Monthly Archives: April 2021

Video from content creator Curio Res: How to control a DC motor with encoder

via Pololu Blog

Content creator Curio Res recently released a tutorial and accompanying video explaining how to control a DC motor with an encoder. The video and post cover how to set up a motor with encoder, a controller, and a motor driver and how to read encoder signals. They also address common questions we get from customers who want to add closed-loop feedback to their projects such as how to implement a PID algorithm to control the position of the motor shaft based on the encoder readings. The content is well explained, and the diagrams and motion graphics make everything easy to follow and understand.

The tutorial uses one of our 37D Metal Gearmotors and our TB67H420FTG Motor Driver Carrier. The tutorial also uses an Arduino Uno, but one of our A-Star 32U4 Primes could be used instead.

If you like Curio Res’s content, be sure to subscribe to their YouTube channel so you don’t miss their latest videos. We look forward to seeing more great tutorials from Curio Res!

DIY GPS tracker helps you locate your stolen bike

via Arduino Blog

Bicycle theft is, unfortunately, a very common problem. Most bicycle locks are easy to overcome, which makes bike theft a crime of opportunity. Recovering a stolen one is usually improbable, but this DIY GPS tracker could provide the help that you need.

The GPS tracker, designed by Johan, is like Lojack for your bicycle. If the device detects that the bike has moved, it will send a text message and start tracking the GPS location. It will periodically send an update with the current location, so you can track down your stolen bike (with the help of the police).

The key component in this device is a MKR GSM 1400, which is a microcontroller development board that is capable of sending SMS messages over GSM cellular networks. It uses an ADXL345 three-axis accelerometer to sense when the bike moves. A MKR GPS Shield monitors the unit’s real-time physical location. Power comes from a 4400mAh lipo battery through a SparkFun LiPo Charger Plus board.

Those components are housed within a plastic case that mounts to the bike frame. Johan placed that case underneath his bike lock holder, so it isn’t obvious to would-be thieves. That helps to avoid the possibility of the thief removing the tracker before Johan can recover the bike. If you want to build your own tracker, Johan provides all the schematics and code that you need to tackle the project.

The post DIY GPS tracker helps you locate your stolen bike appeared first on Arduino Blog.

Haptic! At the Disco

via SparkFun: Commerce Blog

Hello and welcome, we are back again with more new products on this fine Friday! We are happy to announce two brand new Qwiic Haptic Drivers that both use the DA7280 motor from Dialog Semiconductor. One version of this new board comes in a typical breakout package, while the other breaks the Haptic motor off of the board and delivers you an option to build a kit! We close out the day with a new 1250 mAh lipo battery with certification! Now, let's jump in and see what we have!

I write code not tragedies

SparkFun Qwiic Haptic Driver - DA7280

SparkFun Qwiic Haptic Driver - DA7280


The SparkFun Qwiic Haptic Driver includes an itty-bitty, Linear Resonant Actuator (LRA) vibration motor and Dialog Semiconductor's DA7280 motor driver IC for applications that require haptic feedback.

Control the vibration motor with the DA7280 via I2C, PWM, or a combination of three general purpose input pins. Utilizing our handy Qwiic system, no soldering is required to connect it to the rest of your system. However, we still include 0.1"-spaced PTH pads in case you prefer to use a breadboard to access the driver's I2C, power, interrupt and general purpose input pins on the edge of the board.

SparkFun Qwiic Haptic Driver Kit - DA7280

SparkFun Qwiic Haptic Driver Kit - DA7280


The SparkFun Qwiic Haptic Motor Driver Kit includes the same itty-bitty, Linear Resonant Actuator (LRA) vibration motor, as well as wires and the breakout board for Dialog Semiconductor's DA7280 motor driver IC for applications that require haptic feedback. This kit is intended for applications where the vibration motor needs to be mounted separately from the board. Please be aware that you will need to manually solder the wires and motor to the board.

 Lithium Ion Battery - 1250mAh (IEC62133 Certified)

Lithium Ion Battery - 1250mAh (IEC62133 Certified)


These are very slim, extremely light weight batteries based on lithium ion chemistry. Each cell outputs a nominal 3.7 V at 1300 mAh and comes terminated with a standard 2-pin JST-PH connector with two-millimeter spacing between pins. Thanks to its IEC62133 certification, this battery is safe to use on professional IT, GNSS, Bluetooth® and other devices without any concern!

That's it for this week! As always, we can't wait to see what you make! Shoot us a tweet @sparkfun, or let us know on Instagram or Facebook. We’d love to see what projects you’ve made! Please be safe out there, be kind to one another, and we'll see you next week with even more new products!

Never miss a new product!

comments | comment feed

Building a low-cost flow meter for river studies

via Arduino Blog

Scientific equipment is notoriously expensive, and for schools, there are often monopolies on which suppliers can provide it. Eben Farnworth wanted to do something about this problem. His design for an open flow meter only costs around $60 USD, which pales in comparison to the typical price tag of $1,000.  

Flow meters are great tools to measure how quickly a liquid (typically water or air) passes through a certain area. By using a propeller inside of an enclosure with a known diameter, the amount of liquid per unit of time can be calculated, along with how fast it is going. Farnworth’s design employs a DN80 water sensor, an Arduino Uno, and a 2.4″ TFT touchscreen.

The case houses all the electronics plus a battery for power. Then at the bottom of the device is a port for plugging in the flow sensor itself. After a bit of calibration, Farnworth was able to get the display to show the flow of a river with impressive accuracy.

To read more about how this flow meter was engineered, check out Farnworth’s project write-up.

The post Building a low-cost flow meter for river studies appeared first on Arduino Blog.

How to Upgrade Firmware of a u-blox GNSS Receiver

via SparkFun: Commerce Blog

For GNSS positioning, u-blox has some of the most incredible receivers available. Over time they will release new versions of the firmware running on those receivers. The tutorial shown below will demonstrate how to upgrade the firmware on the ZED-F9P, but it can be used for nearly all u-blox receivers.

How to Upgrade Firmware of a u-blox GNSS Receiver

March 26, 2021

A few steps and you'll upgrade to the latest features on a u-blox GNSS receiver.

In just a few steps you'll have your favorite ZED-F9P, NEO-M8U, ZOE-M8Q, etc. board up to the latest code!

comments | comment feed

Arduino-controlled gas mixing device fills DIY laser tubes

via Arduino Blog

Lasers come in two varieties: solid-state and gas tube. As the name suggests, the latter types contain gas. That is a mixture of gas in precise proportions. To fill his DIY laser tube, Cranktown City built an Arduino-controlled gas mixer.

This device has an Arduino Uno board that drives three relay modules. The first relay switches power to a gas pump, the second relay controls an output valve, and the third relay controls an input valve. A push button starts the pumping process. The pump turns on and the input valve opens. Gas from a storage tank is pumped into an inflatable bag. Once the bag is full, as detected by a limit switch, the two valves flip and the gas pumps into the laser tube.

Cranktown City knows the exact volume of the inflatable bag, so he knows how much gas has been pumped into the laser tube each time the device runs. Like mixing a cocktail, this lets him “pour” each part of the gas mixture into the laser tube until he ends up with the correct proportions.

The gas pump, Arduino, relays, and inflatable bag are all enclosed within a heavy duty case made from steel sheet cut on a plasma table. The resulting mixer is portable and robust enough to stand up to abuse of a shop environment. With this device, Cranktown City can continue with developing his DIY laser tube — a project we can’t wait to see completed.

The post Arduino-controlled gas mixing device fills DIY laser tubes appeared first on Arduino Blog.