Thanks for posting your findings on this topic.
Plenty of the Audio Injector boards on local Amazon so I bought four in hopes
that your tests would prove favorable. Thanks for the favorable results!
I haven’t worked with a Raspberry Pi before but have a new CanaKit RPi 3 and
though I would use it with the Audio Injector module. Then I saw your message
indicating disinclination toward RPi 3 power dissipation (from unused built-in
Bluetooth and WiFi). I had guessed that the RPi would be used to enable a
wireless connection between antenna and laptop/PC, which raises a question (if
you have a moment): for a backyard-antenna-to-indoor-laptop application or for
a portable field-test application, what type of interface would be used between
an outdoor RPi 2 and an indoor laptop or portable-field-test laptop? (or am I
on the wrong track; should I be thinking of Audio Injector plus RPi 2as an
unattended datalogger rather than a real-time interface between VLF loop and
From: [email protected]
[mailto:[email protected]] On Behalf Of Paul Nicholson
Sent: Wednesday, February 15, 2017 5:02 PM
To: [email protected]
Subject: Re: LF: Raspberry Pi sound interface that works
Another update to EbSynth, now at version 0.7a
Now compensates properly for changing delay of the output buffer as the sample
rate wanders. A temperature change that previously produced a 30 degree output
change now only affects the phase by about 0.3 degrees. The residual is a 2nd
order effect proportional to the rate of change of sample rate.
I've noticed a couple of sound card input overruns on the RPi when the CPUs are
very busy. 0.7a assigns itself a real-time scheduling policy at high priority.
It remains to be seen if that fixes the overruns.