A graphing calculator with a 3D-printed enclosure, with a circuit board next to it

2022 Cyberdeck Contest: The Galdeano Is More Than A Graphing Calculator

September 15, 2022 by Robin Kearey 14 Comments

Graphing calculators have evolved from expensive playthings for rich nerds to everyday tools for high schoolers worldwide. Even though teenagers nowadays carry powerful internet-connected computers in their pockets, math teachers often prefer them to use a clunky Z80-powered calculator in class, if only because their limited performance reduces the potential for distraction. The worst thing a lazy student can do is play a simple game like Snake or Tetris.

But what if you’re not a student anymore and you want a graphing calculator that has up-to-date hardware and infinite customizability in software? Look no further than [Angel Cabello]’s Galdeano, a handheld that has all the features of a modern graphing calculator plus a lot more. The heart of the device is an ESP32, which sits on a custom PCB that also holds a 6×7 array of push-buttons and a 320×240 touch-sensitive color display. It can be powered through a lithium-polymer battery or, like a classic calculator, through four AAA cells. The entire thing is housed in a 3D printed enclosure with color-coded buttons indicating various built-in functions.

The ESP32 runs MicroPython along with a symbolic math engine called Eigenmath. This enables the Galdeano to manipulate expressions, perform integration and differentiation, and plot functions. Porting Eigenmath to a memory-constrained platform like the ESP32 was quite a challenge and required a few workarounds, including a memory partition scheme and even a custom compact font with mathematical symbols.

Thanks to the flexibility of MicroPython and the ESP’s WiFi system, the Galdeano is not limited to implementing a calculator: it can also perform various general-purpose tasks ranging from file editing to controlling a set of smart light bulbs. The project page doesn’t mention any games yet, but we’re sure it won’t take long before someone ports Tetris to this system as well.

Of course, even classroom-grade calculators can be pushed to do much more than their designers intended: they can receive GPS signals, run Debian or even perform ray tracing. If you’re looking for a powerful open-source calculator, this BeagleBoard-based machine runs the R statistical computing environment.

Continue reading “2022 Cyberdeck Contest: The Galdeano Is More Than A Graphing Calculator” →

A display in a field showing the water stress index over time

Hackaday Prize 2022: Using Infrared Thermometers To Measure Crops’ Water Stress

September 11, 2022 by Robin Kearey 6 Comments

If you live anywhere on the Northern Hemisphere, you’re likely to have experienced one of the many heatwaves that occurred this summer. Extreme heat is dangerous for humans and animals, but plants, including important crops, also suffer. High temperatures lead to increased transpiration and evaporation, and if the water lost in this way is not replenished quickly enough, plants will stop growing and eventually wither and die.

In order to keep track of the amount of water available to crops, [Florian Ellsäßer] built the Crop Water Stress Sensor: a device that checks whether plants have enough moisture available to stay healthy. It does this by measuring the temperature of the leaves to calculate evaporation levels. If the leaves are cooler than their surroundings, this means that water is evaporating from them and the plant apparently has enough water available. If the leaves’ temperature is closer to the ambient temperature, then the plant may be running low on water.

[Florian]’s system performs this measurement using an infrared array, which is basically a low-resolution thermal camera that remotely measures the temperature of everything in its field of view. This IR array is pointed at a field, where it will see both leaves and the ground between them. The difference in temperature between these two can then be used to calculate the Crop Water Stress Index (CWSI), a standardized measure of how well-hydrated plants are. The result is shown on a display and also indicated using a convenient red-yellow-green status LED that shows if the crops in question need watering.

The system can be solar powered for completely remote operation, while its data can be read out through a WiFi interface. [Florian] is planning to update the design with a LoRa interface for greater range: the eventual goal is to build a large network of these sensors throughout agricultural areas and use the combined data to raise awareness of water shortages in certain areas. In order to make the sensors easy to build by anyone interested, all design files are available on the project page.

Keeping crops moisturized is one of the key tasks of agriculture, and we’ve seen several projects that aim to optimize and automate it, from a simple-but-effective ESP8266-based moisture sensor to complete hydroponics systems.

