SparkFun
SparkFun Servo Trigger
The SparkFun Servo Trigger is a compact robotics board that simplifies control of hobby RC servo motors — no programming required. When an external switch or...
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The SparkFun Servo Trigger is a compact robotics board that simplifies control of hobby RC servo motors — no programming required. When an external switch or logic signal changes state, the board tells an attached servo to move from position A to position B.
Simply connect a hobby servo and a switch, then adjust the three on-board potentiometers to set the start position, end position, and transition time. The board is designed for easy daisy chaining — connect the VCC and GND pads on adjacent boards to run multiple servos from a single power source.
Key Features
- No Programming Required – Configure everything with three potentiometers
- Three Control Potentiometers – A (start position), B (end position), T (transition time)
- ATtiny84 Microcontroller – Handles all servo control logic on-board
- Configurable Input Polarity – Works with normally-open or normally-closed switches
- Configurable Response Mode – Multiple operating modes available via the hookup guide
- Daisy Chainable – Connect multiple boards via shared VCC and GND pads
- ISP Header – Reprogrammable via standard ISP programming pins
- Low Current Draw – Approximately 5 mA at 5 V (excluding servo)
Specifications
- Recommended Voltage: 5 V DC
- Maximum Voltage: 5.5 V DC
- Current Draw: ~5 mA (board only)
- Servo Compatibility: Analog hobby servos
Ideal For
- Animatronics and props
- Automated doors, gates, and latches
- Robotics projects without a microcontroller
- Interactive displays and exhibits
Resources
Jargon buster
Plain-language definitions for the technical terms used above.
- DC
- DC means direct current, where electricity flows in one constant direction, as supplied by batteries, USB ports and many plug-pack power supplies. When a product specifies DC, it runs from a DC supply rather than mains AC, so you need to provide the correct voltage and polarity.
- GND
- GND is the ground or reference connection (0 V) for a circuit. When connecting two devices together, their grounds must be joined so both agree on what counts as a low or high signal.
- ISP
- In electronics, ISP usually means In-System Programming, a way to load firmware onto a microcontroller while it stays on the board (often via an ICSP header), or an Image Signal Processor, hardware that turns raw camera sensor data into usable images and offloads the main CPU. The surrounding context shows which meaning applies.
- microcontroller
- A microcontroller is a small computer on a single chip that runs a stored program and controls connected inputs and outputs such as buttons, sensors, displays and communication interfaces. In a device built around one, it is the part that executes the code and coordinates the device's behaviour.
- servo
- A servo is a motor with built-in position control, usually told to move to a specific angle by a control signal. It matters when you need repeatable movement, such as steering, arms, flaps, or linkages, rather than continuous spinning.
- VCC
- VCC is the positive power-supply connection on a chip or module. Connecting it to the correct supply voltage is needed for the part to power on and helps avoid damaging the electronics.
Find this product in
Brands
Robotics & Motion
SparkFun Servo Trigger Schematic
Schematic · 116.0 KB · Click any page to view full size
Servo Trigger IC Datasheet
Datasheet · 4.4 MB · Click any page to view full size
Supplier page — sparkfun.com
Supplier Description · 646.1 KB · Click any page to view full size
Resources & Downloads
Guides, code examples, and more
Source Code
Open-source libraries, firmware & example projects for this product
Board that actuates a servo based on switch closures, logic pulses, etc.
92e9792
over 6 years ago
· 31 commits
- Docs Revision from collaborator and checklists over 11 years ago
- Firmware Adding FSM comments to C source over 11 years ago
- Hardware Updating description of mode jumper. almost 11 years ago
- Production Updating README, fixing directory names over 11 years ago
- .gitattributes Initial Commit almost 12 years ago
- .gitignore Adding makefile, some proofreading. over 11 years ago
- LICENSE.md Initial Commit almost 12 years ago
- README.md Update README.md over 6 years ago
Related Tutorials
Free guides on learn.littlebird.com.au