Software version 1.31 is available (april 16 2022), this is fixes 3 bugs that were in the initial version 1.3

(Sample rate issue when both active and autorecord were set below default, leap-year error for gps, 384Khz not available/hangs)


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.



So, maybe you did not notice, but there was a small gap in the recordings using the 1.2 version of the software, this is fixed now, and also some other improvements have been made.  We now also have the waterfall and time-expansion available during recording. We also have additional filtering options, audomatic micgain control and a "deepsleep function that allows the detector to wake up during the night to start automated (triggered) recording to save battery power during the day. A few descriptions of the features are here in the PJRC forum.

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

Teensybat 1.31 for Teensy 3.6 based version
Archive – 1,3 MB 143 downloads
Teensybat 1.31 for Teensy 4.1 based version
Archive – 1,2 MB 202 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 include some with debugging enabled for troubleshooting purposes.

Update Tools
Archive – 4,1 MB 519 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 doucble 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 (*)

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


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.

Teensybat 1.31 Teensy 3.6 Debugging Enabled
Archive – 1,4 MB 81 downloads
Teensybat 1.31 Teensy 4.1 Debugging Enabeld
Archive – 1,5 MB 99 downloads