A black PCB with an ESP32 and an SBM-20 geiger counter

Flexible Radiation Monitoring System Speaks LoRa And WiFi

September 10, 2022 by Robin Kearey 12 Comments

Radioactivity has always been a fascinating phenomenon for anyone interested in physics, and as a result we’ve featured many radioactivity-related projects on these pages over the years. More recently however, fears of nuclear disaster have prompted many hackers to look into environmental radiation monitoring. [Malte] was one of those looking to upgrade the radiation monitor on his weather station, but found the options for wireless geiger counters a bit limited.

So he decided to build himself his own Wifi and LoRa compatible environmental radiation monitor. Like most such projects it’s based on the ubiquitous Soviet-made SBM-20 GM tube, although the design also supports the Chinese J305βγ model. In either case, the tube’s operating voltage is generated by a discrete-transistor based oscillator which boosts the board’s 5 V supply to around 400 V with the help of an inductor and a voltage multiplier.

Graphs showing temperature, humidity and radiation levels — Data can be visualized in graphs, together with other data from the weather station like temperature and humidity

The tube’s output signal is converted into clean digital pulses to be counted by either an ESP32 or a Moteino R6, depending on the choice of wireless protocol. The ESP can make its data available through a web interface using its WiFi interface, while the Moteino can communicate through LoRa and sends out its data using MQTT. The resulting data is a counts-per-minute value which can be converted into an equivalent dose in Sievert using a simple conversion formula.

All design files are available on [Malte]’s website, including a PCB layout that neatly fits inside standard waterproof enclosures. Getting more radiation monitors out in the field can only be a good thing, as we found out when we tried to detect a radiation accident using community-sourced data back in 2019. Don’t like WiFi or LoRa? There’s plenty of other ways to connect your GM tubes to the internet.

A device with pipes and pumps sitting next to a body of water

Hackaday Prize 2022: Otter Force One Protects Kelp Forests By Sucking Up Sea Urchins

September 8, 2022 by Robin Kearey 10 Comments

When thinking about forests being endangered by human activity, most people would immediately think of the rainforest. Below the ocean surface, there’s another type of forest is in danger: the kelp forests off the coast of northern California. Warming sea water has triggered an explosion in the population of purple sea urchins (Strongylocentrotus purpuratus) which devour kelp at an alarming rate. It’s estimated that 90% of kelp forests have been lost to the urchins along a 350 km stretch of coastline.

The fix is as simple as getting rid of the urchins, but collecting the millions of spiny creatures manually isn’t realistic. Luckily, [RobotGrrl] designed just the tool for this task: Otter Force One, an autonomous underwater robot that can gather the aquatic interlopers and put them in a bag for removal. The device is still under development, but progress so far has been promising. The basic idea is to identify an urchin using machine vision, then dislodge it with a water jet, and finally to use a suction pump to pull it inside the machine and store it in a bag.

A prototype made from 3D printed components is currently being used to test the idea. Its motors are driven by an ESP32 with a motor controller, with the system powered by a set of beefy lithium batteries. Tests with plastic urchin models confirm that the suction mechanism works, though the water jet and machine vision systems still need to be tested. But even without these in place the Otter Force One can still be used by human divers to improve their urchin-gathering efficiency.

We’ll definitely keep an eye on this project, and hopefully see it evolve into a fully-automated urchin hunter. Underwater pest-control robots are not completely new: we already saw a laser-powered delouser for use on salmon farms. There are also robotic starfish and octopuses.

Front and back of a handheld 6502 computer with bubble LED displays

The Pocket265 Is A Pocket-Sized 6502 Single-Board Computer

September 7, 2022 by Robin Kearey 13 Comments

Single-board computers have been around ever since microprocessors became affordable in the 1970s and never went away. Today we have Raspberry Pis and LattePandas, while back in the ’70s and ’80s there were the Ferguson Big Board, the KIM-1 and a whole array of Intel SDK boards. Although functionally similar to their modern counterparts with a CPU, RAM, ROM and some basic peripherals, the old boards were huge compared to today’s tiny platforms and typically required a rather beefy power supply to operate.

