Autonomous Rover Navigates The House With LIDAR

September 22, 2020 by Zoe Skyforest 1 Comment

For those wishing to explore robot autonomy, there’s no better way then to learn by doing. [Greg] was in that camp, and decided to build an autonomous rover to roam his house, and learned plenty along the way.

[Greg]’s aims with the project were to build a robot that was capable of navigating his home without external assistance. To do the job, a Raspberry Pi 3 was put in charge, and kitted out with a LIDAR for mapping. Pololu Roboclaw motor controllers are then used to allow the Raspberry Pi to drive the robot’s individual wheel motors, giving the four-wheeled bot skid steering capability.

[Greg] goes into immense detail on the project’s writeup, exploring the code and concepts behind its autonomous abilities. Creating a robot that can navigate using LIDAR is no easy task, but [Greg] does a great job of explaining how it all works, and why.

It’s not the first autonomous rover we’ve seen here, and we’re sure it won’t be the last. If you’ve got your own build coming together in the lab, be sure to let us know. Video after the break.

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Building A Cell Testing Station For 18650s

September 21, 2020 by Zoe Skyforest 34 Comments

The 18650 is perhaps the world’s favorite lithium battery, even if electric car manufacturers are beginning to move towards larger cells such as the 21700. Used heavily in laptops and flashlights, it packs a useful amount of energy into a compact, easy to use package. There’s a small industry that has developed around harvesting these cells from old equipment and repurposing them, and [MakerMan] wanted to a piece of the action. Thus, he created a cell testing station to help in the effort.

Make no mistake, this is not a grandiose smart cell tester with 40 slots that logs every last iota of data into a cloud spreadsheet for further analysis. Nope, this is good old fashioned batch processing. [MakerMan] designed a single PCB that replicates the same cell testing circuit four times. Since PCB houses generally have a minimum order quantity of ten units, [MakerMan] ended up with forty individual cell testers on ten PCBs. Once populated, the boards were installed on a wooden frame with an ATX power supply which supplies the juice to run the system.

Overall, it’s a quick, cheap way for capacity testing cells en masse that should serve [MakerMan] well. We look forward to seeing where these cells end up. We’ve seen his work before, too – with a self-built laser engraver a particular highlight. Video after the break.

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A Budget Testing Rig For Low-Volume Production

September 20, 2020 by Zoe Skyforest 2 Comments

It’s not unheard of for those who tinker in the land of electronics to suddenly find themselves with a project on their hands and potential customers clamoring at the door. Of course, the road to shipping a product is a long one, and requires a unique set of skills quite distinct from those required to build the initial prototype. In developing a product for Airsoft use, [bald greg] realized that a testing rig would be key to ensuring their hundreds of units left the building in working condition.

When shipping units in the hundreds rather than thousands, keeping overheads low is key to maintain a sustainable profit margin on each unit sold. Thus, [bald greg] built a rig that would allow for effective testing of devices rather than breaking the bank. The rig also handles programming, saving the cost of purchasing pre-programmed microcontrollers from the manufacturer. A Raspberry Pi runs the show, using its GPIO pins to program boards and saving test results and serial numbers for later reference. A bed of nails fixture is used to connect to each individual board. Additionally, to test each board as realistically as possible, hardware mimicking a real Airsoft electric pistol is used to properly load the hardware.

[bald greg]’s work is a great example of approaching QC on a budget, and we suspect he’ll sleep soundly knowing the boards in the mail are going to work first time. We’ve seen others take similar approaches, too. If you’re working on your own production testing rig, be sure to let us know!

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Rolex Becomes World’s Most Expensive ESD Strap

September 19, 2020 by Zoe Skyforest 26 Comments

Anti-static ESD straps are de rigueur in lab settings for those working with sensitive electronics. They’re a simple protective device, and one that generally doesn’t warrant a second thought. However, [Daniel Bogdanoff] figured they could stand to be a little more fashionable, and set to work on a fancier design.

