setting up i2c on raspberry pi B+

[windell747]

I followed the instructions here

https://www.youtube.com/watch?v=FloRfIeuEoE

and when I run

sudo i2cdetect -y 0

I get

Error: Could not open file '/dev/i2c-0' or 'dev.i2c/0': No such file or directory

I get the same thing when I run
sudo i2cdetect -y 1

I'm not sure what I could be doing wrong. Any hints?

[SonOfAMotherlessGoat]

https://learn.adafruit.com/adafruits-ra ... guring-i2c

[windell747]

I ran through all the steps on that page including the double-check step and i2cdetect still doesn't work. Is there anything else that I can do to troubleshoot?

[W. H. Heydt]

Did you go into raspi-config and enable I2C? Under Jessie, you can use the graphical wrapper to do so.

[windell747]

Yup have done all those steps. I even reinstalled the os to try it again.

[joan]

Could you give the result of the following commands?

Code: Select all

uname -a

cat /etc/os-release

grep i2c /boot/config.txt

grep i2c /etc/modules

[windell747]

Thanks fellow RPiers. Here you go!

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pi@raspberrypi ~ $ uname -a
Linux raspberrypi 3.18.7+ #755 PREEMPT Thu Feb 12 17:14:31 GMT 2015 armv6l GNU/Linux
pi@raspberrypi ~ $ cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 7 (wheezy)"
NAME="Raspbian GNU/Linux"
VERSION_ID="7"
VERSION="7 (wheezy)"
ID=raspbian
ID_LIKE=debian
ANSI_COLOR="1;31"
HOME_URL="http://www.raspbian.org/"
SUPPORT_URL="http://www.raspbian.org/RaspbianForums"
BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"
pi@raspberrypi ~ $ grep i2c /boot/config.txt
dtparam=i2c1=on
dtparam=i2c_arm=on
pi@raspberrypi ~ $ grep i2c /etc/modules
i2c-bcm2708
i2c-dev
pi@raspberrypi ~ $

[joan]

Remove i2c-bcm2708 from /etc/modules.

[DougieLawson]

Can you post your whole /boot/config.txt (drop any comment # lines)?

[windell747]

I commented out the i2c-bcm2708 from /etc/modules, but still doesn't work.

Here is my /boot/config.txt ...

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dtparam=i2c1=on
dtparam=i2c_arm=on

[DougieLawson]

Is that the complete config.txt or is there anything else in it? Are you sure that's the one your system is using (if you're using NOOBS it may not be)?

Remove

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dtparam=i2c1=on

you don't need that.

What does an lsmod # that's ell, ess, emm, oh, dee command show?

[windell747]

Thanks a lot for helping!

Responding inline:

Is that the complete config.txt or is there anything else in it?
Just went to the file in nano and it looks like that is the complete file.

Are you sure that's the one your system is using (if you're using NOOBS it may not be)?
I'm not sure how to check to make sure that the OS is using this file.

Remove
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dtparam=i2c1=on
you don't need that.

Just did this and rebooted. Same behavior.


What does an lsmod # that's ell, ess, emm, oh, dee command show?

Here you go:

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pi@raspberrypi ~ $ lsmod
Module                  Size  Used by
i2c_dev                 6709  0 
evdev                  11000  6 
uio_pdrv_genirq         3666  0 
uio                     9897  1 uio_pdrv_genirq

[joan]

You are running an old kernel (3.18.7). This was around the time device tree was introduced. Unless you have a reason not to I'd update to a more recent (4.x) kernel with sudo rpi-update.