Cannot detect color sensor

[ftheriault]

Hi all,

I'm quite new using ev3dev, so please don't be too hard on me.

I have installed ev3dev and executed the CPP samples. The ev3dev-lang-test program seems to detect properly my motors and my touch sensor, though it doesn't detect my EV3 color sensor. I also tried a NXT color sensor, without more success...

Am I the only one having this issue?

Thanks!

[dlech]

There is no driver for the NXT Color sensor yet, so no, you are not the only one. :wink:

The EV3 color sensor should work though. What kernel version are you using?

[ftheriault]

Thanks for the quick reply!

I am using the following image version : ev3dev-jessie-2014-12-01.img

Kernel is :

Linux ev3dev 3.16.1-7-ev3dev #2 PREEMPT Tue Nov 25 11:24:38 CST 2014 armv5tejl GNU/Linux

[dlech]

There are some breaking changes in the more recent kernels, but I think that one should work. You can see what is is /sys/class/msensor to see if the sensor is actually there. If it is there, then then I am not sure what the problem is.

[ftheriault]

Funny thing is... it is not there :(

I see my touch sensor, but that's it... any clue?

[dlech]

Have you updated other packages? Namely, what is the version from dpkg -s ev3dev-base. If you upgraded this package (apt-get upgrade) without upgrading the kernel (apt-get dist-upgrade), then this is why it is not working. If you do upgrade the kernel though, there are some breaking changes (see #29) and you will have to fix the cpp library.

[ftheriault]

Humm... the only thing I did was : apt-get install build-essential, for the gcc compiler (I did not know we used CC at the time...). Could it be the problem?

Here is the result of dpkg -s ev3dev-base, which I did not upgrade :

Package: ev3dev-base
Status: install ok installed
Priority: required
Section: metapackages
Installed-Size: 37
Maintainer: David Lechner 
Architecture: armel
Version: 8.0
Depends: ev3dev-bluetooth (>= 8.0), ev3dev-console (>= 8.0), ev3dev-flash-kernel (>= 8.0), ev3dev-gadget (>= 8.0), ev3dev-i2c (>= 8.0), ev3dev-leds (>= 8.0), ev3dev-ports (>= 8.0), ev3dev-uart (>= 8.0)
Description: Meta package that installs all of the required ev3dev packages.
Homepage: http://www.ev3dev.org

[ftheriault]

Checking my command history, I see that at one point, I tried to install ev3dev-c (see in4lio project, on github). If you think this can be the problem, I'll just recreate the image...

[dlech]

ev3dev-base 8.0 is for kernel v3.16.1.-8-ev3dev and higher which is why UART sensors are not working. (So, you did upgrade even if not intentionally.)

So, your options are: you can recreate the image and use the old versions or you can upgrade the kernel and help migrate the cpp library to the new kernel version.

[ftheriault]

Thanks David, I really appreciate the time that you took to help. Since I am way too novice at this point, I'll just revert a fresh image.

[dlech]

You are welcome! And the changes are just changing strings for things that were renamed, so even a novice could do it if you are feeling adventurous.