SparkFun Servo Trigger

Simple, Code-Free Servo Control

The SparkFun Servo Trigger is designed for one purpose: to make controlling hobby RC servos easy for everyone. It's the perfect solution for artists, prop makers, and hobbyists who need to create motion without the hassle of writing or debugging code. This board acts as a simple-to-configure "brain," moving a servo between two set positions in response to an external trigger.

Intuitive Dial-Based Setup

Operation is incredibly straightforward. Connect your servo, a power source (5.5V max), and a trigger—like a button, switch, or logic signal. The board features three on-board potentiometers for adjustment:

• Position "A": Use this pot to set the servo's "home" position (when the switch is open).
• Position "B": Use this pot to set the servo's "activated" position (when the switch is closed).
• Time "T": This pot controls the ramp time, allowing you to set the speed of the transition. You can create anything from a lightning-fast "snap" to a slow, smooth sweep.

Technical Details & Advanced Use

At its heart, an Atmel ATTiny84 microcontroller runs a small program to manage the servo control. The board itself is highly efficient, drawing only about 5mA at 5V (Note: the servo's current draw will be much higher). For larger installations, the Servo Trigger is designed to be easily daisy-chained by connecting the VCC and GND pads of adjacent boards.

While it's powerful in its default A-B mode, the Servo Trigger has even more capabilities. Be sure to check out the Hookup Guide in the Documents section for advanced tips, configurations, and hidden modes!

Note: This idea originally came from our friend in the Oakland area, CTP. If you see him, please give him a high-five for us.

• Schematic
• Eagle Files
• Hookup Guide
• Datasheet (ATtiny84)
• GitHub