Posts by Ryan (Page 2)

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MechWarfare robot

Posted by Ryan on 5 May 2017

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.

FEETECH Mini Servo FT1117M

Posted by Ryan on 4 May 2017
Tags: new products

We added the FEETECH Mini Servo FT1117M to our expanding RC servo selection.This miniature-sized servo has a stall torque of 50 oz-in (3.5 kg-cm) and a speed of 0.11 sec/60° at 6 V. The pinion gear is plastic, but the rest of the gear train consists of all metal gears, allowing this servo to deliver the kind of speed and torque typically associated with larger servos.

Comparison to the Power HD 1711MG mini servo

This servo is a lower-cost alternative to the 1711MG from Power HD, which has nearly identical dimensions and performance. The two servos should be generally interchangeable for most applications. The picture below shows both the FT1117M and the 1711MG side by side:

Expect more new FEETECH servos in the coming weeks!

RoboClaw 2x60A Motor Controller (V6)

Posted by Ryan on 18 April 2017
Tags: new products

The RoboClaw 2x60A motor controller (V5) we’ve been carrying has been replaced by the new RoboClaw 2x60A Motor Controller (V6). This powerful motor controller can drive two brushed DC motors with 60 A continuously at voltages from 6 V to 34 V, and it allows for peak currents up to 120 A. Version six adds a protective aluminum plate to the board bottom and ports for connecting optional cooling fans that are controlled based on the board temperature.

RoboClaw 2×60A Motor Controller (V6) and RoboClaw 2×60AHV Motor Controller (60VDC), bottom view.

The RoboClaw motor controllers from Ion Motion Control can control a pair of brushed DC motors using USB serial, TTL serial, RC, or analog inputs. Integrated dual quadrature decoders make it easy to create a closed-loop speed control system, or analog feedback can be used for position control.

For more information, see the product page.

Wall Power Adapter: 5.25VDC, 2.4A, 20AWG MicroUSB Cable

Posted by Ryan on 17 April 2017
Tags: new products

We’ve added this Micro-USB wall adapter to our catalog. It can supply up to 2.4 A at 5.25 VDC (the USB specification’s maximum bus voltage), allowing for voltage drop due to power draw when powering 5 V electronics. It features a 1.5 m to 1.8 m (5 ft to 6 ft) DC power cord with 20 AWG wires that is terminated by a USB Micro-B connector, which makes it great for powering devices like a Raspberry Pi (especially newer Raspberry Pi models, like the Pi 3, which can draw a lot of current!).

Raspberry Pi connected to a Wall Power Adapter: 5.25VDC, 2.5A, 20AWG MicroUSB Cable.

For more details, see the product page.

Verbal Machines VM-CLAP1 Hand Clap Sensor

Posted by Ryan on 14 April 2017
Tags: new products

Don’t hold your applause: we are now offering the Verbal Machines VM-CLAP1 Hand Clap Sensor! This board is a low-power, microprocessor-based audio sensor that can detect hand claps or finger snaps while ignoring background noises such as human speech or music. It operates from 2.5 V to 5.5 V and offers a simple interface: when a clap or snap is detected, the output pin goes low for 40 ms, and the integrated blue LED lights up.

Balancing robot with stepper motors

Posted by Ryan on 10 April 2017

One of our customers built this six-foot tall balancing robot. The main microcontroller is a Teensy 3.6, and the stepper motors are driven by ST-M5045 drivers. For its drive train it uses two 3 A stepper motors connected to Pololu 90 mm wheels via Pololu universal aluminum mounting hubs.

Here’s what they have to say about using stepper motors:

I used stepper motors to take advantage of high torque at low RPM and zero backlash. This allows very steady stand-still performance. But dealing with the stepper-induced mechanical vibration was an issue. This was mostly solved with analog filters on the IMU and with an Extended Kalman Filter in software.

Additional description and pictures are available on the project page.

