A white male in a green shirt sitting next to a tall rectangular robot made of green and black components with an aluminum frame. In front of him are a variety of components from several windshield wiper motor assemblies. Casings, gearboxes, and the like are strewn across the wooden table.

A Wiper Motor 101

February 2, 2024 by Navarre Bartz 22 Comments

Need a powerful electric motor on the cheap? [Daniel Simu] and his friend [Werner] show us the ins and outs of using windshield wiper motors.

Through many examples and disassembled components, the duo walk us through some of the potential uses of wiper motors to power a project. Some of the nuggets we get are the linear relationship of torque to current (10-15A max) and speed to voltage (12-15V DC) on these units, and some of the ways the wiring in these motors is a little different than a simple two wire DC motor.

They also discuss some of their favorite ways to control the motors ranging from a light switch to an Arduino. They even mention how to turn one into a big servo thanks to a project on Hackaday.io and a few modifications of their own. [Simu] also discusses some of the drawbacks of wiper motors, the most evident being that these motors use nylon gears which are prone to stripping or failing in other ways when subjected to high torque conditions for too long.

If you recognize [Simu], it may be from his robotic acrobat built with wiper motors. Want to see some more wiper motor hacks? How about a 3D scanner or making sure your wipers always keep the beat?

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Motorized Camera Slider Rides On Carbon

September 1, 2023 by Bryan Cockfield 1 Comment

While not every camera mount needs to have six degrees of freedom, one or two can be extremely helpful in the photographic world. In order to make time-lapse shots with some motion or shots that incorporate some parallax, a moving camera mount or dolly is needed, and this small one builds upon a pre-existing, although non-motorized, camera slider.

The slider is an inexpensive model from everyone’s favorite online warehouse, with rails that are at least coated in carbon, if not made out of it entirely, to ensure smooth camera motion. To add the motorization to automatically move the camera, a stepper motor with a belt drive is used which is controlled by an Arduino. A few limit switches are added, letting the dolly perform different movement patterns automatically, and a pair of potentiometers for fine and coarse speed control are included as well, letting the camera take both time-lapse and video while using this mount at various controllable speeds.

With everything tucked into a relatively small box at one end of the dolly, the build is both accessible and functional. The code for the microcontroller is also available on the project’s GitHub page for anyone looking to replicate or build upon the project. And, for those looking to add more degrees of freedom to their camera setups, take a look at this DIY pan and tilt mount.

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Presence Sensor Locks Computer When You Step Away

July 2, 2023 by Bryan Cockfield 14 Comments

Having a computer that locks its screen after a few minutes of inactivity is always a good idea from a security standpoint, especially in offices where there is a lot of foot traffic. Even the five- or ten-minute activity timers that are set on most workstations aren’t really perfect solutions. While ideally in these situations we’d all be locking our screens manually when we get up, that doesn’t always happen. The only way to guarantee that this problem is solved is to use something like this automatic workstation locker.

The project is based around the LD2410 presence sensor — a small 24 GHz radar module featuring onboard signal processing which simplifies the detection of objects and motion. [Enzo] paired one of these modules with a Seeed Studio XIAO nRF52840 development board to listen to the radar module and send the screen lock keyboard shortcut to the computer when it detects that the user has walked away from the machine. The only thing that [Enzo] wants to add is a blinking LED to let the user know when the device is about to timeout so that it doesn’t accidentally lock the machine when not needed.

One of the parts of this build that is a little bit glossed over is the fact that plenty of microcontroller platforms can send keystrokes to a computer even if they’re not themselves a USB keyboard. Even the Arduino Uno can do this, so by now this feature is fairly platform-agnostic. Still, you can use this to your advantage if you have the opposite problem from [Enzo] and need your computer to stay logged in no matter what.

Robot’s Actions And Our Reactions

January 12, 2019 by Brian McEvoy 9 Comments

If you walk into a dog owner’s home that dog is probably going to make a beeline to see if you are a threat. If you walk into a cat owner’s home, you may see the cat wandering around, if it even chooses to grace you with its presence. For some people, a dog’s direct approach can be nerve-wracking, or even scary depending on their history and relative size of the dog. Still, these domestic animals are easy to empathize with especially if you or your family have a pet. They have faces which can convey curiosity or smug indifference but what if you were asked to judge the intent of something with no analogs to our own physical features like a face or limbs? That is what researchers at the IDC Herzliya in Israel and Cornell University in the US asked when they made the Greeting Machine to move a moon-like sphere around a planet-like sphere.

