StarLink Terminal Unit Firmware Dumped

July 7, 2021 by Al Williams 17 Comments

There’s a lot of expense in what telephone companies call “the last mile” — delivering service from the main trunks to your home or business. StarLink wants to avoid that cost by connecting you via an array of low-orbit satellites and some users are already using the service. In Belgium, [Lennert Wouters] managed to dump the terminal’s firmware and has some interesting observations.

The teardown is actually more than just a firmware dump. His “level 1” teardown involves exposing the board. This can be tricky because there are apparently different versions of the terminal out already, so advice from one source might not match your hardware, and that was the case here.

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SimpleFOC Demystifies Precision BLDC Motor Control

July 7, 2021 by Sonya Vasquez 13 Comments

Brushless DC (BLDC) motors are standard fare in low-precision, speedy RC applications. The control schemes needed to run them slowly or precisely go deep into motor theory and might put these motors out of reach for your next homebrew robot project. [Antun Skuric] and crew aim to change just that. They’ve taken the field-oriented control algorithm and encapsulated it into a compact Arduino library, added a host of examples, and minted a stackable BLDC motor control shield to boot. The sum of their efforts is captured into the SimpleFOC Project in the aim of bringing precision BLDC control to a wide community of new hackers.

Field-Oriented Control is a BLDC motor control scheme that involves using a microprocessor to control the stator winding current in such a way that it always applies torque to the rotor. Doing so requires that your processor measure both motor current (think: shunt resistor) and rotor position (think: encoder). Implementing the algorithm, though, can get a bit tricky since it touches bits of linear algebra, motor physics, and control theory. But that’s the magic behind SimpleFOC. With the library at your fingertips, you don’t have to! And with that, the hardest part of brushless motor control has been made simpler with a solution that’s almost plug-in-and-play.

SimpleFOC has been implemented to extend to a variety of possible implementations. While you can certainly design your own control board, you can also start with the SimpleFOC motor shield for a single motor pulling up to 5 A of current. From there, you’ve got a pretty wide range of micros to choose from as the library has been extended to work on the Arduino, Teensy, STM32, and a few other microcontroller families. For implementation details, theory, and setup, there’s a healthy set of documentation to reference. And if you’re looking to share your project or ask questions, you can pop into the community forum for some high-fives and tips. Best of all, the source code has been offered for your enjoyment under a generous MIT License.

While the project kicked off last year, it’s undergoing continuous improvements including added support for current sensing and torque control in addition to position control. With a healthy community emerging around the project, we’ll keep our eyes peeled for more projects that build off of this fantastic reference design.

If BLDC motor control has your interest piqued, have a look through our archive for other BLDC motor control projects, including motor/controller hybrids, anti-cogging control schemes, and other low-speed position controllers. And if you’re up for a real challenge, why not 3D print the motor too?

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Recognising Bird Sounds With A Microcontroller

July 6, 2021 by Danie Conradie 4 Comments

Machine learning is an incredible tool for conservation research, especially for scenarios like long term observation, and sifting through massive amounts of data. While the average Hackaday reader might not be able to take part in data gathering in an isolated wilderness somewhere, we are all surrounded by bird life. Using an Arduino Nano 33 BLE Sense and an online machine learning tool, a team made up of [Errol Joshua], [Ajith KJ], [Mahesh Nayak], and [Supriya Nickam] demonstrate how to set up an automated bird call classifier.

The Arduino Nano 33 BLE Sense is a fully featured little dev board that features the very capable NRF52840 microcontroller with Bluetooth Low Energy, and a variety of onboard sensors, including a microphone. Training a machine learning model might seem daunting to many people, but online services like Edge Impulse makes the process very beginner-friendly. Once you start training your own models for specific applications, you quickly learn that building and maintaining a high quality dataset is often the most time-consuming part of machine learning. Fortunately for this use case, a massive online library of bird calls from all over the world is available on Xeno-Canto. This can be augmented with background noise from the area where the device will be deployed to reduce false-positives. Edge Impulse will train the model using the provided dataset, and generate a library that can be used on the Arduino with one of the provided sample sketches to log and send the collected data to a server. Then comes the never ending process of iteratively testing and improving the recognition model. Edge Impulse is also compatible with more powerful devices such as the Raspberry Pi and Jetson Nano if you want more intensive machine learning models.

We’ve also seen the exact same setup get used for smart baby monitor. If you want to learn more, be sure to watch at [Shawn Hymel]’s talk from the 2020 Remoticon about machine learning on microcontrollers. Continue reading “Recognising Bird Sounds With A Microcontroller” →

Evan Doorbell’s Telephone World

July 6, 2021 by Jonathan Bennett 19 Comments

Ah, phone phreaking. Some of us are just old enough to remember the ubiquity of land lines, but just young enough to have missed out on the golden years of phreaking. There’s something nostalgic about the analog sounds of the telephone, and doubly so when you understand what each click and chunk sound means. If this wistful feeling sounds familiar, then you too will appreciate [Evan Doorbell] and his recordings of 1970s telephone sounds. He’s been slowly working through his old recordings, and compiling them into a series of narrated tours of the phreak subculture.

