Author Archives: Ryan

Zumo 32U4 Robot for RoboFest’s RoboHit competition

via Pololu Blog

We were excited to hear from the NCA Lights high school student robotics team about their recent entry in the RoboFest Michigan Championship 2017 RoboHit competition. RoboFest is a series of robotics events and competitions organized by Lawrenece Technological University. This year’s baseball-themed competition, “RoboHit”, involved hitting a ping pong ball off of a water bottle with a pencil and circling the outer edge of the arena (base running).

The NCA Lights used a Zumo 32U4 Robot Kit and two 50:1 Micro Metal Gearmotors HPCB 6V with Extended Motor Shaft as the base of their robot.

Open-source myoelectric hand prosthesis

via Pololu Blog

Alvaro Villoslada, Pololu customer, made this impressive open-source 3D-printable hand prothesis. Each finger uses a 1000:1 Micro Metal Gearmotor HP 6V with Extended Motor Shaft to wind a fishing line—acting as a tendon—onto a spool. A magnetic encoder attached to each motor enables closed-loop control, and the motors are driven by DRV8838 DC motor driver carriers. An RC hobby servo controls the thumb position. Alvaro uses a Teensy 3.1 microcontroller to monitor the encoders and control the actuators, and he built a user interface in Python for controlling the hand from a computer.

For CAD files, detailed instructions and more pictures and videos, see the Hackaday project page.

Guide utilisateur du Robot Zumo Pololu

via Pololu Blog

MCHobby, a Pololu distributor, translated the Pololu Zumo Shield for Arduino User’s Guide to French as the Guide utilisateur du Robot Zumo Pololu (2MB pdf)! They describe it in French as “Un guide complet pour assembler, utiliser et exploiter rapidement votre Robot Zumo (version 0.1)”. If you’d like to see more translations like this, please let them you know that you enjoyed it and support them by buying from their shop.

Sanyo pancake stepper motors with encoders

via Pololu Blog

We are now offering two new NEMA 17-size pancake bipolar stepper motors from Sanyo, each featuring an integrated high-resolution quadrature encoder and home channel for absolute positioning.

Stepper motor Steps per revolution Current rating (per coil) Voltage rating Resistance (per coil) Holding torque
#2279 42×31.5mm 200 1 A 5.4 V 5.4 Ω 1.9 kg-cm (26 oz-in)
#2278 42×24.5mm 200 1 A 3.5 V 3.5 Ω 800 g-cm (12 oz-in)

Side view of the SS2422-50XE100 42×31.5mm Sanyo pancake stepper motor.

Side view of the SS2421-50XE100 42×24.5mm Sanyo pancake stepper motor.

The integrated quadrature encoder operates from 5 V and has a resolution of 1000 P/R, which allows for 4000 counts per revolution (CPR) of the output shaft when counting both edges (i.e. rising and falling) of both channels (i.e. A and B). In addition to the A and B channel outputs, the encoder has a home channel, Z, that pulses once per revolution and can be used for absolute positioning. The encoder also has outputs for the inverse of A, B, and Z. A 15 cm (6″) encoder cable is included.

New 12V 1A wall power adapter

via Pololu Blog

We’ve replaced our original 12 V 1 A wall power adapter with a lighter, smaller version. This UL-listed 12 W, “wall wart”-style switching power adapter supplies up to 1 A at a regulated 12 VDC. The AC adapter works with input voltages of 100 to 240 VAC and has a 1.5 m (5 ft) DC power cord that is terminated by a center-positive, 5.5 × 2.1 mm barrel connector.

MechWarfare robot

via Pololu Blog

Forum member jwatte posted about a robot he made for the RoboGames MechWarfare 2017 competition. The goal is to build a walking robot that tries to hit an opponent’s pressure sensors with airsoft pellets or melee weapons. The robots walk around in a scaled-down cityscape field. Autonomous operation and teleoperation are allowed, but teleoperators must view the field from cameras mounted on the robot.

The mech uses a few Pololu voltage regulators: a 3.3 V, 1 A step-down regulator D24V10F3 powers a Xbee-Pro 900 XSC S3B wireless transciever and the laser pointer, a 6 V, 500 mA step-down voltage regulator D24V5F6 powers an OpenCM 9.04A robot logic board, and a adjustable step-down regulator D24V6ALV powers a 5.8 GHz wireless camera. A 250:1 Micro Metal Gearmotor LP 6V drives the plastic BB agitator that feeds the airsoft gun. The wiring harnesses used a lot of our pre-crimped wires.

For more details including a system block diagram see the forum post.