Tutorial For Setting Up Raspberry Pi For Ham Radio Use

September 8, 2020 by 9 Comments

There was a time when a ham radio set up sported many dials and switches and probably quite a few boxes as well. Computers have changed all that. Some transceivers now have just a few buttons or are even totally computer-controlled. Where a ham, at one time, might have a TeleType machine, a slow-scan TV monitor, and a fax printer for receiving satellite images, now that can all be on a single computer which can even be a Raspberry Pi. [F4GOH] has a post that takes you from the fundamentals to installing everything from an SDR to many common ham programs for digital modes, APRS, SSTV, and more. You can download the seven-part tutorial as separate PDF files, too.

Even if you aren’t a ham, you might find some of the software interesting. OpenWebRX lets you listen to your software defined radio on the road. You can use other software to pick up weather satellite data.

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Measure 1024 Times, Cut Once

September 8, 2020 by 25 Comments

Typically, someone’s first venture into coding doesn’t get a lot of attention. Then again, most people don’t program a CNC table saw right out of the gate. [Jeremy Fielding] wasn’t enticed with “Blink” or “Hello, world,” and took the path less traveled. He tackled I/O, UX, and motion in a single project, which we would equate to climbing K2 as a way to get into hiking. The Python code was over 500 lines, so we feel comfortable calling him an over-achiever.

The project started after he replaced the fence on his saw and wondered if he could automate it, and that was his jumping-on point, but he didn’t stop there. He automated the blade height and angle with stepper motors, so the only feedback is limit switches to keep it from running into itself. The brains are a Raspberry Pi that uses the GPIO for everything. There is a manual mode so he can use the hand cranks to make adjustments like an ordinary saw, but he loses tracking there. His engineering background shines through in his spartan touchscreen application and robust 3D model. The built-in calculator is a nice touch, and pulling the calculations directly to a motion axis field is clever.

We’ve covered [Jeremy]’s DIY dynamometer and look forward to whatever he builds next. Until then, check out a light-duty approach to CNC that cuts foam in two-and-a-half dimensions.

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Electric Surfboard Doesn’t Need Waves

September 8, 2020 by 20 Comments

Surfing is a majestic sport, but one which relies heavily on the environment to provide suitable waves for the practice. If you don’t live near the right piece of coast, you’re simply out of luck. Of course, you could always build yourself an electric board instead to tear up the local lakes – and that’s precisely what [Simon] did. 

Following on from earlier experiments with 3D printed boats, the board is powered by a pair of jet drives, sourced from [YOUNGSTERS JETS]. Not one to skimp on horsepower, [Simon] selected twin 5000W motors to provide plenty of motive power. Of course, operating at such power levels comes with some headaches, and there’s plenty of blown ESCs and damaged motors along the way. Perseverance and plenty of cash outlay later, and the board is out carving elegant lines in the water at over 45 km/h.

Future updates aim to solve the problem of water ingress into the electronics, particularly the hand controller, of which [Simon] has already ruined two. We look forward to seeing more of these craft out in the water in coming days, particularly as they’re at least 30% less loud and annoying than the common jetski. Video after the break.

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Identifying Creatures That Go Chirp In The Night

September 8, 2020 by 26 Comments

It’s common knowledge that bats navigate and search for their prey using echolocation, but did you know that the ultrasonic chips made by different species of bats are distinct enough that they can be used for identification? [Tegwyn☠Twmffat] did, which is why he came up with this impressive device capable of cataloging the different bats flying around at night.

Now this might seem like an odd gadget to have, but if you’re in the business of wildlife conservation, it’s not hard to imagine how this sort of capability might be useful. This device could be used to easily estimate the size and diversity of bat populations in a particular area. [Tegwyn☠Twmffat] also mentions that, at least in theory, the core concept should work with other types of noisy critters like rodents or dolphins.

Powered by the NVIDIA Jetson Nano, the unit listens with a high-end ultrasonic microphone for the telltale chirps of bats. These are then processed by the software and compared to a database of samples that [Tegwyn☠Twmffat] personally collected in local nature reserves. In the video after the break, you can also see how he uses a set of house keys jingling as a control to make sure the system is running properly.

As winner of the Train All the Things contest back in April, we’re eager to see how the Intelligent Wildlife Species Detector will fare as the competition heats up in the 2020 Hackaday Prize.

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Size Does Matter When It Comes To SD Cards

September 8, 2020 by 54 Comments

The SD card first burst onto the scene in 1999, with cards boasting storage capacities up to 64 MB hitting store shelves in the first quarter of 2000. Over the years, sizes slowly crept up as our thirst for more storage continued to grow. Fast forward to today, and the biggest microSD cards pack up to a whopping 1 TB into a package smaller than the average postage stamp.

However, getting to this point has required many subtle changes over the years. This can cause havoc for users trying to use the latest cards in older devices. To find out why, we need to take a look under the hood at how SD cards deal with storage capacity. Continue reading “Size Does Matter When It Comes To SD Cards” →

Designing Hardware Challenges Hack Chat

September 8, 2020 by 1 Comment

Join us on Wednesday, September 9 at noon Pacific for the Designing Hardware Challenges Hack Chat with Michelle Thompson!

Michelle is deeply involved in designing the virtual CTF challenge for this month’s GNU Radio Conference. Her experience includes dreaming up both in-person and virtual “Capture the Flag” style challenges that span both hardware and software. It’s fun to compete and a powerful way to learn, but how do you choose the hardware and dial-in the scope and difficulty for each part of the challenge? Join us for the chat as Michelle walks through how she builds great challenges.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, September 9 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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A Backlit Calendar For All Eternity

September 8, 2020 by 7 Comments

The advantage of the irregularities in the Gregorian calendar combined with the seven-day week is that they provide a constant source of yearly revenue for the paper calendar industry. Long before sustainability became a trending topic, people invented reusable, perpetual calendars, but the non-digital versions of these are sometimes complicated tables that are hard to interpret. [andrei.erdei] created an automated perpetual calendar that is mostly hardware but uses some digital tricks to overcome these problems.

The calendar consists of sandwiched panels of smoked acrylic which are backlit by some strips of WS2812Bs. Although the panels could have been processed with a laser cutter, [andrei.erdei] used a CNC which gave him the possibility to mill some grooves in the back panel to hold the LED strips. The stencil for the numbers was simply printed out on paper and the background made opaque by printing several times over the same piece of paper. The electronics consist of an ESP8266 which takes the date from an NTP server and lights up the corresponding LEDs in different colors for weekdays and weekends.

The classic version of this type of perpetual calendar uses a sliding frame but we have also seen completely different versions based on moving gears.

Video after the break.

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