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Scary Terry Audio Servo Driver with MP3/WAV player and relay, ST-450

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0.25 LBS
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The amazing ST-450 board adds new features that we have been wanting in Scary Terry board for a long time!

The ST-450 provides all the functions of the standard Scary Terry board, such as the ST-425, but adds a build in audio player that can be triggered via a switch, motion sensor, or voltage source. In addition, a relay has been added to the board that can be used turn on/off other devices, such as a light, whenever the audio is playing. It even has a built in 3W amplifier, so all you need to add is a speaker, although we also included a line-out jack so that you can connect a higher powered amplifier if desired!

This circuit allows you to easily drive a servo for animating the jaw of your prop. Easily create a prop with that highly sought after animatronics effect.

Operates off of a 6 to 12VDC supply (9VDC @ 1000mA is recommended).

We have included a ULN2003 chip that allows you to drive devices such as relays, lamps, solenoids for pneumatics, etc. in sync with the sound you are playing.

Jumpers allow you to choose the Left or Right channel or both for the skull to follow. 

Two header pins are provided for easily attaching the LED Audio Eyes that come with the unit. They flash in sync with the sound you are playing. You can also set the LED Eyes to stay on all the time or have them flash with the sound!

Power LED shows you in a glance whether the circuit has power or not.

A free audio editor, called Audacity, can be downloaded from


Audio module specifications:

  • Supports 11172-3 and ISO13813-3 layer3 audio decoding.
  • Supports sampling rate (KHZ):8/11.025/12/16/22.05/24/32/44.1/48.
  • Supports MP3 and WAV decoding.
  • Supports FAT16 and FAT32 file system.
  • 24-bit DAC output and supports dynamic range 90dB and SNR 85dB.
  • Supports maximum 32GB micro SD.
  • Supports maximum 3000 audio files under the root directory of the storage device.
  • Supports maximum 99 folders, and each folder can stores 255 audio files.
  • Built-in a 3 watts amplifier that can direct drive a 3 watts speaker.
  • 30 levels adjustable volume.

Relay connection specifications:

  • Contact voltage: 277VAC, 30VDC Max
  • Contact current: 2A Max (the relay is rated to 5A, but the terminals on the board are 2A)
  • Wire gauge: 20-26 AWG


Please refer to the manual for complete operation capabilities and specifications.

A free audio editor, called Audacity, can be downloaded from

5 Reviews Hide Reviews Show Reviews

  • 5
    Servo board

    Posted by Tyson on 30th Jun 2023

    Work perfectly 100 would buy again for future projects

  • 5
    I lover this board!!!

    Posted by David Swaner on 16th Sep 2021

    I'm so glad I found This board effortless does everything that I was trying to do with a raspberry pi. It's very customizable and easy to use, and if helping me take my Halloween projects to the next level.

  • 5

    Posted by Dene Holden on 20th Apr 2021

    Saved me time and money

  • 4
    Scary Terry Audio Servo Driver with MP3/WAV player and relay, ST-450

    Posted by Randy on 26th Sep 2019

    First let me start with, I love this board. It's well built, functions as advertised. Very useful.With that said, the only reason I didn't give it 4 stars is the limited capabilities of the MP3 Player. There is nothing wrong with it, it functions well, just as it is described. What would make it perfect would be a method of making the MP3/ files selectable. Being able to call a specific track number would make this perfect. Other than that limitation, this board is perfect for general animatronics. Like I said before, I love this board. I have recommended and will continue to.

  • 5
    Scary Terry Audio Servo Driver - ST-450

    Posted by Leigh Woodall on 5th Jul 2019

    I purchased 2 of these boards to create a talking cow and horse. They are working exactly as planned. This company is a pleasure to deal with. They ship quickly and are very responsive to questions about their products.

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