Arduino library for Sharp distance sensors

Posted by Ryan on 6 April 2017

Julien de la Bruère-Terreault (also known as DrGFreeman on the Pololu Forum, creator of the Custom Mini Sumo robot and the Romi and Raspberry Pi robot shared on this blog) made “SharpDistSensor” an Arduino library for analog Sharp distance sensors. If you’re running a recent version of the Arduino IDE, you can install it with the Library Manager. The library reads the sensor’s analog voltage output, filters the data, and converts it to a distance measurement. By default it is calibrated to work with the Sharp GP2Y0A60SZLF analog distance sensor 10-150cm 5V, but you can calibrate it to other analog Sharp distance sensors (if you can fit a power function or a fifth order polynomial to the voltage vs distance response of your sensor). Pull requests are welcome for supporting other Sharp distance sensor models!

The readme, library code, and example sketches are available in the GitHub repository.

Custom laser cutting for retro-gaming TV enclosure

Posted by Ryan on 5 April 2017

One of our customers used our custom laser cutting service to cut the birch plywood panels for his retro-gaming TV system that he sells on Etsy. The birch panels are stained with shellac. The system runs on a Raspberry Pi 3 Model B, to which you can connect (not-included) controllers with Bluetooth or USB. The Raspberry Pi’s Ethernet port, SD card slot, and 4 USB ports are accessible in the back.

Semi-autonomous 14-DOF quadrupeds using Mini Maestro

Posted by Ryan on 4 April 2017

Customer Lujing Cen’s team built two semi-autonomous 14-DOF quadrupeds using Mini Maestros for their high school class project at the California Academy of Mathematics and Science. The project syllabus includes making two separate robot designs and three total robots that work together. These quadrupeds were the “pack robots” described in the syllabus. An 18-channel Mini Maestro USB servo controller controls the twelve leg and two head servos. The project code includes a rewrite of Pololu’s Maestro C# USB SDK library in Python. The robot uses a camera and an RFID scanner to track its targets.

For the complete project documentation including more pictures and videos, see their GitHub project page. Lujing also posted about it on the Pololu Forum.

FEETECH High-Torque Servo FS5115M

Posted by Ryan on 31 March 2017
Tags: new products

We added the FEETECH High-Torque Servo FS5115M to our expanding RC servo selection. This standard-size analog servo has a stall torque of 215 oz-in (15.5 kg-cm) at 6 V, more than twice the torque of our standard-size servos with plastic gears thanks to its powerful motor and all-metal gear train. This higher torque requires more power: this servo can draw bursts of current in excess of 3 A at 6 V, about three times higher than a typical standard-size servo. The output shaft is supported by two ball bearings for reduced friction.

Comparison to the Power HD 1501MG high-torque servo

This servo is a lower-cost alternative to the 1501MG from Power HD, which has nearly identical dimensions and similar performance. The two servos should be generally interchangeable for most applications. The picture below shows both the FS5115M and the 1501MG side by side:

Expect more new FEETECH servos in the coming weeks!

New Products

Motoron M2T550 Dual I²C Motor Controller (Header Pins Soldered)
6V Step-Up/Step-Down Voltage Regulator S8V9F6
Zumo 2040 Main Board
VL53L8CX Time-of-Flight 8×8-Zone Distance Sensor Carrier with Voltage Regulators, 400cm Max
75:1 Micro Metal Gearmotor HP 6V with 12 CPR Encoder, Back Connector
3.3V, 2.5A Step-Up/Step-Down Voltage Regulator S13V25F3
150:1 Micro Metal Gearmotor MP 6V with 12 CPR Encoder, Side Connector
MinIMU-9 v6 Gyro, Accelerometer, and Compass (LSM6DSO and LIS3MDL Carrier)
75:1 Micro Metal Gearmotor HP 6V with 12 CPR Encoder, Side Connector
298:1 Micro Metal Gearmotor LP 6V with 12 CPR Encoder, Back Connector
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