Participants were asked to gauge their feelings about the robot after watching the robot move in different patterns. It turns out that something as simple as a sphere tracing across the surface of another sphere can stir consistent and predictable emotions in people even though the shapes do not resemble a human, domestic pet, or anything but a snowman’s abdomen. This makes us think about how our own robots must be perceived by people who are not mired in circuits all day. Certainly, a robot jellyfish lazing about in the Atlantic must feel less threatening than a laser pointer with a taste for human eyeballs.

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Super Simple Sensor Makes DSLR Camera Motion Sensitive

January 5, 2019 by Dan Maloney 11 Comments

Do you have a need to photographically document the doings of warm-blooded animals? If so, a game camera from the nearest hunting supplier is probably your best bet. But if you don’t need the value-added features such as a weather-resistant housing that can be chained to a tree, this DIY motion trigger for a DSLR is a quick and easy build, and probably loads more fun.

The BOM on [Jeremy S Cook]’s build is extremely short – just a PIR sensor and an optoisolator, with a battery, a plug for the camera’s remote jack, and a 3D-printed bracket. The PIR sensor is housed in a shroud to limit its wide field of view; [Jeremy] added a second shroud when an even narrower field is needed. No microcontroller is needed because all it does is trigger the camera when motion is sensed, but one could be added to support more complicated use cases, like an intervalometer or constraining the motion sensing to certain times of the day. The video below shows the build and some quick tests.

Speaking of intervalometers, we’ve seen quite a few of those over the years. From the tiny to the tinier to the electromechanical, people seem to have a thing for taking snapshots at regular intervals.

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A Super Simple ESP8266 IOT Motion Sensor

July 19, 2018 by Tom Nardi 31 Comments

It’s really hard to overstate how awesome ESP8266 development boards like the Wemos D1 Mini really are. For literally a couple of dollars you can get a decently powerful Wi-Fi enabled microcontroller that has enough free digital pins to do some useful work. Like the Arduino and Raspberry Pi before it, the ESP8266 is a device that’s opening up whole new areas of hacking and development that simply weren’t as practical or cost-effective as previously.

As a perfect example, take a look at this stupendously simple Internet-connected motion detector that [Eric William] has come up with. With just a Wemos D1 Mini, a standard PIR sensor, and some open source code, you can create a practical self-contained motion sensor module that can be placed anywhere you want to keep an eye on. When the sensor picks up something moving, it will trigger an IFTTT event.

It only takes three wires to get the electronics connected, but [Eric] has still gone ahead and provided a wiring diagram so there’s no confusion for young players. Add a 3D printed enclosure from Thingiverse and the hardware component of this project is done.

Using the Arduino Sketch [Eric] has written, you can easily plug in your Wi-Fi information and IFTTT key and trigger. All that’s left to do is put this IoT motion sensor to work by mounting it in the area to be monitored. Once the PIR sensor sees something moving, the ESP8266 will trigger IFTTT; what happens after that is up to you and your imagination. In the video after the break, you can see an example usage that pops up a notification on your mobile device to let you know something is afoot.

With its low cost and connectivity options, the ESP8266 is really the perfect platform for remote sensing applications. Though to give credit where credit’s due, this still isn’t the simplest motion sensor build we’ve seen.

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A Wireless Webcam Without A Cumbersome Cloud Service

December 8, 2017 by James Hobson 42 Comments

After a friend bought a nannycam that required the use of a cloud service to make the device useful, [Martin Caarels] thought to himself — as he puts it — ”I can probably do this with a Raspberry Pi!”

Altogether, [Caarels] gathered together a 4000mAh battery, a Raspberry Pi 3 with a micro SD card for storage, a Logitech c270 webcam, and the critical component to bind this project together: an elastic band. Once he had downloaded and set up Raspbian Stretch Lite on the SD card, he popped it into the Pi and connected it to the network via a cable. From there, he had to ssh into the Pi to get its IP so he could have it hop onto the WiFi.

Now that he effectively had a wireless webcam, it was time to turn it into a proper security camera.

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