Wildlife Acoustics Blog

How to get the most out of your SM2+ recorder

How to get the most out of your SM2+ recorder

Hello again All,

So, pop quiz, what firmware revision are your SM2s running? Right now? Do you know where your firmware is?

All joking aside, keeping your firmware updated is one of the easiest ways to make sure that your SM2 recorders are running up to snuff. Every time our engineering staff releases a new version, you can be assured that bugs will be fixed and (maybe) a few new features will be added. Let’s take a look one of the great things that the latest firmware revision as of this writing (3.2.5) holds for you: the SD Card Speed Test.

Also, as always, the latest firmware installs a number of cumulative bug fixes. A complete record of these can be found in our firmware release notes.

The SD Card Speed Test utility is especially important for our SM2BAT+ customers. Some SD cards, when recording in the higher sampling frequencies, can drop data occasionally in a predictable pattern. This occurs as the card attempts to save the incoming data, while being unable to keep up with the fast sampling frequencies. This flaw varies from SD card manufacturer, and it can even change from batch to batch from the same maker! To compensate for this issue, Wildlife Acoustics has built a test into the firmware that can predict the rate that this “glitching” can occur.

To access this utility, open the main menu by pressing the SELECT button after turning the SM2 on. Then, insert the card that you want to test into SD Card Slot A (the leftmost one). Scroll down to UTILITIES and hit SELECT again. Then scroll down to the line that reads SPEED TEST A:. After hitting SELECT again, you’ll see a screen that asks you to wait and also tells you the basic function of the test. After about a minute, a list of sampling frequencies with a bunch of numbers next to them will pop up. Look for the sampling frequency that you plan on using and observe the numbers to the right of it. The first number shows when (in seconds) the card will have its first “hiccup” after a recording is started. The second number is the time (again in seconds) until the next predicted “hiccup”. This is useful, especially in ultrasonic recording, because you’ll be able to see if your card will never glitch, glitch infrequently, or glitch with a constant pattern.

For example, if you inserted your trusty 32GB card that you always use when you record at 192 kHz, and you got a result of 0/0 during the speed test, then your card is glitch-free! Congrats! You might also get a result of 6/99. This would signify that your card will probably glitch at the sixth second of your recording, then again at least 99 seconds in (or maybe never again). This is doable, as you can allow for the possibility that a little data may be dropped in a given recording period.

However, if you run a card through the test and the result is something like 2/4 or 5/10, then it might be best not to use that card. This shows that the card is predicted to glitch every 2 seconds and every 5 seconds, respectively. This would obviously be a problem if you’re recording for any long period of time.

One of the best things about the SM2 platform is that you can use any SD card (given that it’s formatted properly) to record your call data. The speed test is a great tool to make sure that the cards that you are using will perform properly and reliably. However, if you find yourself in need of new SD cards, we carry a variety of sizes in our online store. All of the cards that we ship to our customers are tested, formatted, and ready to go when they arrive at your door.

I hope that I’ve been able to illuminate one of our new firmware features for you. We’re very happy with the utility, and we hope that it will ensure your recordings come out clear and ready for analysis. If you have any questions about the Speed Test, or anything else to do with our product line, feel free to contact our support staff at support2013@wildlifeacoustics.com. And, if you have a question that you would like me to answer here on the blog, just drop me a line at Aubrey@wildlifeacoustics.com with Tech’s Desk in the subject line.

Until we meet again: good luck, and happy science!

Wildlife Acoustics is proud to support wildlife conservation efforts

Merlin Tuttle's Bat Conservation Bat Conservation International Bat Conservation Trust Wildlife Habitat Counsil