Cheap, Full-Duplex Software Defined Radio With The LimeSDR

A few years ago, we saw the rise of software-defined radios with the HackRF One and the extraordinarily popular RTL-SDR USB TV tuner dongle. It’s been a few years, and technology is on a never-ending upwards crawl to smaller, cheaper, and more powerful widgets. Now, some of that innovation is making it to the world of software-defined radio. The LimeSDR Mini is out, and it’s the cheapest and most capable software defined radio yet. It’s available through a Crowd Supply campaign, with units shipping around the beginning of next year.

The specs for the LimeSDR mini are quite good, even when compared to kilobuck units from Ettus Research. The frequency range for the LimeSDR Mini is 10 MHz – 3.5 GHz, bandwidth is 30.72 MHz, with a 12-bit sample depth and 30.72 MSPS sample rate. The interface is USB 3.0 (the connector is male, and soldered to the board, but USB extension cables exist), and the LimeSDR is full duplex. That last bit is huge — the RTL-SDR can’t transmit at all, and even the HackRF is only half duplex. This enormous capability is thanks to the field programmable RF transceiver found in all of the LimeSDR boards. We first saw these a year or so ago, and now these boards are heading into the hands of hackers. Someone’s even building a femtocell out of a Lime board.

The major selling point for the LimeSDR is, of course, the price. The ‘early bird’ rewards for the Crowd Supply campaign disappeared quickly at $99, but there are still plenty available at $139. This is very inexpensive and very fun — on the Crowd Supply page, you can see a demo of a LimeSDR mini set up as an LTE base station, streaming video between two mobile phones. These are the golden days of hobbyist SDR.

Better Stepping With 8-Bit Micros

The electronics for motion control systems, routers, and 3D printers are split into two camps. The first is 8-bit microcontrollers, usually AVRs, and are regarded as being slower and incapable of cool acceleration features. The second camp consists of 32-bit microcontrollers, and these are able to drive a lot of steppers very quickly and very smoothly. While 32-bit micros are obviously the future, there are a few very clever people squeezing the last drops out of 8-bit platforms. That’s what the Buildbotics team did with their ATxmega chip — they’re using a clever application of DMA as counters to drive steppers.

The usual way of driving steppers quickly with an ATMega or other 8-bit microcontroller is abusing the hardware timers. It’s quick, but there is a downside. It takes time for these timers to start and stop, and if you’re doing it two hundred times per second with four stepper motors, that clock jitter will ruin your CNC machine. The solution is to use a DMA channel to count down, with each count sending out a pulse to a stepper. It’s a clever abuse of the hardware, and the only drawback is the micro can’t send more than 2¹⁶ pulses per any 5ms period. That’s not really an issue because that would mean some very, very fast acceleration.

The Buildbotics team currently has a Kickstarter running for their four-axis CNC controller using this technique. It’s designed for Taig mills, 6040 routers, K40 lasers, and other various homebrew robots. It’s an interesting solution to the apparent end of the of the age of 8-bit microcontrollers in CNC machines and certainly worth checking out.

False Claims On Kickstarter: What’s New?

Kickstarter and its ilk seem like the Wild West when it comes to claims of being “The world’s most (Insert feature here) device!” It does add something special when you can truly say you have the world record for a device though, and [MellBell Electronics] are currently running a Kickstarter claiming the worlds smallest Arduino compatible board called Pico.

We don’t want to knock them too much, they seem like a legit Kickstarter campaign who have at time of writing doubled their goal, but after watching their promo video, checking out their Kickstarter, and around a couple of minutes research, their claim of being the world’s smallest Arduino-compatible board seems to have been debunked. The Pico measures in at an impressive 0.6 in. x 0.6 in. with a total area of 0.36 which is nothing to be sniffed at, but the Nanite 85 which we wrote up back in 2014 measures up at around 0.4 in. x  0.7in. with a total area of around 0.28 In this post-fact, fake news world we live in, does it really matter? Are we splitting hairs? Or are the Pico team a little fast and loose with facts and the truth?

There may be smaller Arduino compatible boards out there, and this is just a case study between these two. We think when it comes to making bold claims like “worlds smallest” or something similar perhaps performing a simple Google search just to be sure may be an idea.

Continue reading “False Claims On Kickstarter: What’s New?”

Friday Hack Chat: Crowd Supply

Crowdfunding is a mixed bag, at best. On one hand, you have fantastically successful products like Pebble, Oculus, and the Kano personal computer that managed to take in money, turn out a product, and become a successful company. (If even just for a while, the Pebble was great.) On the other hand, you have obvious scams like a color-picking pen that are run by a literal Nigerian scammer.

Crowd Supply is different. Unlike other crowdfunding platforms, to get on Crowd Supply you’ll need a working prototype. Where other platforms can measure their success by how many campaigns were successfully funded, and how many of those campaigns successfully delivered rewards to backers, I’m not aware of any Crowd Supply campaigns that have ever failed completely.

For this week’s Hack Chat, we’ll be talking with [Josh Lifton], CEO of Crowd Supply. Topics will include determining if there’s a market for your product, the ins and outs of fulfillment, to shipping your product. We’re taking questions from the community, and there’s a question sheet we’ll be reading from.

Josh has a PhD from the MIT Media Lab and holds a BA in physics and mathematics from Swarthmore College. Prior to Crowd Supply, Josh worked in a variety of technology settings, from instrumenting thousands of audience members with custom wearable computers for a Cirque du Soleil performance to, most recently, serving as head of engineering at Puppet Labs.

