author: "@dlech"

title: "Kernel Release Cycle 16"

There is nothing too exciting in this release. Most of the changes are for

adding support for a new BeagleBone cape that is being developed.

This release includes one bug fix. Support for polling the `status` attribute

of the tacho motor class has been restored for EV3. (It is still broken for

BrickPi and PiStorms.)

Here is an example of how to make use of this feature:

{% highlight python %}

#!/usr/bin/env python3

import glob

import select

motors = glob.glob('/sys/class/tacho-motor/motor*')

p = select.poll()

lookup = {}

for m in motors:

# get the output port name for each motor

with open(m + '/address', 'r') as a:

name = a.read().strip()

# get a handle to the status attribute

s = open(m + '/state', 'r')

# register the status attribute with the poll object. POLLPRI is important!

p.register(s, select.POLLPRI)

# save these for later

lookup[s.fileno()] = (name, s)

while True:

# wait for a an event

for fd, event in p.poll():

# get the info for the motor that caused the event

name, s = lookup[fd]

if event & select.POLLPRI:

# print info about the event

s.seek(0)

print(name, s.read().strip())

else:

print(name, 'Poll error!')

{% endhighlight %}

In this round of releases, we have:

* `v4.4.24-16-ev3dev-ev3` for EV3.

* `v4.4.24-ti-rt-r55-16-ev3dev-bb.org` for BeagleBone.

* `v4.4.23-16-ev3dev-rpi` for Raspberry Pi 0/1.

* `v4.4.23-16-ev3dev-rpi2` for Raspberry Pi 2/3.

You can also find this kernel in [snapshot build][download] `2016-10-15`.

[download]: https://oss.jfrog.org/list/oss-snapshot-local/org/ev3dev/brickstrap/

For a more complete changelog, follow the link for your platform:

[EV3][ev3-changelog], [BB][bb.org-changelog], [RPi][rpi-changelog] or [RPi2][rpi2-changelog].

[ev3-changelog]: https://github.com/ev3dev/ev3dev-kpkg/blob/560058bd7d84fd2a0a086c3b24117f0fedb1dd01/ev3dev-ev3/changelog

[bb.org-changelog]: https://github.com/ev3dev/ev3dev-kpkg/blob/560058bd7d84fd2a0a086c3b24117f0fedb1dd01/ev3dev-bb.org/changelog

[rpi-changelog]: https://github.com/ev3dev/ev3dev-kpkg/blob/560058bd7d84fd2a0a086c3b24117f0fedb1dd01/ev3dev-rpi/changelog

[rpi2-changelog]: https://github.com/ev3dev/ev3dev-kpkg/blob/560058bd7d84fd2a0a086c3b24117f0fedb1dd01/ev3dev-rpi2/changelog