Track Satellites With A 2-axis Antenna Positioner

Ham radio operators are curious beasts. They’ll go to great lengths to make that critical contact, and making sure their directional antennas are pointing the right way can be a big part of punching through. Of course there are commercial antenna rotators out there, but hams also like to build their own gear, like this Raspberry Pi-controlled 2-axis rotator.

[wilho]’s main motivation for this build seems to have been the sad state of the art in commercial 2-axis rotators, which seems firmly mired in the 90s. Eschewing the analog pot sensors on DC brushed motors that seem to dominate the COTS market, [wilho] went with steppers and stout gearboxes for the moving gear. Feedback on the axes comes from 10-bit absolute encoders, and an MPU9250 9-axis IMU makes sure he knows exactly where the antenna is pointing with respect to both compass heading and elevation. A mast-mounted Rasp Pi controls everything and talks through a REST API to custom software that can return the antenna to custom set-points or track the moon, satellites, or the ISS. It’s a very impressive bit of kit that’s sure to drive your home-owners association bonkers.

For another 2-axis antenna positioner, check out 2015 Hackaday Prize finalist SATNOGS.

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ESP-Micro Is A Tiny Development Board

The ESP-8266 packs a lot of networking power into a small package. Some would say too small, which is why they often come on a slightly larger carrier PCB. The PCB is usually little more than a breakout with an optional 3.3V regulator. [Frazer Barnes] went one step further: he put an equally tiny USB to serial bridge, an oscillator, and some power management on an ESP-8266 breakout board.

You can program the ESP-8266 via the serial port, so having a built-in USB port is handy. Of course, you might not need it in the final product, but with the board being 25x30mm, you can probably cram it into most projects. [Frazer] posted a bit about the project on Hackaday.io, and has a GitHub project, although right now the upload of the design files is pending.

There’s no shortage of ESP-8266 projects. We saw a small Zigbee to ESP8266 board last year, and also the antidote for a tiny carrier board that includes an LCD, switches, and more. We also have tons of breakouts on Hackaday.io: here’s one with all the bells and whistles, and a similar, stripped-down version. All open-everything, and ready to go.

Cleanest Rasberry Pi NES Mod

[ModPurist] sent us his Raspberry-Pi-in-a-Nintendo casemod. Before you go hitting the back button, this is a good one because it’s so well executed. And it’s actually a two-fer: he’d previously built up a wireless NES controller that completes the setup.

7058802Both of these mods are hacks in the purest sense of the word. The controller mod took a wireless keyboard’s sending circuit board and wedged it inside the NES controller. The original NES controller reads out the buttons into a shift register and sends that down a wire. That’s all gone. [ModPurist] just wired up each button to the sender PCB and figured out which keys they corresponded to on the PC by pressing the buttons. Simple.

The best part of his video about building the controller? After about a minute in, he forgets that he’s filming a technical how-to video and plays Pokemon for the remaining four minutes. That’s the sign of success.

Then there’s the NES hack itself. He stripped everything out, added a Raspberry Pi 2 and a fan, made it all work with the power switch and the original TV outs, and it’s done. Again, nothing more than needs doing, but nothing less. It looks just right plugged up to the CRT monitor (from a C64, no less), and there’s no doubt that being able to play wirelessly on an original NES controller is cool.

This isn’t [ModPurist]’s first time here on Hackaday either, and his “Cold Boy” fridge-turned-Gameboy is a work of art.

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Kids And Hacking: Electromagnetic Eggs

One of my favorite things to do is visit with school kids who are interested in engineering or science. However, realistically, there is a limit to what you can do in a single class that might last 30 to 90 minutes. I recently had the chance to work with a former colleague, a schoolteacher, and The Teaching Channel to create an engineering unit for classroom use that lasts two weeks.

This new unit focuses on an egg drop. That’s not an original idea, but we did add an interesting twist: the project develops a “space capsule” to protect the egg, but also an electromagnetic drop system to test the capsules. The drop system allows for a consistent test with the egg capsule releasing cleanly from a fixed height. So in addition to the classic egg drop capsule, the kids have to build an electromagnet, a safe switching circuit, and a test structure. Better still, teams of kids can do different parts and integrate them into a final product, closely mimicking how real engineering projects work.

There are a few reasons for the complexity. First, given ten class sessions, you can do a lot more than you can in a single day. Second, I always think it is good if you can find exercises that will appeal to lots of different interests. In the past, I’ve used robots and 3D printers for that reason. Some students will be interested in the electronics, others in the mechanics, and still others will be interested in the programming. Some kids will engage in 3D modeling (robot simulation or 3D objects). The point is there is something for everyone.

