Fingerprint Sensor AS608 - A Beginner's Guide
One touch can replace keys. This project uses an optical fingerprint sensor to enroll users and then grant access with a quick scan.
read tutorial →
Add Feedback to Your Gearmotor with Romi Encoder Pair Kit, 12 CPR, 3.5-18V
The Romi Encoder Pair Kit, 12 CPR, 3.5-18V adds position and speed feedback to matching Pololu motors so your project can move from open-loop control to measured motion.
It is useful for odometry, wheel speed control, closed-loop drive systems, and motion experiments.
Why you'll love it
- 12 counts/rev of motor shaft: counting both edges of both channels gives 12 CPR (about 1440 counts per wheel revolution on the Romi)
- Wide supply range: sensors run on 3.5V to 18V for flexible robot power setups
- Microcontroller-ready outputs: A and B are open-drain digital signals —pull up to your logic voltage (3.3V or 5V)
- Compact & chassis-friendly: designed to fit neatly on the back of Romi motors without extending past the shaft
- Closed-loop speed control (PID)
- Odometry / distance tracking
What you can build
Use it for wheel odometry, wheel-speed feedback, closed-loop speed control, and motion experiments with supported Pololu motors.
Compare encoder kit options
| Kit | Resolution | Fits | Voltage |
|---|---|---|---|
| Encoder Kit for 20D mm Metal Gearmotors, 20 CPR, 2.7-18V | 20 CPR | 20D metal gearmotors | 2.7-18 V |
| Encoder Kit for Micro Metal Gearmotors, 12 CPR, 2.7-18V | 12 CPR | Micro metal gearmotors | 2.7-18 V |
| Encoder Kit for Mini Plastic Gearmotors, 12 CPR, 2.7-18V | 12 CPR | Mini plastic gearmotors | 2.7-18 V |
| Encoder Kit with Side-Entry Connector for Micro Metal Gearmotors, 12 CPR, 2.7-18V | 12 CPR | Micro metal gearmotors | 2.7-18 V |
| Romi Encoder Pair Kit, 12 CPR, 3.5-18V | 12 CPR | Romi motors | 3.5-18 V |
Technical specifications
| Product | Romi Encoder Pair Kit, 12 CPR, 3.5-18V |
|---|---|
| Brand | Pololu |
| Category | Encoder Upgrade Kit |
| Operating Voltage | 3.5-18 V |
| Encoder Resolution | 12 CPR |
| Support | Official Pololu product search and support resources linked below |
Official resources
Find this product on Pololu | Pololu support and resources
What’s in the box
1 × Romi Encoder Pair Kit, 12 CPR, 3.5-18V
Frequently Asked Questions
Will this work with Arduino or similar boards?
Yes, with the correct supply voltage and interface wiring for the specific product.
Yes, with the correct supply voltage and interface wiring for the specific product.
Is this good for robotics projects?
Yes. Pololu parts are widely used in robots, motion systems, and embedded prototypes.
Yes. Pololu parts are widely used in robots, motion systems, and embedded prototypes.
Where can I find official docs?
The description below links to official Pololu search and support resources for this item.
The description below links to official Pololu search and support resources for this item.
Manila stock. Order before 16:00 PHT, ships today via J&T or LBC. Provincial: 1–3 working days.
Schools / class POs: we accept Purchase Orders for accredited schools and universities. contact us with your PO details.
Returns: 7-day inspection window for DOA units. Email proof of issue and we ship a replacement.
Compatibility & downloads
// downloads
- Schematic pdf
Customers also bought
Build with this board
Thumb Joystick - A Beginner's Guide
Wire a joystick to your Arduino, read X/Y, then print UP / DOWN / LEFT / RIGHT to the serial monitor.
read tutorial →Motor Drive (BTS7960 43A) - A Beginner's Guide
Bench-test a 43 A motor driver before wiring the full project. Catches weak power, mis-pinning, and dead boards before they cost you time.
read tutorial →Raspberry Pi Pico (RP2040) - A Beginner's Guide
Coming from UNO and the Pico won't show a COM port? Here's the BOOTSEL trick, the driver fix, and the first sketch that actually works.
read tutorial →Notes from the bench
Ask the community
Project Showcase — show what you built
Share what you built. Photos, BOM, what worked, what didn't.
view thread →How to ask a good question (and actually get answers)
Symptom + what you tried + clear photo = answers within hours.
view thread →ESP32 brownout when wiring a sensor — fixes that worked
Brownout reset when adding a sensor? Notes on supply decoupling and GPIO checks.
view thread →First Arduino — sketch upload error, what to try?
Upload failing on your first Uno? Driver, COM port, board match — checklist inside.
view thread →