Raspberry Pi 4B

4 Articles

A red 3D-printed Raspberry Pi-based document scanner

Raspberry Pi Scanner Digitizes On The Cheap

April 17, 2024 by 29 Comments

It’s pretty important in 2024 to be able digitize documents quickly and easily without necessarily having to stop by the local library or buy an all-in-one printer. While there are plenty of commercial solutions out there, [Caelestis Cosplay] has created a simple document scanner that takes documents, as [Caelestis Cosplay] puts it, from papers to pixels.

The build is probably what you’re expecting — it’s essentially a Raspberry Pi (in this case a 4B), a V2 Pi camera, and a handful of custom 3D-printed parts. [Caelestis Cosplay] says they had never designed anything for printing before, and we think it looks great. There’s also a buzzer to indicate that the scan is starting (one beep) or has completed (two beeps), a ‘ready’ indicator, and a ‘working’ indicator.

Everything you’d need to build your own is available over on Instructables, including document scanner and controller scripts. Be sure to check it out in action after the break, and see it quickly scan in a document and put it on a thumb drive.

Looking for a 3D scanner? Check out the OpenScan project.

Continue reading “Raspberry Pi Scanner Digitizes On The Cheap” →

Showing a RAM chip being removed from a Pi 4 board, hot air gun in the shot. Area around the chip is covered with kapton tape.

Upgrade RAM On Your Pi 4, The Fun Way

March 5, 2023 by 17 Comments

The Raspberry Pi shortage has been a meme in hacker circles for what feels like an eternity now, and the Pi 4 seems to be most affected – though, maybe it’s just its popularity. Nevertheless, if you’re looking for a Pi 4, you would need to look far and wide – and things are way worse if you need the 8 GB version specifically. Or so we thought – [MadEDoctor] shows us that refreshing online store pages isn’t the only way, having successfully upgraded the RAM chip on the Pi 4 from 1 GB to 8 GB with help of a hot air gun.

These chips are BGA, and those might feel intimidating if you’re just starting out with hot air – however, we recommend you watch this video, as [MadEDoctor]’s approach is of the kind that brings BGA replacement to hobbyist level. First off, you get a compatible RAM chip somewhere like Aliexpress – lucky for us, those come equipped with a set of balls from the factory. The default balls are made of lead-free solder, and [MadEDoctor] reballed the RAM chip with leaded solder balls to lower the melting point, but it’s by no means a requirement that you do the same.

In fact, you only need a hot air gun, flux, a soldering iron and some solder wick to perform the replacement – no reballing equipment. Put some kapton or metal tape on the board for heat shielding, get the old chip off with hot air, use an iron with wick to clean the pads, add some flux, align the chip, then use hot air to solder a new chip onto the board. Replacing this chip can get your Pi 4 to the highly-sought-after 8 GB target – as an aside, we’re surprised that there was no configuration needed, as the Pi 4 booted right up and successfully recognized the extra RAM added.

We’d personally recommend preheating for such an upgrade – that said, this sure went without a hitch, and such a RAM swap method doesn’t require any stencils, solder paste or solder ball applications. Drop by the video description for compatible RAM chip part numbers, make sure you have your tacky flux and solder wick in order, and let [MadEDoctor] walk you through upgrading your Pi 4 the hacker way. Is this hack to your liking? Take it up a notch with this laptop soldered-in RAM upgrade journey, or that one RAM upgrade for an old GPU to comply to Apple’s whims.

Surfsonar shows the depth of water while surfing

Surf Sensor Adds Depth To Finding The Ultimate Wave

October 25, 2021 by 9 Comments

To say that the ocean is a dynamic environment would be a gross understatement, especially when coastlines are involved. Waves crash, tides go in and out, and countless variables make even the usual conditions a guessing game. When [foobarbecue] goes surfing, he tries to take into account all of these things. The best waves at his local beach are directly over an ever-moving sand bar, and their dynamics are affected by depth, another constant variable. [foobarbecue]’s brilliant solution to understanding current conditions? Build a depth finder directly into his surf board!

At the heart of the “surfsonar” is the Ping Sonar Echosounder, a sonar transducer designed for AUV’s and ROV’s. [foobarbecue] embedded the transducer directly into the board. Data is fed to a Raspberry Pi 4b, which displays depth and confidence (a percentage of how sure it is of the measurement) on a 2.13 inch e-Paper Display Hat.

Power is provided by a PiSugar. Charging is done wirelessly, which we’d say is pretty important considering that the whole device is sealed inside a modified surfboard.

While it’s not a low budget build, and there’s yet room for improvement, early reports are positive. Once away from the breaking waves, the device confidently shows the depth. More testing will show if the surfsonar will help [foobarbecue] find that ever-moving sandbar!

Surf hacks are always welcome, we’ve featured the LED Strip Lit Surfboard as well as the Surf Window, which tells its owner if the surf is up. Be sure to let us know about any cool hacks you find when you’re out surfing the ‘net via our Tips Line!

The Last Component Storage System You’d Ever Need

January 5, 2021 by 38 Comments

Think you’ve seen the best component storage system? This system could only be better if you could walk up and talk to it. [APTechnologies] was tired of using a hodgepodge of drawers and boxen for storing their components. What they needed was an all-purpose solution for storing all kinds of small-to-medium-sized goodies, be they through hole or SMT.

This one happens to have a software interface as well that is searchable with short, crisp expressions that find parts by ID or with parameters. It’s a Python 3 script running on a Raspberry Pi 4B that’s hiding behind the HDMI display. [APTechnologies] printed a special arm for that, and you can find all the files on GitHub. Not only does the LED above the corresponding drawer light up, it lights up in a color that represents the inventory levels. We assume green/yellow/red, but [APTechnologies] doesn’t specify.

Don’t know what to do with some of your components? If they’re really old, they may be no good anymore. It just depends.