Posts by Brandon

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Automated ball path contraption for the holiday season

Posted by Brandon on 3 December 2014

Bruno Schneider posted the above video on our forum that showcases an automated ball path machine he made for last year’s advent season with his brother and father. The contraption uses a 24-channel Mini Maestro and is displayed in the window of his mother’s sewing shop. The machine is fun and impressive by itself, but the video (with accompanying sound effects) makes the project even more entertaining.

If you make or have made any festive projects using the Maestro or any of our other products, we would love to see them! You can post them in the comments below or in the Share Your Projects section of our forum, which is also a great place to browse for inspiration or ideas for a new project.

ToyCollect: A robot that collects toys from hard-to-reach places

Posted by Brandon on 19 November 2014
ToyCollect: A robot that collects toys from hard-to-reach places

The people at Seewald Solutions posted about their Raspberry Pi-based robot they call ToyCollect. Inspired by the creator’s daughter, who hides her toys under the couch, the robot is controlled via Android and can be driven under the couch to allow the user to view the hidden toys via a Raspberry Pi camera module and retrieve them. Along with a Raspberry Pi, the ToyCollect robot uses a Zumo Chassis Kit, 100:1 Micro Metal Gearmotors HP, Qik 2sv1 Dual Serial Motor Controller, and a Zumo blade to push the toys. The video below shows the robot in action (in German; subtitles available):

For more information, including the source code and instructions for building your own ToyCollect robot, see the ToyCollect post on the Seewald Solutions website.

New products: Brackets for mini plastic gearmotors

Posted by Brandon on 14 November 2014
Tags: new products

Our mini plastic gearmotors make great low-cost actuators for small robots, but they have one major shortcoming: they are not easy to mount (the offset versions have just one mounting hole and the 90° versions don’t have any). Well, today I am pleased to announce that we now have two mounting solutions!

Mini Plastic Gearmotor Bracket Pair – Wide.
Mini Plastic Gearmotor Bracket Pair – Tall.

These new plastic brackets, available in a wide version and a tall version, are designed specifically for our mini plastic gearmotors, with internal ridges that fit into recessed features on the gearmotors to hold them securely in place. Both brackets are compatible with all of our mini plastic gearmotors, and the two versions allow for different mounting orientations, some of which can be seen in the pictures below:

In some orientations, features of the mini plastic gearmotor cases prevent them from being flush with a flat mounting surface. To address this, we include a spacer plate with each bracket that fits between the gearmotor and the mounting surface in these orientations, keeping the motor level. If you look closely at the pictures above, you can see the spacer plate being used in three of them.

These new brackets are sold in pairs along with mounting hardware (two M3 screws and nuts per bracket).

See the product pages for additional information:

New products: Brackets for Sharp GP2Y0A02, GP2Y0A21, and GP2Y0A41 distance sensors

Posted by Brandon on 6 November 2014
Tags: new products
New products: Brackets for Sharp GP2Y0A02, GP2Y0A21, and GP2Y0A41 distance sensors

Our new stamped aluminum L-brackets are specifically designed for Sharp’s popular analog GP2Y0A02, GP2Y0A21, and GP2Y0A41 distance sensors, making it easy to mount them to your project in a variety of ways. The brackets are made of 0.8mm-thick aluminum, so they are light and bendable by hand if your application calls for something other than their default 90° angle, yet they are rigid enough to hold their position while in use.

These new brackets are sold in pairs and are available in three different versions: compact perpendicular and parallel versions, and a slightly larger but more versatile multi-option version.

The appropriate bracket for your project depends on the specifics of how you would like to mount it. For example, if you want a low-profile installation on a horizontal surface, the parallel bracket (pictured above on the left) is a good choice. For a low-profile installation off of a vertical surface, the perpendicular bracket (pictured above on the right) might be most appropriate. The multi-option bracket (pictured above in the center) allows the sensor to be mounted to either face, so it supports both perpendicular and parallel orientations, and the long slots offer a lot of flexibility in sensor placement relative to the mounting surface.

See the product pages for additional information:

New products: Six new Mini Plastic Gearmotors

Posted by Brandon on 16 October 2014
Tags: new products
New products: Six new Mini Plastic Gearmotors

Our family of Mini Plastic Gearmotors is growing! We have added HP versions with more powerful motors for increased torque and speed, and we are now carrying versions with extended motor shafts intended for use with custom encoders for motor speed and position feedback. (These extended-shaft versions are not compatible with the magnetic encoders we just released for our Micro Metal Gearmotors; we will have a similar encoder solution for these plastic gearmotors at some point, but for now we are offering them for people who want to make their own encoders.) The following table shows the current state of our Mini Plastic Gearmotor family:

Motor Type Stall
Current
@ 4.5 V
No-Load
Speed
@ 4.5 V
Stall Torque
@ 4.5 V


90° output


90° output + motor shaft


offset output


offset output + motor shaft
high-power
(HP)
1250 mA 150 RPM 25 oz-in 120:1 mini HP 120:1 mini HP 120:1 mini HP 120:1 mini HP
low-power 800 mA 120 RPM 20 oz-in 120:1 mini 120:1 mini 120:1 mini 120:1 mini
80 RPM 30 oz-in 180:1 mini 180:1 mini


We are particularly excited about these gearmotors because they offer a great combination of performance and affordability; don’t be surprised if you find these motors in some of our future robots and robot kits! For more information about all of these gearmotors, see our Mini Plastic Gearmotors category.