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Microchip To Acquire Atmel For $3.56 Billion

Just last week, there was considerable speculation that Microchip would buy Atmel. The deal wasn’t done, and there was precedent that this deal wouldn’t happen – earlier this year, Dialog made an approach at Atmel. Now, though, the deal is done: Microchip will acquire Atmel for $3.56 Billion.

There are three main companies out there making microcontrollers that are neither ancient 8051 clones or ARM devices: TI’s MSP430 series, Microchip and Atmel. Microchip has the very, very popular PIC series microcontrollers, which can be found in everything. Atmel’s portfolio includes the AVR line of microcontrollers, which are also found in everything. From phones to computers to toasters, there’s a very high probablitiy you’re going to find something produced by either Atmel or Microchip somewhere within 15 feet of your person right now.

For the hobbyist electronic enthusiast, this has led to the closest thing we have to a holy war. Atmel chips were a little easier (and cheaper) to program, but were a little more expensive. Microchip’s chips have a very long history and proportionally more proper engineers who are advocates. PIC isn’t Arduino, though, a community that has built a large and widely used code base around the AVR family.

Microchip’s acquisition of Atmel follows several mergers and acquisitions in recent months: NXP and Freescale, Intel and Altera, Avago and Broadcom, and On Semiconductor and Fairchild. The semiconductor industry has cash and wants to spend it. What this means for the Atmel product line is left to be seen. The most popular micros probably won’t be discontinued, but if you’re using unpopular Atmel micros such as the ATtiny10 you might want to grab a reel or two before they’re EOL’d.

 

Sort Faster With FPGAs

Sorting. It’s a classic problem that’s been studied for decades, and it’s a great first step towards “thinking algorithmically.” Over the years, a handful of sorting algorithms have emerged, each characterizable by it’s asymptotic order, a measure of how much longer an algorithm takes as the problem size gets bigger. While all sorting algorithms take longer to complete the more elements that must be sorted, some are slower than others.

For a sorter like bubble sort, the time grows quadradically longer for a linear increase in the number of inputs; it’s of order O(N²).With a faster sorter like merge-sort, which is O(N*log(N)), the time required grows far less quickly as the problem size gets bigger. Since sorting is a bit old-hat among many folks here, and since O(N*log(N)) seems to be the generally-accepted baseline for top speed with a single core, I thought I’d pop the question: can we go faster?

In short — yes, we can! In fact, I’ll claim that we can sort in linear time, i.e a running time of O(N). There’s a catch, though: to achieve linear time, we’ll need to build some custom hardware to help us out. In this post, I’ll unfold the problem of sorting in parallel, and then I”ll take us through a linear-time solution that we can synthesize at home on an FPGA.

Need to cut to the chase? Check out the full solution implemented in SystemVerilog on GitHub. I’ve wrapped it inside an SPI communication layer so that we can play with it using an everyday microcontroller.

To understand how it works, join us as we embark on an adventure in designing algorithms for hardware. If you’re used to thinking of programming in a stepwise fashion for a CPU, it’s time to get out your thinking cap!

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Saving Old Voices By Dumping ROMs

Some people collect stamps. Others collect porcelain miniatures. [David Viens] collects voice synthesizers and their ROMs. In this video, he just got his hands on the ultra-rare Electronic Voice Alert (EVA) from early 1980s Chrysler automobiles (video embedded below the break).

Back in the 1980s, speech synthesis was in its golden years following the development of TI’s linear-predictive coding speech chips. These are the bits of silicon that gave voice to the Speak and Spell, numerous video game machines, and the TI 99/4A computer’s speech module. And, apparently, some models of Chrysler cars.

IMG_0695We tracked [David]’s website down. He posted a brief entry describing his emulation and ROM-dumping setup. He says he used it for testing out his (software) TMS5200 speech-synthesizer emulation.

The board appears to have a socket for a TMS-series voice synthesizer chip and another slot for the ROM. It looks like an FTDI 2232 USB-serial converter is being used in bit-bang mode with some custom code driving everything, and presumably sniffing data in the middle. We’d love to see a bunch more detail.

The best part of the video, aside from the ROM-dumping goodness, comes at the end when [David] tosses the ROM’s contents into his own chipspeech emulator and starts playing “your engine oil pressure is critical” up and down the keyboard. Fantastic.

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