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Newb: IO Pi Plus, Raspberry Pi 2+ - can't see board

8882 Views - Created 15/11/2022

15/11/2022

Posted by:
Andy_hollywood

Hello Everyone,

I'm just getting started with the Pi and indeed i2C, I have bought the "IO Pi Plus", soldered on the connections and mounted it on top of my Pi2+,

followed the instructions here (https://www.abelectronics.co.uk/kb/article/23/python-library-and-demos and here https://www.abelectronics.co.uk/kb/article/1/i2c-part-2---enabling-i-c-on-the-raspberry-pi) and now with the baord connected running:

pi@seeburg:~ $ sudo i2cdetect -y 1
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: -- -- -- -- -- -- -- --

I have enabled i2c on the pi... not sure how to debug it.

I have checked with my meter that the board has power from 5v -> gnd on both buses and the other terminals...

Wondered if there was anything obvious i should try?

As an aside - i added a power button on teh GPIO pins on the GPIO extension pins on the IO Pi Plus which appears to work great - so feel the board is getting power...

Any ideas?

15/11/2022

Posted by:
andrew

Location:
United Kingdom

Hello Andy

In the photo, it looks like you have a green wire connected to pin 5 on the GPIO header. What is this wire being used for? The IO Pi Plus uses pins 3 and 5 for the I2C bus so if you have any external connections to either of those pins it can stop the I2C bus from working correctly.

15/11/2022

Posted by:
Andy_hollywood

Ah so those wires are for a power switch, and its LED - so i can turn it on and off....

GPIO 3 (PIn 5) is the switch, GPIO 4 (pin 5) and PIn 6 is turning on and off the LED..

#!/usr/bin/env python

import RPi.GPIO as GPIO
import subprocess
import time

GPIO.setmode(GPIO.BCM)
GPIO.setup(3, GPIO.IN, pull_up_down=GPIO.PUD_UP)

GPIO.setup(4, GPIO.OUT);
GPIO.output(4, GPIO.HIGH);

GPIO.wait_for_edge(3, GPIO.FALLING)
time.sleep(5)

GPIO.output(4, GPIO.LOW)
subprocess.call(['shutdown', '-h', 'now'], shell=False)

So sounds like i've been over zleaous on that - hadn't realised pins 3 and 5... i'll remove those and see what gives.

Thanks for your help.

15/11/2022

Posted by:
Andy_hollywood

So this worked. I removed my little service so it freed up the pins.

and voila! All working a treat.

thanks so much!

27/03/2023

Posted by:
AntonioCraig

Thank you for sharing interesting knowledge

02/04/2023

Posted by:
joet

Location:
Wachapreague VA US

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