
- 76
6
votes
Accepted
How to automatically rerun Python script if error occurs
You can run the script as service using systemd. Just create a Unit file with:
rpi ~$ sudo systemctl --force --full edit myscript.service
In the empty editor insert these statements, save them and ...
- 41.9k
6
votes
Accepted
Error Installing TensorFlow on Rasperry Pi 3 B
Okay, I have solved my problem. I reinstalled Python 3.6.
Then I used this command sudo apt-get install libhdf5-dev and then sudo pip install tensorflow and installed TensorFlow successfully!
I ...
- 334
5
votes
Accepted
Pip3 install throwing error on raspberry pi 3 Raspbian-Jessie
From the error log, it seems to be an issue with the SSL protocol being used:
File "/usr/lib/python3/dist-packages/OpenSSL/SSL.py", line 1149, in _raise_ssl_error
raise WantReadError()
OpenSSL....
- 166
5
votes
How fast can GPIO pins toggle?
If you want to synchronously transmit data at 50MHz frequency (that's how I read "pins to be toggled on the schedule of a ~50 mhz FPGA clock"), you will absolutely need to use the same clock source ...
- 27.7k
5
votes
Accepted
no module named 'speech_recognition'
Your tag says python3. If you are running your code in python3 you need to install speechrecognition with pip3.
- 871
5
votes
Accepted
how to install protobuf in raspberrypi3 b+ stretch?
I suggest to install protobuf in raspberrypi 3 b+ from the default repository. With:
rpi ~$ apt list *protobuf*
you will find some packages supporting protocol buffers. Just install what you want, ...
- 41.9k
5
votes
Launch a GUI Tkinter program on boot
From Sparkfun website:
The three methods covered in this tutorial are:
rc.local - Likely the easiest and simplest way to get your program to run on boot. The downside is that tasks started with rc....
- 2,147
5
votes
Accepted
Python3.7 with Numpy on Raspbian
The solution was surprisingly simple:
Install an older Numpy version - I went with:
sudo python3.7 -m pip install 'numpy>1.0, <1.15' --force-reinstall
The installation took looong, but I'm ...
- 191
5
votes
Accepted
5v/12v power source/submersible water pump/RPI/relay. What kind of combination is suitable?
12V pump will require 12V PSU. 20LPM is a pretty reasonable flow rate for a small pump so your pump PSU will need to have enough power to drive the pump - check the max current draw on startup (which ...
- 66
5
votes
Accepted
Raspberry Pi Cluster for Computation
For a rough measurement, I generated a 2000 x 2000 matrix with random integer entries between 0 and 9, and timed computation of the determinant in SageMath (I did this twice, with similar results). On ...
- 166
5
votes
Accepted
Can I use the Python Interpreter to list a modules' classes and methods, as well as descriptions?
This is not a Pi specific question, but all the normal python commands work (at least as well as in any python shell) e.g.
import gpiozero
help(gpiozero)
dir(gpiozero)
To document the Button class ...
- 58.6k
4
votes
Accepted
Is there a problem with using deprecated os.popen?
According to docs.python.org os.popen() is stacked on top of subprocess.Popen() - at least for Python 3.x:
This is implemented using subprocess.Popen; see that class’s documentation for more ...
- 15.8k
4
votes
Accepted
Raspberry pi no module named socket server
python is never Python 3 in Debian, even if you have installed Python 3. Python 3 will install as python3, and the python binary points to Python 2 (see PEP 394) instead.
In Python 2, the ...
- 6,278
Only top scored, non community-wiki answers of a minimum length are eligible