Pi

72 Articles

Pi Zero Powers A Little Indoor Rover

November 2, 2025 by 3 Comments

Not every robot has to be big. Sometimes, you can build something fun that’s better sized for exploring your tabletop rather than the wastelands of Mars. To that end, [philosiraptor] built the diminutive PITANK rover.

As you might guess from the name, the rover is based on the Raspberry Pi Zero 2. It uses the GPIO pins to output PWM signals, commanding a pair of servos that drive the tracks on either side of the ‘bot. The drivetrain and chassis are made from 3D-printed components. Controlling the robot is handled via a web interface, which [philosiraptor] coded in C# to be as responsive as possible. So you can see where you’re driving, the ‘bot is also kitted out with a camera to provide a live video feed.

Given its low ground clearance and diminutive size, you’re not going to go on big outdoor adventures with PITANK. However, if you wish to explore a nice flat indoor environment, its simple tracked drivetrain should do nicely. We’ve featured a great many rovers over the years; if you’ve got a particularly special one, don’t hesitate to notify the tipsline!

Regretfully: $3,000 Worth Of Raspberry Pi Boards

September 20, 2025 by 53 Comments

We feel for [Jeff Geerling]. He spent a lot of effort building an AI cluster out of Raspberry PI boards and $3,000 later, he’s a bit regretful. As you can see in the video below, it is a neat build. As Jeff points out, it is relatively low power and dense. But dollar for dollar, it isn’t much of a supercomputer.

Of course, the most obvious thing is that there’s plenty of CPU, but no GPU. We can sympathize, too, with the fact that he had to strip it down twice and rebuild it for a total of three rebuilds. One time, he decided to homogenize the SSDs for each board. The second time was to affix the heatsinks. It is always something.

With ten “blades” — otherwise known as compute modules — the plucky little computer turned in about 325 gigaflops on tests. That sounds pretty good, but a Framework Desktop x4 manages 1,180 gigaflops. What’s more is that the Framework turned out cheaper per gigaflop, too. Each dollar bought about 110 megaflops for the Pis, but about 140 for the Framework.

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2025 One Hertz Challenge: Estimating Pi With An Arduino Nano R4

August 9, 2025 by 10 Comments

Humanity pretty much has Pi figured out at this point. We’ve calculated it many times over and are confident about what it is down to many, many decimal places. However, if you fancy estimating it with some electronic assistance, you might find this project from [Roni Bandini] interesting.

[Roni] programmed an Arduino Nano R4 to estimate Pi using the Monte Carlo method. For this specific case, it involves drawing a circle inscribed inside a square. Points are then randomly scattered inside the square, and checked to see if they lie inside or outside the circle based on their position and distance of the circle’s outline from the center point of the square. By taking the ratio of the points inside the circle to the total number of points, you get an approximation of the ratio of the square and circle’s areas, which is equal to Pi/4. Thus, multiply the ratio by 4, and you’ve got your approximation of Pi.

[Roni] coded a program to run the Monte Carlo simulation on the Arduino Nano R4, taking advantage of the mathematical benefits of its onboard Floating Point Unit. It generates 100 new samples for the Monte Carlo approximation every second, improving the estimation of pi as it goes. It then displays the result on a 7-segment display, and beeps as it goes. [Roni] readily admits the project is a little too close in appearance to a classic Hollywood bomb.

We’ve seen some other neat Pi-calculating projects before, too.

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Pi Hand Is A Digital Display Of A Different Sort

March 14, 2025 by 8 Comments

Hackers enjoy a good theme, and so it comes as no surprise that every time March 14th (Pi Day) rolls around, the tip line sees an uptick in mathematical activity. Whether it’s something they personally did or some other person’s project they want to bring to our attention, a lot of folks out there are very excited about numbers today.

One of our most prolific circumference aficionados is [Cristiano Monteiro], who, for the last several years, has put together a special project to commemorate the date. For 2025, he’s come up with a robotic hand that will use its fingers to show the digits of Pi one at a time. Since there’s only one hand, anything higher than five will be displayed as two gestures in quick succession, necessitating a bit of addition on the viewer’s part.