[Jason] has continued to plug along with his sonar build and recently showed up a monostatic active sonar using a piezo element and microphone. Regular readers will remember [Jason’s] experiments from a Fail of the Week post which focused on his water-proofing woes from a much earlier prototype.
We find this offering far more engaging. He has ditched the ultrasonic module seen in those experiments. The new rig drives the piezo element using a 27V source. After each ping is sent out, the microphone input is immediately captured to detect the return of the audible sound. [Jason] mentions that the TI Launchpad he’s using for the project is fast enough for these experiments but he may switch to a Teensy 3.1 in order to double the RAM and thereby increase the sample size he is able to record.
Of course this is intended for underwater ROVs so his next iteration will involve a DIY hydrophone. We can’t wait to see that one as the process of converting this test rig into one that works underwater evades us. If you have some tips on that topic please let us know in the comments.
Continue reading “Sonar Built from Piezo and Microphone”
LVBots, a club for robot building enthusiasts in Las Vegas, held an open house the week of CES. This was the only trip [Sophi] and I took away from the conference halls of The Strip and it was a blast! The group holds meetings twice a month in a space provided by Pololu — a well-known robotics and electronics manufacturer headquartered just south of McCarran International Airport.
[Claire] demonstrating robotic closet demo and app
The mechanized racks of the automated closet
Line-following robot demonstration
Sumo robots about to rumble
Before the formal part of the gathering started there were several builds being shown off. [Claire] and [Brian] recently participated in an AT&T sponsored hackathon. Their creation is a robotic closet. The system involves moving racks of clothing which are tracked by a smartphone app. Interesting features discussed for the software include monitoring when each garment was last worn, last washed, and if it is appropriate for current weather conditions. Dig into the code in their repo.
In other parts of the room a pair of line-following robots did their thing, and a couple of sumo-bots competed to push each other out of the ring. A large group was gathered around the projector watching videos of robots of all types, brainstorming about the difficult parts, how they were overcome, and how these methods may be applied to their own build. I can attest that hanging with a group of people who are trying to cue up the most amazing robot demonstrations makes for amazing viewing!
As the organized part of the meeting began I was delighted to hear about a standing challenge from the LVbots group. The Tabletop challenge has multiple phases that serve to encourage builders to start modestly and then iterate to achieve new goals:
Phase 0: bring a robot to LVBots
Phase 1: travel back and forth without falling off
Phase 2: find an object and push it off
Phase 3: push object into a goal
[Nathan Bryant] and robot
[Joe Carson] and robot
[Nathan Bryant] was one of the two robot builders trying out the challenge on this night. He built this hexapod from balsa wood and three servo motors and was testing Phase 1. The bot includes a sensor dangling out in front of the robot to detect then the table surface is no long below. At that point it backs up a few steps, turns in place, and proceeds in the opposite direction. [Nathan] mentions that he worked out all the movements in a spreadsheet and that future firmware upgrades will dramatically increase the speed at which the bot moves. We love the audible cadence of the bot which is easily observed in the video above. At one point a leg dangles over the edge and it looks like [Nathan] pushed the bot back but I don’t remember him actually touching it so I’m calling this a trick of camera angle.
One phase further in the Tabletop Challenge is [Joe Carson]. He exhibited a wheeled robot he’s been working on that includes a gripper arm on the front. The robot looks around the table for a predefined color, in this case provided by a highlighting marker. When found the bot approaches, grips, and then proceeds to move the marker over the void where it is dropped out of existence; at least from the robot’s point of view.
We ran into [Paul Allen] at CES. He was showing off Sigzig, a super-low noise data logger which his company is just rolling out.
A couple of years ago he worked on a standalone chemical sensor and had a few extra boards sitting around after the project was done. As any resourceful hacker will do, he reached for them as the closest and easiest solution when needing to log data as a quick test. It wasn’t for quite some time that he went back to try out commercially available loggers and found a problem in doing so.
The performance of off-the-shelf data loggers wasn’t doing it for [Paul’s] team. They kept having issues with the noise level found in the samples. Since he had been patching into the chemical sensor PCBs and getting better results, the impetus for a new product appeared.