Here’s How To Take Part:

join-hack-chatOur Hack Chats are live community events on the Hack Chat group messaging. This Hack Chat will take place at noon Pacific time on Friday, July 28th. Confused about where and when ‘noon’ is? Here’s a time and date converter!

Log into, visit that page, and look for the ‘Join this Project’ Button. Once you’re part of the project, the button will change to ‘Team Messaging’, which takes you directly to the Hack Chat.

You don’t have to wait until Friday; join whenever you want and you can see what the community is talking about.

Hackaday Links: May 28, 2017

Boeing and DARPA are building a spaceplane. Right now it’s only a press release and a few concept images, but it looks like this is an air-launched system kind of like a Tristar/Pegasus, only much higher and completely unmanned. It’s a ton and a half to low earth orbit, with a goal of 10 flights in 10 days.

Up in Albany? There’s a new hacker con happening in a few weeks. Anycon is a hacking, infosec, and cyber security conference happening June 16 & 17th in Albany, NY. The organizers of this con ([Chris], and his company Leet Cybersecurity) are loosely modeling this con after Derbycon. [Dave Kennedy] of TrustedSec will be attending as the keynote speaker.

GOOD NEWS! [Casey Neistat] is under investigation by the FAA. [Casey Neistat] is the YouTuber that flies drones right in the middle of the Hudson River corridor, and is a menace to general aviation around NYC.

This is neat. The Supplyframe Design Lab is the Hackaday Mothership right in the middle of Pasadena where we host our designers in residence, host a few meetups, and slowly fill every cubic inch of space with either dust or tools. The Design Lab just won a design award. You can check out the ‘design’ part of the Design Lab here, but keep in mind it will never be that clean ever again.

Here’s an interesting Twitter to follow. Alitronik is a curator of the weird and wonderful cheap crap that can be found on AliExpress. Need an Altera Cyclone dev board? Here you go. A desk-mountable OLED inspection microscope? Done. A seven dollar Tesla coil? Dude, you can totally fit this inside a hat.

[Drygol] had a nice old Commodore C16 with a broken TED chip. A shame, really. He did what anyone would do: put a C64 motherboard in the case for a fancy stealth upgrade.

Is the great crowdfunded 3D printer boom over? Some would say that ship sailed after dozens of 3D printer crowdfunding projects failed to deliver, or delivered very low-quality machines. These people were wrong. This Polaroid-branded 3D printing pen might not get funding. A year ago, this project would have been funded on day one. There would have been writeups in The Verge on how Polaroid is turning the corner after decades of wasted opportunities. Now, the Crowdfunded 3D printer boom is finally over.

The Hackaday crew was at the Bay Area Maker Faire last weekend and holy crap did we have a blast. Everyone came to the meetup on Saturday except for the fire marshall. The secret OSHPark bringahack on Sunday was even more impressive. We also saw a Donkey Car capable of driving around a track autonomously, but the team behind it didn’t have their work up on the Internet at the time.

A Simple, Easy To Use ESP32 Dev Board

The ESP32 is Espressif’s follow-up to their extraordinarily popular ESP8266 WiFi chip. It has a dual-core, 32-bit processor, WiFi, Bluetooth, ADCs, DACs, CAN, a Hall effect sensor, an Ethernet MAC, and a whole bunch of other goodies that make this chip the brains for the Internet of Everything. Everyone has been able to simply buy an ESP32 for a few months now, but the Hackaday tip line isn’t exactly overflowing with projects and products built around this wonderchip. Perhaps we need an ESP32 dev board or something.

The Hornbill is the latest crowdfunding campaign from CrowdSupply. It’s an ESP32 dev board, packed with the latest goodies, a single cell LiPo charger, and a USB to serial chip that will probably work with most operating systems. The Hornbill comes in two varieties, a breadboardable module, with a breakout board that includes an SD card slot, sensors, an RGB LED, and a bunch of prototyping space. The second version is something like an Adafruit Flora with big pads for alligator clips.

While this isn’t the first ESP32 breakout we’ve seen — Adafruit, Sparkfun, and a hundred factories in China are pumping boards with this chip out — it is a very easy and inexpensive way to get into the ESP32 ecosystem.

A Wireless Oscilloscope Isn’t As Dumb As It Sounds

The latest CrowdSupply campaign is a wireless, Bluetooth oscilloscope that doesn’t make a whole lot of sense until you really think about it. Once you get it, the Aeroscope wireless oscilloscope is actually a pretty neat idea.

If the idea of battery-powered, Bluetooth-enabled test and measurement gear sounds familiar, you’re not dreaming. The Mooshimeter, also a project on CrowdSupply, is a multichannel multimeter with no buttons, no dial, and no display. You use the Mooshimeter through an app on your phone. This sounds like a dumb idea initially, but if you want to measure the current consumption of a drone, or under the hood of your car while you’re driving, it’s a really, really great idea.

The specs of the Aeroscope aren’t bad for the price. It is, of course, a one-channel scope with 20 MHz bandwidth and 100Msps. Connection to the device under test is through pokey bits or grabby bits that screw into an SMA connector, and connection to a display is over Bluetooth 4.0. You’re not getting a scope that costs as much as a car here, but you wouldn’t want to put that scope in the engine bay of your car, either.

The Aeroscope is currently on CrowdSupply for $200. Compared to the alternatives, that’s a bit more than the no-name, USB scopes. Then again, those are USB scopes, not a wireless, Bluetooth-enabled tool, and we can’t wait to see what kind of work this thing enables.