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LED Backpack - Raspberry Pi Ver 2 - Error accessing I2C Address
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LED Backpack - Raspberry Pi Ver 2 - Error accessing I2C Address

by Sakhara on Wed Oct 24, 2012 12:11 am

Looking for a little help on changing the IC2 Bus from "/dev/i2c-0" to "/dev/i2c-1" in the Adafruit Library.

When following the instructions on this page:
http://learn.adafruit.com/matrix-7-segm ... it-library
8x8_pixels.py output ends repeating:
Error accessing 0x70: Check your I2C address

I2cdetect -y -0
Returns no devices
I2cdetect -y -1
Returns the LED Backpack on 70

I assume the Library, Class, Scripts are setup for /dev/i2c-0.
I've searched the forum and dug through some of the code but cannot find where to successfully change the 'port'
Any pointers on where to change the 'port' reference in the above library?

OS = stock Raspbian “wheezy” not Occidentalis (Yes I know, I'll give it a try next)

Thanks!
Sakhara
 
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Joined: Tue Oct 23, 2012 11:57 pm

Re: LED Backpack - Raspberry Pi Ver 2 - Error accessing I2C Address

by Sakhara on Wed Oct 24, 2012 12:16 am

Found it and fixed.
If anybody else finds this:

Change
Adafruit_I2C.py

class Adafruit_I2C :

def __init__(self, address, bus=smbus.SMBus(0), debug=False):
to
def __init__(self, address, bus=smbus.SMBus(1), debug=False):
Sakhara
 
Posts: 2
Joined: Tue Oct 23, 2012 11:57 pm

Re: LED Backpack - Raspberry Pi Ver 2 - Error accessing I2C Address

by Docteh on Fri Oct 26, 2012 1:56 am

Which board revision do you have? do you have mounting holes on yours? I read that they swapped the two i2c busses around between revisions.
Docteh
 
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Joined: Fri Oct 26, 2012 1:49 am

Re: LED Backpack - Raspberry Pi Ver 2 - Error accessing I2C Address

by VOYAGERUSA on Mon Nov 19, 2012 12:08 pm

tnx SAKARA been trying to figure it out on mine also all my projects i have on my 256 didnt work on 512 because of this and not good at code python.
Hope the put in a check of model and swap ports/bus to 1 with the 512 save time unless you use camera header it has 0 now.
Voyager
VOYAGERUSA
 
Posts: 13
Joined: Tue Sep 11, 2012 7:54 pm