[Evan]’s introduction to exploring the phone system started from a misdialed number, and an odd message. He describes that recorded “wrong number” message as being very different from the normal Ma Bell messages — this one was almost sultry. What number did he have to dial to hear that unique recording again? What follows is a youth spent in pursuit of playing with the phone system, though it would be more accurate to say the “phone systems”, as discovering the differences between the various local phone exchanges is a big part of the collection. Check out the first tape in the series after the break.
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See-Through Carburetor Gives A Clear Demonstration

July 6, 2021 by Danie Conradie 19 Comments

Carburetors have been largely phased out on most automobiles, but for a century they were the standard, and still are on many smaller engines. Armed with a high-speed camera and with the help of his father, [Smarter Every Day] investigates these devices by experimenting with a DIY see-through carburetor connected to a real engine.

The purpose of a carburetor is to mix gasoline and oxygen to the correct ratio for combustion inside the engine. Gasoline flow from the tank to the bowl, from where gets sucked into the venturi. The choke valve adjusts the amount of air entering the carb, while the throttle controls the amount of air-fuel mixture entering the engine. It appears that the carburetor was made from a resin 3D printed body and manifold, with an acrylic cover and PLA throttle and choke valves. It was attached to a single-cylinder engine.

The high-speed footage is incredible, and clearly shows the operation of the carburetor and makes it incredibly easy to understand. If you’re interested, he also uploaded a second video with almost 80 minutes of detailed footage.

[Smarter Every Day]’s infectious curiosity has led to numerous fascinating projects, including a supersonic baseball canon and the backward bicycle.

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E-Paper Pocket Map Goes Where Your Phone Can’t

July 6, 2021 by Tom Nardi 47 Comments

It’s easy to take for granted the constantly-connected, GPS-equipped, navigation device most of us now carry in our pockets. Want to know how to get to that new restaurant you heard about? A few quick taps in Google Maps, and the optimal route given your chosen transportation method will be calculated in seconds. But if you ever find yourself lost in the woods, you might be in for a rude awakening. With no cell signal and a rapidly dwindling battery, that fancy smartphone can quickly end up being about as useful as a rock.

Enter the IndiaNavi, a modernization of the classic paper map that’s specifically designed to avoid the pitfalls that keeps your garden variety smartphone from being a reliable bushcraft tool. The color electronic paper display not only keeps the energy consumption low, but has unbeatable daylight readability. No signal? No problem, as the relevant maps are pre-loaded on the device.

Besides the 5.65 inch e-paper display from Waveshare, the India Navi features a L96 M33 GPS receiver and ESP32-WROOM-32 microcontroller. The 3D printed enclosure that holds the electronics and the lithium pouch battery that powers them is still in the early stages, but we like the book-style design. The focus on simplicity and reliability doesn’t end with the hardware, either. The software is about a straightforward as it gets: just boot the IndiaNavi and you’re presented with a map that shows your current position.

With the rise of easily hackable e-paper displays, we’re excited to see more concepts like the IndiaNavi which challenge our ideas on how modern electronics have to function and be used.

USB Power Bank’s Auto-Off Becomes Useful Feature In Garage Door Remote

July 6, 2021 by Donald Papp 10 Comments

For devices that are destined for momentary and infrequent use as well as battery power, some kind of power saving is pretty much a required feature. For example, when [PJ Allen] turned two ESP8266-based NodeMCU development boards into a replacement wireless remote garage door opener, a handy USB power bank ended up serving as a bit of a cheat when migrating the remote away from the workbench. Instead of moving the board from USB to battery power and implementing some kind of sleep mode or auto-off, [PJ Allen] simply plugged in a USB power bank and let it do all the work.

This is how the feature works: some USB power banks turn themselves off unless they detect a meaningful current draw. That means that if the power bank is charging a phone, it stays on, but if it’s only lighting up a few LEDs, it’ll turn itself off. This feature can be a frustrating one, but [PJ Allen] realized that it could actually be useful for a device like his garage door remote. Turning on the power bank delivers 5 V to the NodeMCU board and allows it to work, but after about fifteen seconds, the power bank turns itself off. Sure, strapping a power bank to the remote makes the whole thing bigger than it needs to be, but it’s a pretty clever use of the minimum load as an effortless auto-off feature.

The NodeMCU boards in [PJ Allen]’s DIY remote use ESP-NOW for their wireless communications, a nifty connectionless protocol from Espressif that we’ve seen used in other projects as well, such as this ESP32-based walkie-talkie.