Motion tracking skull Halloween prop

Posted by Brandon on 7 October 2014
Motion tracking skull Halloween prop

If you read Grant’s Creepy eyes Halloween prop post, then you already know that several of us here at Pololu are working on Halloween projects. I based my project on a motion tracking Halloween prop tutorial by Jason Poel Smith that I saw last year on the Make magazine website. The concept is simple: make a Halloween prop mysteriously follow an unsuspecting person as they walk by. The tutorial by Jason Smith uses photoresistors to track a person by detecting their shadow and moving a servo with a Halloween prop attached to it. This works well, but there are a few things that I thought could be improved. Continued…

RoboNUC: Netduino and LIDAR robot

Posted by Brandon on 16 September 2014
RoboNUC: Netduino and LIDAR robot

Pololu forum member spiked3 recently shared a sophisticated robot he made called RoboNUC. It uses a Netduino and a LIDAR module and was intended to help him learn simultaneous localization and mapping (SLAM). SLAM is a technique used to map an unknown environment and keep track of the device’s location within the environment. Using SLAM, the robot is able to characterize the surrounding areas without needing to physically navigate them. RoboNUC uses our 1″ plastic ball caster, and the acrylic chassis was laser cut using our custom laser cutting service.

For more information about this robot, including a parts list, please see the RoboNUC Recap blog post at Spiked3.com.

New product: Breakout Board for microSD Card

Posted by Brandon on 10 September 2014
Tags: new products
New product: Breakout Board for microSD Card

Last week, Jon mentioned how several of the mechanical engineers here at Pololu were assigned a simple board to develop. Well, our new Breakout Board for microSD Card is the first board that I designed!

Electrically, this board is pretty basic. It breaks out all of the connections available on a microSD card into two rows of 0.1″-spaced pins for easy prototyping use with standard perfboards, solderless breadboards, and 0.1″ connectors. We tried to arrange the pins in a convenient order by placing all of the pins needed for SPI mode on one side of the board (along with the card detect pin). What makes this board interesting mechanically is that it is the first of our products to use a connector for a microSD card. The push-push type connector is positioned so that when a microSD card is fully inserted, it protrudes slightly beyond the edge of the board to allow easy access to the card. The integration of our electrical and mechanical procedures allows us to make 3D models such as the one below to help support our products. We currently use models like this in the dimension diagrams we publish for our boards, but we hope to eventually make the models themselves available too.

Breakout Board for microSD Card rendered in Solidworks.

Integration with 5 V systems

There are no other components on the board aside from the microSD card connector. Since standard microSD cards use 3.3 V logic, no extra considerations need to be taken to use it with a 3.3 V microcontroller, but signal conditioning is required for use with 5 V microcontrollers. We did some tests using our 4-channel level shifter and an Arduino Uno to read and write from a microSD card using the Arduino SD library, and we had successful results; however upon closer inspection, we noticed the level shifter did not have time to shift the 3.3 V signals all the way up to 5 V, so this setup only worked because the Arduino Uno registered 3.3 V as a high signal. With a 5 V microcontroller that accepts a 3.3 V signal as high, the microSD card outputs can be connected directly to the microcontroller, and the microcontroller’s 5 V outputs can be shifted to 3.3 V using a simple voltage divider. We found the resistor values needed to be fairly low – we settled on 500 Ω and 1 kΩ resistors. Since we used the standard Arduino SD library, our tests were done at SPI speeds of 4 MHz. In systems operating at higher speeds or with more stringent logic voltage requirements, it might be necessary to use a buffer IC or other high-speed level-shifting solutions.

For more information about this breakout board, see its product page.

New products: CC3000 Wi-Fi breakout board and Arduino shield from Adafruit

Posted by Brandon on 22 July 2014
Tags: new products
New products: CC3000 Wi-Fi breakout board and Arduino shield from Adafruit

Adding wireless connectivity to an electronics project is a great way to enhance functionality and make it stand out. Our selection of wireless electronics includes radio frequency modules, such as the Wixel, and Bluetooth modules, like the BlueSMiRF Silver from SparkFun, but until recently, we did not carry a good solution to adding Wi-Fi to a project. That’s where the newest additions to our wireless selection come into play.

We are now carrying two CC3000 Wi-Fi module carrier boards from Adafruit: the CC3000 Wi-Fi Shield for Arduino and CC3000 Wi-Fi breakout board. The CC3000 is a self-contained wireless network processor with an SPI interface, so it is not limited to a fixed UART baud rate, and the Adafruit carrier boards include level shifters, so they should be simple to connect to almost any microcontroller. Adafruit’s CC3000 Arduino library and example sketches make them especially easy to use with an Arduino-compatible board.

Adafruit CC3000 Wi-Fi breakout board with onboard ceramic antenna.
Adafruit CC3000 Wi-Fi Shield, assembled and connected to an Arduino UNO R3.

The CC3000 Wi-Fi Shield for Arduino offers a MicroSD card socket, a prototyping area for soldering extra circuitry, and a button for resetting the Arduino. The CC3000 Wi-Fi breakout board (v1.1) is much more compact and is also breadboard-compatible. Both products include an onboard ceramic antenna.

Wi-Fi controlled Zumo Chassis with DRV8835 and GoPro

Posted by Brandon on 26 June 2014

Forum user Pablo shared his Wi-Fi controlled robot with pictures and videos from his Instagram. In Pablo’s forum post, he summarizes his project, which consists of a custom PCB that he designed himself to interface a PIC18F26K20 with a MRF24WB0MA Wi-Fi module. His custom board also carries a DRV8835 motor driver and is mounted on a Zumo Chassis. The robot is controlled through Wi-Fi using a custom Android app and has a GoPro camera mounted on the Zumo blade. Finally, to top it all off, he placed a 6" Domo plush doll on top.

The picture below shows his fully assembled PCB, and Pablo posted a sped up video of its assembly.

For more details, including links to more of Pablo’s Instagram videos of his project like this one, please see Pablo’s original post.