It doesn’t have to be that way though, as [Aleksander] shows with the Pocket265: a handheld 6502 single-board computer somewhat reminiscent of the famous KIM-1. Like that classic machine, it’s got a hexadecimal keypad to enter programs using machine code and a row of LED displays to show the programs’ output. Unlike the KIM, the Pocket265 is small enough to hold in one hand and uses bubble LED displays, which make it look more like a programmable calculator from the 1970s. It comes with a lithium battery that makes it truly portable, as well as a sleek 3D printed case to make it more comfortable to hold than a bare circuit board.

The single ROM chip contains a monitor program that runs the basic user interface. It also makes programming a bit less tedious by implementing a number of system calls to handle things like user input and display output. A serial EEPROM enables local data storage, while a UART with a USB interface enables data transfer to other computers. If you’re interested in building and programming such a machine yourself, [Aleksander] helpfully provides code examples as well as full hardware documentation on his GitHub page.

The 6502 remains a firm favorite among hardware hackers: some projects we recently featured with this CPU include one beautifully made machine, this easy-to-build single-board computer and this huge breadboard-based contraption. Looking for something smaller? Try this tidy little board or this 6502 coupled to an FPGA.

A portable computer built inside a rugged carrying case

2022 Cyberdeck Contest: The Black Beast Will Help You Survive A Robot Apocalypse

September 4, 2022 by Robin Kearey 19 Comments

With AI systems getting smarter every day, one might wonder if they might someday evolve into a sentient Skynet-like system and try to take over the world. We’re not sure how close we are to such a situation, but we do know that if the robot apocalypse were to happen, we would want to stay close to [LordOfAllThings], who would likely be carrying the Black Beast. This scary-sounding machine is in essence a Raspberry Pi-based portable computer built inside an outdoor carrying case, with a wide range of unusual peripherals that make it the digital equivalent of a Swiss army knife. In other words, it’s a cyberdeck built for end times — and whatever comes after.

For example, an array of ESP32-based modules plus an SDR module allow you to intercept and analyze hostile robots’ communications, whether they’re using Bluetooth, WiFi, LoRaWAN, or anything in the 433 or 868 MHz ranges. An FM transmitter comes in handy for reaching out to fellow citizens who are trapped with nothing more than an analog radio receiver, while a suite of environmental sensors (including a Geiger counter) should help determine if Skynet has released any harmful substances to flush out those last few pesky humans. (Ed. note: No marigolds in the promised land and all that.)

If you manage to find a wired Ethernet connection somewhere, a built-in five-port gigabit router lets you set up a local network, obviously with a custom network analyzer to detect any unwanted intrusions. A storage compartment contains every kind of cable you could need, as well as useful gadgets like flashlights and, indeed, an actual Swiss army knife.

Continue reading “2022 Cyberdeck Contest: The Black Beast Will Help You Survive A Robot Apocalypse” →

A complex piece of laboratory glassware with liquid metal inside

A Liquid Metal Fountain That Works At Room Temperature

September 1, 2022 by Robin Kearey 26 Comments

A fountain is a great way of adding a little flair to an otherwise boring pond. All you need is a pump, a filter and some pipes, along with a nozzle to scatter the pressurized water in some aesthetically pleasing way. Fountains are generally quite safe: if any of the parts malfunction, the worst thing that can happen is some minor flooding.

How different this is for [Advanced Tinkering]’s recent project, the NaK Fountain. If this one were to spring a leak, it’s quite likely to take out its surroundings in a huge fireball. That’s because the fluid inside is an alloy of sodium and potassium in about a 1:3 ratio, known as NaK (pronounced like “knack”), which is a liquid at room temperature. Unfortunately, it’s also highly reactive: NaK oxidizes quickly when exposed to air and can even catch fire spontaneously. Contact with water will result in a fiery explosion that scatters corrosive liquids everywhere. Continue reading “A Liquid Metal Fountain That Works At Room Temperature” →