The flagship 24-bit 8-channel Sigzig samples 0-5v with less than 1uV of noise. A less expensive 4-channel differential unit offers 18-bit with 10-12 uV of noise. They are targeting $199 and $399 price points for the two units. We asked about the sample rate in the video below. The smaller version shown here captures up to 240 samples per second. The big guy has the hardware potential to sample 30,000 times per second but
since the data is continuously streaming over USB that rate is currently limited to much less.
Update: It has been pointed out in the comments that USB may not be the choke point for sample rate.
Hurry! Carve out your Hackaday.io homestead with a vanity URL. You can see I’ve already secured hackaday.io/mike, but get in before the rest of Hackaday finds out and you can you have ‘/tom’, ‘/jane’, or ‘/zerocool’. (Don’t do it… you can be more creative than zerocool!)
Whether you already have an account, or if you want to create one right now, the next time you log into Hackaday.io the interface will give you the opportunity to choose your vanity address. Like the Oklahoma land rush, we’re sure there will be a swell of folks looking to squat on the most pristine land. So if your first name is already taken, now is the perfect time to re-invent your perfect username.
For those that need a jump start picking their slug, we want to hear your favorite screen name/handle/user alias of all time in the comments. At the risk of embarassing [Jeff Keyzer], I have to say his alias (and company name) Mighty Ohm is pretty spectacular. Can anyone beat it?
Here’s your chance to grab a tangible piece of Hackaday. This morning we are starting pre-orders for the Hackaday Omnibus 2014. This is our first-ever print edition. It collects some of the best original content published on Hackaday in 2014.
We’re proud of what the Hackaday crew accomplished last year. From stories of old and new to articles that encouraged you to stretch your hacking universe, we are thrilled with the original content articles we saw published last year. To go along with this top-tier content, we added amazing art and illustrations from [Joe Kim]. The product is something that demands commemoration in print and thus the Omnibus was born.
This full-color, 80 page, perfect binding volume is just what your coffee table has been crying out for. Of course it will look spectacular covered in solder and clipped resistor leads on the bench. And if your company is serious about hardware you need to send that message with a copy of the Omnibus in the reception area (or comically in the commode).
We are pricing the Hackaday Omnibus 2014 at $15 but we will sweeten the deal if you get in on the preorder. Use this coupon code to get $5 off: OMNIBUS2014. The coupon will work for the first 500 copies pre-ordered with an estimated shipping date of 2/9/15.
[Gaurav Taneja] was showing off his projection clock add-on for iPhone called Clockety at this year’s Consumer Electronics Show. The concept is pretty neat, a clip-on clock which uses the iPhone flash LED as the light source. It may sound a little gimmicky until you see the functionality of the accompanying app which is shown off in the video after the break. Once clipped onto the phone, you lay it face down on your night stand and a gentle tap on the furniture will turn the projection on or off. This is a killer feature when you’re staying some place without an illuminated bedside clock.
Continue reading “Clockety Uses Phone Flash for Projection Clock”
Flip-dot displays are grand, especially this one which boasts 74,088 pixels! I once heard the hardware compared to e-ink. That’s actually a pretty good description since both use a pixel that is white on one side and black on the other, depend on a coil to change state, and only use electricity when flipping those bits.
What’s remarkable about this is the size of the installation. It occupied a huge curving wall on the ooVoo booth at 2015 CES. We wanted to hear more about the hardware so we reached out to them they didn’t disappoint. The ooVoo crew made time for a conference call which included [Pat Murray] who coordinated the build effort. That’s right, they built this thing — we had assumed it was a rental. [Matt Farrell] recounts that during conception, the team had asked themselves how an HD video chat for mobile company can show off display technology when juxtaposed with cutting edge 4k and 8k displays? We think the flip-dot was a perfect tack — I know I spent more time looking at this than at televisions.
Join us after the break for the skinny on how it was built, including pictures of the back side of the installation and video clips that you have to hear to believe.
Continue reading “The Giant Flip-Dot Display at CES”