One Up access GPIO

ONE UP
1

I cannot access the GPIO pins without running as root, i get the following error from python:

RuntimeError: Cannot determine SOC peripheral base address.

the same code runs without issue on a pi500

2

Nothing to do with the platform, you need to make sure you add the gpio group to your account:

Using the following:

sudo usermod -aG gpio <yourAccountHere>

gpio is needed, however you may want to add i2c and spi as well. Note you will need to log out and log back in to enable the group(s) addition

3

Thanks, I already tried that but still get:

RuntimeError: Cnnot determine soc base address

when I run my code

4

Not knowing that you are trying to do makes this a little more difficult, however:

  1. If its old code that worked on a Raspberry PI 4.. this may indicate you are using libraries that are not supported on the RPI5… such as RPI.GPIO, wiriingPI, and pigpio…

You may need rpi-lgpio instead, or use gpiozero.

  1. Post more of the code so we can see whats going wrong and where… just message is limiting…
5

I am pretty certain the code was running with sudo & as per my original post was working fine on a Pi500, I will create a minimum code example & post later if it still fails.

6

Copy the following and run it… using python3

import RPi.GPIO as GPIO
import time

WAIT_TIME = 1

class GetCaseFanSpeed:
    TACH = 18
    PULSE = 2
    def __init__( self, tachPin = TACH):
        self._tachPin = tachPin
        self._rpm = 0
        self._t   = time.time()
        self.GPIO = GPIO
        self.GPIO.setmode( self.GPIO.BCM )
        self.GPIO.setwarnings( False )
        self.GPIO.setup( self._tachPin, self.GPIO.IN, pull_up_down=self.GPIO.PUD_UP )
        self.GPIO.add_event_detect( self._tachPin, self.GPIO.FALLING, self._calcRPM )
        
    def __del__( self ):
        self.GPIO.cleanup()
        
    def _calcRPM( self, n ):
        dt = time.time() - self._t
        if dt < 0.005: return # Reject spuriously short pulses
        
        freq = 1 / dt
        self._rpm = (freq / GetCaseFanSpeed.PULSE) * 60
        self._t = time.time()
    
    @property
    def RPM( self ):
        return self._rpm
    
if __name__ == "__main__":
    
    fanSpeed = GetCaseFanSpeed()

    try:
        for i in range( 10 ):
            print( f"{fanSpeed.RPM:.0f} RPM" )
            time.sleep( 2 )
        
    except KeyboardInterrupt:
        GPIO.cleanup()
7

i am still getting the same error,

very confusing as this is a stock install

8

Its gotta be incorrect libraries…

9

I think you are correct

sudo apt reinstall python3-rpi-lgpio

did the trick for your code, now to start debugging mine again :slight_smile:

one last question How do I get it includes in a python venv

python -m venv (venvname) does not seem to include it

10

You need to make sure that the libraries are installed in the python venv.

11

Thanks, I sorted that & then found then installing the Pimoroni Blinkt library over wrote it, restoring the correct version solved the initial error & revealed som incompatabilities in the pimoroni libruary that I am working through.

many thanks for the pointers