NEW!!!   Software version 1.4 is available (Oktober 20 2022).

Note there are only two files, options like GPS and/or temperature sensor or battery monitor chip are automatically detected.


This is Cor Berrevoets domain. I am always amazed how well he is able to implements new ideas that come up.


This is the initial release 1.0 version from 2020

Shortly after we had a 1.0x experimental version which is very stable. There is an added playback mode that allows you the play 192KHz sample rate files as if you are receiving them. It gels you to get a good look and feel of different ultrasonic sounds.

Early 2021 there was a change to long filenames, added Guano metadata, the possibility to add a GPS and temperature sensor. This still is a development release 1.1dev 10april 2021 and it also has the possibility to control the display backlight. Controlling the backlight needs a small hardware modification. After you made that modification you can not return to the 1.0 software versions.

Version 1.2 22may2012 is now replaced by version 1.3 which has some bugs fixed so we are now on version 1.31

The software files can be uploaded to the Teensy using the update tools (Windows XP and later) on Linux you can use the same procedure if you have Arduino and Teensyduino installed.

Now that version 1.31 is no longer needed I will remove these files form the website but keep the om my google drive.


So here we have software version 1.4.

The update addresses quite a few small improvements in functions most users will probably not notice.

The biggest changes are that the hardware options are automatically detected. There are just two files, one for the Teensy 3.6 based version and one for the Teensy 4.1 based versions. Before we had separate files for detectors with added GPS or Temperature sensor or both.

There is a battery charge status indication on the display (current PCB’s need modification(v0.7)).

The other most noticeable is the removed noise in the stored power-spectrum. (shown on playback on the detector itself). This spectrum is a stacked power spectrum so it shows the narrow peak around the strongest signals in the recording. It helps to quickly determine odd recording within the known species. On Cor's github there is a more detailed description of the changes.


Here is an example or the display during playback.

In the previous version we had a pile of noise around 23Khz in every powerspectrum.


You can also see the battery charge status display. It looks like four bars showing 25/50/75/100 percent but if you look closer it are actually individual lines that build the four bars.


If the charge status is below 50% the color changes to yellow, below 25% it changes to red.  We have not tested how accurate this fuel gauge is and the rest time to uses also depends on the used lithium cell.

It is wise to start the detector in default settings (pres left button at power-on) after updating to a new software version.

Be careful, Teensy 3.6 and 4.1 use their own version software. If you accidental load the wrong software you can not load the right software unless you press the reset button on the Teensy! The software "teensy_reboot" will not work. This involves opening the detector, remove the display and press the small switch on the Teensy at the moment you would have normally used teensy_reset.exe

Keep in mind that the audiobuffer can hold old samples when you change samplerate and press record quickly after changing. Also different samplerates for normal uses and autorecord can end up having a funny samplerate in the first recording. To prevent that use the same sample rate for normal use and autorecord or discard the first recording after changing from and to autorecord. 

Please use the same sample rate in "Startup defaults" and "Auto recording" settings page when using autorecord with deepsleep.

Teensybat 1.4 For Teensy 3.6
Archive – 363,3 KB 33 downloads
Teensybat 1.4 For Teensy 4.1
Archive – 322,3 KB 51 downloads

The hex files in these zip files have debugging off, and the T4.1 versions need to have PSRAM in the Teensy board.

More HEX files can be found at:

These also will include some with debugging enabled for troubleshooting purposes.

Update Tools
Archive – 4,1 MB 579 downloads


Instructions for Windows XP and higher.

STEP 1 unzip all the files on the update tools and software zip file in one folder.

Your computer needs the Teensy serial driver, windons10 has one built in, on older systems first install the serial driver.
Simply run serial_install.exe on older windows versions by double click and follow the instructions (Yes OK Next, whatever)

Now, plug-in the Teensy micro USB (right side of the detector) and connect to your computer, the computer will find a new device (Teensy Serial). Finish the installation of the driver by clicking Next, OK, Yes or whatever button comes up.

Next run Teensy.exe

Select File and choose the xxxxxxxxx.hex file (please be ware of Teensy 3.6 and 4.1 difference) 

Click the dark green button so it lights up and you can read "Auto" (might work without auto)

now run reboot.exe (if you can reach the small switch on the Teensy you can press that instead)

The Teensy should reboot load the software and start up again. This should only take seconds.

STEP 8 Disconnect the USB connector and use the TeensyBat detector.

There is a small chance the reboot will make the computer find an other USB HID driver and the upload will abort.
Simply try again, I am sure it will work the next time.

If your detector has any problem try a “factory reset” first by holding the left button and turn on the detector. Release the button as soon as “Resetting to defaults”appears.



Source code


If you do like to compile the software yourself you can use Arduino or PlatformIO in combination with Teensyduino to work on the source and compile the software.

You can find the code made by Cor Berrevoets on his Github page.

Source version 1.0 (initial release)

Source version 1.1dev (winter 2020/2021)

Source version 1.2 (May 2021)

Source version 1.3 (September 2021) compiling needs PlatformIO from now on

Source version 1.4 (Oktober 2022) 

Here are files with debugging enabled, just in case you run into a problem and we need some more information via USB serial port/terminal. The zip file contains 3 files for both T3.6 and T4.1 and T4.1 without PSRAM

TeensyBat 1.4 For Teensy 4.1 And Teensy 3.6 DEBUG
Archive – 1,0 MB 25 downloads