TeensyBat diy batdetector


Welcome to my Teensybat page. I am Edwin Houwertjes an enthusiastic electronics hobbyist working with the TeensyBat detector for a few years now.

I hope the help you build a detector like this TeensyBat using the information on this website.

New software version 1.3 is released.

(A small bug has been found, the software files that fix this were updated oktober 09 2021)

New Teensybat hardware version is coming but will take some time, old version boards and kits are sold out you might have to get your own boards made or wait for the new version.


Work on the printed circuit board is well on its way, but not quite finished. The plan is to have a PCB made on which the audio board is already intergrated and all SMD parts are already in place. A charger circuit is on the pcb so one only needs to solder headers, jackplugs, encoders and switches and connect a lithium battery. The lithium-ion battery will power the Teensy directly so there is no more noisy step-up circuit.

This will mean there is a lot less to solder but the PCB will be more expensive. Since this is only affordable with larger numbers I have to be sure the PCB is prefect. (I cant afford small numbers or throw away large numbers op PCB's with problems).


Why Teensy 4.1? Well a huge advantage is the extra memory we can mount. It will give you a nice prerecord buffer that allows you to store about 4 seconds of sound that you just heard.


Bat detector that shows received sound. od a common pipistrelle.

Keywords: bat, detector, batdetector, vleermuis, vleermuisdetector, teensy, time expansion, heterodyne, frequency division, frequentiedeler, ultrasoon, spu0410lr5h, spu0410lr5h-qb, zelfbouw, diy, homebrew, spectrogram, waterval, waterfall, classify,

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Edwin Houwertjes
2 days ago

Normally I do not write here but answering Thomas gives some idea about the developments.

Teensy 4.1 version boards are ordered, but production takes some time.
The Audioboard is still used. It provides extra gain setting and is also usefull for playback (connecting headphones) we will be using the audio board but it is integrated on the main board.
We do uses extra memory that can be soldered directly to the Teensy it is not used to help reducing "writing sounds" I helps us store sounds that already passed a few seconds ago.

The noises of the SD card writing can be reduced by separating Vin(Teensy) and input of te 3.3V LDO(IC2), and give each their own RC filter (ad an extra R10/C10 circuit)

3 days ago

I am quite happy with my teensyBat based on v0.2a. Would it be possible to come up with a new hardware version based on teensy 4.1 and without the need for the extra audio board (built-in ADCs only)? This would reduce the cost.
Would it also be possible to "record" the signal into a buffer for some time and save it later to the SD card? This would avoid noise coupling into the signal from SD card write operations.

Thank you so much for your effort to make this project available for a bat enthusiast like me.

Ap Bruinenberg
22 days ago

Prachtig project dat zeer goede resultaten oplevert, dank voor de creators !

a month ago

In 2019 heb ik een compleet werkende detector van U gekocht. Ik ben daar zeer tevreden over. Ik kijk met belangstelling uit naar de 4.1 update. Ik zou graag een kit, pcb of onderdelen willen bestellen als het beschikbaar is.

Tom Kreyche
a month ago

Dear TeensyBat team - great work! I look forward to your new hardware release and will purchase a kit or circuit board or parts when it's available.

Tom Kreyche KF7NOP, Seattle Washington USA

pieter smit
a month ago

Just loaded the new 1.3 software, went flawless into the Teensy. Its fantastic that image now continues while recording. And the auto gain (plus downward expanded gain reach) will hopefully solve the problem that bats flying close by, overpowered the input channel. Thanks for all the good work!

Jan Thyregod
a month ago

Facinating project and I would like to build one for a friend. Please contact me as I cant mail you once the new PCBs are available. Br Jan

Bartle de Leeuw
4 months ago

ik zounhier graag wat meer over willen weten

Edwin Houwertjes
5 months ago

Just for fun we have some place to write any comments. If you have any technical question mail me. In Dutch or English is fine.