The first step was to take a look at a regular ESD strap. Typically, they consist of a band that fastens around the wearer’s wrist, with a metal stud for connecting to the earthing lead. The earthing lead contains a high resistance to limit the discharge current to avoid ugly high-energy shorts when wearing the strap.

The metal stud is attached to a replacement link on the ROLEX’s strap, making the modification neat, tidy, and reversible.

With a good understanding of the basics, [Daniel] set about modifying a CASIO calculator watch for practice. After soldering a metal stud to the watch case failed, a second attempt with conductive epoxy worked great. The watch could be connected to the earthing strap, and an ESD tester confirmed the device was doing its job.

But unfortunately, permanently modifying the borrowed ROLEX wasn’t an option. Instead, [Daniel] limited his work to a single replacement link which could be inserted into the watch band. Hooked up to an earthing strap, the luxury watch also passed a basic ESD test successfully.

[Daniel] notes that while this is a fun experiment, using properly rated safety equipment is best. Additionally, he points out that the ROLEX is likely to do worse than the CASIO for the simple fact that a metal-banded watch is more likely to cause shorts when working on electronics. Of course, if a watch isn’t your thing, consider a ring instead. Video after the break.

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Closely Examining How A PG&E Transmission Line Claimed 85 Lives In The 2018 Camp Fire

September 17, 2020 by Zoe Skyforest 100 Comments

In 2018, the Camp Fire devastated a huge swathe of California, claiming 85 lives and costing 16.65 billion dollars. Measured in terms of insured losses, it was the most expensive natural disaster of the year, and the 13th deadliest wildfire in recorded history.

The cause of the fire was determined to be a single failed component on an electrical transmission tower, causing a short circuit and throwing sparks into the dry brush below – with predictable results. The story behind the failure was the focus of a Twitter thread by [Tube Time] this week, who did an incredible job of illuminating the material evidence that shows how the disaster came to be, and how it could have been avoided.

Mismanagement and Money

The blame for the incident has been laid at the feet of Pacific Gas and Electric, or PG&E, who acquired the existing Caribou-Palermo transmission line when it purchased Great Western Power Company back in 1930. The line was originally built in 1921, making the transmission line 97 years old at the time of the disaster. Despite owning the line for almost a full century, much of the original hardware was not replaced in the entire period of PG&Es ownership. Virtually no records were created or kept, and hardware from the early 20th century was still in service on the line in 2018.

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Vacuum Dragster Uses Syringes For Propulsion

September 17, 2020 by Zoe Skyforest 16 Comments

Atmospheric pressure is all around us, and capable of providing a great deal of force when used properly. As Otto Von Guericke demonstrated with his Magdeburg hemispheres over 350 years ago, simply removing air from a chamber to create a vacuum can have astounding results. More recently, [Tom Stanton] has used vacuum to power a small 3D-printed dragster.

In the dragster build, a typical plunger syringe is plugged at the end, and the plunger pulled back. Atmospheric pressure acts against the vacuum, wanting to push the plunger back towards its original position. To make use of this, a string is attached to the plunger, causing it to turn a gear as it moves forward, driving the rear wheels through a belt drive. With the correct gear ratio on the belt drive, the dragster is capable of spinning its tires and shooting forwards at a quick pace.

The work is a great follow on from [Tom]’s earlier vacuum experiments, using syringes as small rockets. It reminds us of the classic CO2 dragsters from high school competitions, and would be a great project for any science class. Video after the break.

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Underwater Datacenter Proves To Be A Success

September 17, 2020 by Zoe Skyforest 65 Comments

Back in 2018, Microsoft began Project Natick, deploying a custom-designed data center to the sea floor off the coast of Scotland. Aiming to determine whether the underwater environment would bring benefits to energy efficiency, reliability, and performance, the project was spawned during ThinkWeek in 2014, an event designed to share and explore unconventional ideas.

This week, Microsoft reported that the project had been a success. The Northern Isles data center was recently lifted from the ocean floor in a day-long operation, and teams swooped in to analyse the hardware, and the results coming out of the project are surprisingly impressive.

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