Welcome to the Pololu Blog, where we provide updates about what we and our customers are doing and thinking about. This blog used to be Pololu president Jan Malášek’s Engage Your Brain blog; you can view just those posts here.
We are now selling T1-3/4 (5mm) common anode RGB LEDs! These multi-color LEDs contain red, green, and blue (RGB) elements that can be mixed to produce different colors. The three color elements share a common anode and are encased in a diffused white lens that blends the colors and widens the viewing angle. This product is a pack of five (5) RGB LEDs.
These LEDs replace the RGB LEDs with a common cathode that we used to sell. The common-anode setup of the new ones is nice because you can drive the LEDs with a low-voltage microcontroller I/O pin in an open-drain configuration (provided the pins can handle the current and are tolerant of the LED supply voltage). If you need to build your own drive circuit, you just need one low-side transistor per LED.
Here are some other posts on our blog about LEDs:
We now have a magnetic encoder pair kit available for our mini plastic gearmotors with extended back shafts. Like our encoder kit for micro metal gearmotors, these kits consist of Hall effect sensor boards that mount to the back of the motors and magnetic discs that fit on the motors’ back shafts. The encoders provide a resolution of 12 counts per revolution of the motor shaft (when counting both edges of both channels); in terms of counts per gearbox output shaft revolution, the resolution is multiplied by the corresponding gear ratio.
For more details about the encoder kit, see the product page.
Using an Arduino shield or Raspberry Pi add-on board is often a quick and convenient way to get started on a robotics project, but for maximum flexibility, nothing beats building your own system from standalone boards. Rud Merriam’s Hackaday article describes the design of his Raspberry Pi-controlled robot, for which he opted to use separate modules instead of daughterboards on the Pi, and mentions some of the trade-offs involved in making that decision.
The robot is built on a Wild Thumper chassis and uses a Maestro USB servo controller and two Simple Motor Controllers to interface the Raspberry Pi with the robot’s motors and actuators. In Rud’s writeup, he explains how he made use of some of the more advanced features of the Maestro and SMCs, like using servo channels for general-purpose I/O and setting up daisy-chained serial communications. Check out the full article for all of the details.
We’ve just released our VL53L0X Time-of-Flight Distance Sensor Carrier. With its ability to measure distances up to 2 m depending on configuration, target, and environment, the VL53L0X is a longer-range version of the VL6180X (but without ambient light sensing functionality) that operates using the same principles. This integrated lidar module times how long it takes for pulses of infrared light to reach a target, reflect off it, and arrive back at the sensor. It uses this information to report the range to the target with a resolution of 1 mm and accuracy as good as ±3%, minimizing the effect of the target’s reflectance on the measured distance.
VL53L0X datasheet graph of typical ranging performance (in default mode).
As usual, our breakout board adds a 2.8 V regulator and level shifters to help interface with 3.3 V and 5 V systems, as well as a breadboard-compatible pinout and mounting holes. We are also working on an Arduino library for the VL53L0X that we expect to release in the next few days.
For more information about the VL53L0X carrier, see its product page.
We are now offering the Hakko FA-400 Smoke Absorber. The Hakko FA-400 is a benchtop smoke absorber for removing smoke generated by soldering. It has an easily-replaceable activated-carbon filter and a sturdy ESD-safe housing that can be oriented horizontally or vertically.
Forum user LuisLabMO posted about his WiFi-controlled plant watering and monitoring system. The system uses SparkFun’s Blynk ESP8266 board to read various sensors that monitor sunlight, moisture content of the soil, and detect the level of water remaining in the watering reservoir. The Blynk signals our 5V relay module to activate the system’s water pump, which irrigates the plants through a drip system. You can read more about LuisLabMO’s watering system in his post, which also has a link to his Hackster.io project page and GitHub repository.
We’ve updated our USB Micro-B Connector Breakout Board with some minor improvements that should make it a little nicer to work with.
On the original version, the mounting cutouts didn’t work as well as we wanted: they were shallow, and the board was often prone to slipping out of place between two screws. The new version is wider and its cutouts are deeper to allow for more secure mounting, and it is slightly shorter in the other direction (0.4″ × 0.6″ with the connector).
For more information, see the board’s product page.
Our micro metal gearmotors are now available in 12 V versions! These high-power motors have long-life carbon brushes (HPCB) and offer the same performance as the 6 V HPCB motors at their respective nominal voltages; the only difference is that the 12 V motor draws half the current at twice the voltage.
The new 12 V gearmotors are available across our usual range of 11 gear ratios and in single- and dual-shaft versions. Along with our existing selection of micro metal gearmotors, this brings the total number of unique options available to 107:
@ Rated Voltage
@ Rated Voltage
@ Rated Voltage
(Gearbox & Motor)
|800 mA||6000 RPM||2 oz-in||5:1 HPCB 12V||5:1 HPCB 12V dual-shaft|
|3000 RPM||4 oz-in||10:1 HPCB 12V||10:1 HPCB 12V dual-shaft|
|1000 RPM||9 oz-in||30:1 HPCB 12V||30:1 HPCB 12V dual-shaft|
|625 RPM||15 oz-in||50:1 HPCB 12V||50:1 HPCB 12V dual-shaft|
|400 RPM||22 oz-in||75:1 HPCB 12V||75:1 HPCB 12V dual-shaft|
|320 RPM||30 oz-in||100:1 HPCB 12V||100:1 HPCB 12V dual-shaft|
|200 RPM||40 oz-in||150:1 HPCB 12V||150:1 HPCB 12V dual-shaft|
|140 RPM||50 oz-in||210:1 HPCB 12V||210:1 HPCB 12V dual-shaft|
|120 RPM||60 oz-in||250:1 HPCB 12V||250:1 HPCB 12V dual-shaft|
|100 RPM||70 oz-in||298:1 HPCB 12V||298:1 HPCB 12V dual-shaft|
|32 RPM||125 oz-in||1000:1 HPCB 12V||1000:1 HPCB 12V dual-shaft|
In celebration of Independence Day (July 4th), we are discounting selected products by up to 25% and offering an upgrade to the next best price break for everything else in our store. Please note that we will be closed Monday, so orders will not ship until Tuesday, July 5.
For more information, including all the discount coupon codes, see the sale page.
Happy 4th of July!
One of our customers, Jeff, found a creative way to use some of our 1″ ball casters. He was having a problem with the legs of his quadcopter “grabbing” when he landed, so he attached a ball caster to the end of each leg. You could read more about his modification and find more pictures of his quadcopter in his post on the RCGroups.com forum.