nrf: implement audiobusio.PDMIn

[jepler]

So far, this supports only 16kHz and 16-bit samples with a fixed gain. This is enough to support the basic functionality of e.g., sensing ambient sound levels. Stereo support is coded but untested.

Testing performed:

• all tests performed on Particle Xenon with PDM Mic Breakout
• recorded and played back short samples (using PWM Audio Out)
• adapted the "playground sound meter" program (using a NeoPixel stick board)

Additionally, @ladyada reports "tested this and it works great on my CPB"

[dhalbert]

Great, thank you! Will merge after Travis is happy.

[ladyada]

yes indeed :)

[dhalbert]

:( failed, do make translate and re-push

[dhalbert]

aargh, conflicts, you'll have to merge from upstream, then make translate

[jepler]

I'll check back on this in the morning.

[dhalbert]

Bleh, still says "missing message ID". The .po files are very re-ordered: maybe the merge didn't work out that well. Also, what version of xgettext are you using? Mine is:

$ xgettext --version
xgettext (GNU gettext-tools) 0.19.8.1
...

Maybe take the content of locale/* wholesale from upstream, and then do

make translate
make check-translate

since it's check-translate that's failing.

@tannewt Maybe we should make make check-translate be part of what make translate does, instead of being a separate target. Also tools/check-translations.py could print out which message ids are missing, which might be a debugging clue.

[jepler]

I'm on debian stretch x86_64.

jepler@babs:~$ xgettext --version
xgettext (GNU gettext-tools) 0.19.8.1
$ locale
LANG=en_US.UTF-8
LANGUAGE=
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=

[dhalbert]

@jepler Cloned your repo, did a make translate and make check-translate locally, and then pushed (permissions are set up for me to push to your repo for the PR). It passed the translate test!

[jepler]

@dhalbert thanks for cleaning up my mess! I wish I knew at what step I made a mistake. When I "make translate" at the tip of master, no errors, no grand reordering, and "check-translate" passes, so usually it works as expected. I must have made a mistake due to being in a hurry.

[dhalbert]

I'm not sure what happened, but I think the simplest explanation is just that make translate didn't get done after the merge. No worries!