Best Amazon Echo Dot Wall Mount Ever

I have 4 Echo Dots, plus a full size Echo in the living room. Love the durned little buggers, and calling out ‘alexa!’ has become a normal part of every day life. I use it for music, news, shopping lists, and home control of lights and dimmers. I can see the days of carrying on conversations with your house getting closer and closer.

The Dots are cute, but they need to sit on a surface somewhere. That takes up space and clutter. I’d been digging around to try and find a 3d printed mount or something similar so I could mount the Dots on the wall.

This morning while cleaning up my workbench, I realized there was a very simple way of hanging the dot on the wall. A pair of 3″ framing nails later, and voila. The dot is up and off my workbench, it’s stable, the speaker is cleared enough to be heard and sounds fine, victory.

I know many people dont’ have 2×6 studs exposed everywhere, but goshdarnit, this was a quicky fix that works great.

Creating Timelapse Videos from a Synology NAS

About a year and a half ago, I bought a Synology 216+ NAS .  The primary purpose was to do photography archiving locally (before syncing them up to Amazon S3 Glacier for long term storage).  The box has been a rock solid tool, and I’ve been slowly finding other uses for it.  It’s basically a fully functional Linux box with an outstanding GUI front end on it.

One of the tools included with the NAS is called ‘Surveillance Station’, and even though it has a fairly sinister name, it’s a good tool that allows control and viewing of IP connected cameras, including recording video for later review, motion detection, and other tidbits.  The system by default allows 2 cameras free, but you can add ‘packs’ that allow more cameras (these packs are not inexpensive – to go up to 4 cameras cost $200, but given this is a pretty decent commercial video system, and the rest of the software came free with the NAS, I opted to go ahead and buy into it to get my 4 cameras online).

It just so happens, in September, 2017, we had a contractor come on site and install solar panels on several houses within our community. What I really wanted to do is use the Synology and it’s attached cameras to not only record the installation, but do a timelapse of the panel installs. Sounds cool, right?

Here’s how I did it.

The Cameras

The first thing needed obviously were cameras. They needed to be wireless, and relatively easy to configure. A year or two ago, I picked up a D-Link DCS-920L IP camera. While the camera is okay (small, compact, pretty bulletproof), I was less than thrilled with the D-Link website and other tools. They were clunky and poorly written. A little googling around told me “hey, these cameras are running an embedded OS that you can configure apart from the D-Link tools”. Sure enough, they were right. The cameras have an ethernet port on them, so plugging that into my router and powering up let me see a new Mac address on my network. http://192.168.11.xxx/ and I got an HTTP authentication page. Logging in with the ‘admin’ user, and the default password of… nothing (!), I had a wonderful screen showing me all the configuration options for the camera. I’m in!

First thing, natch, I changed the admin password (and stored it in 1Password), then I set them up to connect to my wireless network. A quick rebooot later, and I had a wireless device I could plug into any power outlet, and I’d have a remote camera. Win!

Next, these cameras needed to be added to the Synology Surveillance Station. There’s a nice simple wizard in Surveillance Station that makes the adding of IP camera pretty straighforward. There’s a pulldown that lets you select what camera type you’re using, and then other fields appear as needed. I added all of my cameras, and they came up in the grid display no problem. This is a very well designed interface that made selecting, configuring, testing, and adding the camera(s) pretty much a zero-hassle process.

If you’re planning on doing time lapses over any particular length of time, it’s a good idea to go into ‘Edit Camera’ and set the retention timeperiod to some long amount of time (I have mine set to 30 days). This’ll give you enough room to record the video necessary for the timelapse, but you won’t fill your drive with video recordings. They’ll expire out automatically.

At this point you just need to let the cameras record whatever you’ll be animating later. The Synology will make 30 minute long video files, storing them in /volume1/surveillance/(cameraname).

For the next steps, you’ll need to make sure you have ssh access to your NAS. This is configured via Control Panel -> Terminal / SNMP -> Enable ssh. DO NOT use telnet. Once that’s enabled, you should be able to ssh into the NAS from any other device on the local network, using the port number you specify (I’m using 1022).

ssh -p 1022 shevett@192.168.11.100

(If you’re using Windows, I recommend ‘putty’ – a freely downloadable ssh client application.)

Using ‘ssh’ requires some basic comfort with command line tools under linux.  I’ll try and give a basic rundown of the process here, but there are many tutorials out on the net that can help with basic shell operations.

Putting It All Together

Lets assume you’ve had camera DCS-930LB running for a week now, and you’d like to make a timelapse of the videos produced there.

  1. ssh into the NAS as above
  2. Locate the directory of the recordings.  For a camera named ‘DCS-930LB’, the directory will be /volume1/surveillance/DCS-930LB
  3. Within this directory, you’ll see subdirectories with the AM and PM recordings, formatted with a datestamp.  For the morning recordings for August 28th, 2017 ,the full directory path will be /volume1/surveillance/DCS-930LB/20170828AM/.  The files within that directory will be datestamped with the date, the camera name, and what time they were opened for saving:
  4. Next we’ll need to create a file that has all the filenames for this camera that we want to time.   A simple command to do this would be:
    find /volume1/surveillance/DCS-930LB/ -type f -name '*201708*' > /tmp/files.txt

    This gives us a file in the tmp directory called ‘files.txt’ which is a list of all the mp4 files from the camera that we want to timelapse together.

  5. It’s a good idea to look at this file and make sure you have the list you want. Type
    pico /tmp/files.txt

    to open the file in an editor and check out out.  This is a great way to review the range of times and dates that will be used to generate the timelapse.  Feel free to modify the filename list to list the range of dates and times you want to use for the source of your video.

  6. Create a working directory.  This will hold your ‘interim’ video files, as well as the scripts and files we’ll be using
    cd 
    mkdir timelapse
    cd timelapse
  7. Create a script file, say, ‘process.sh’ using pico, and put the following lines into it.  This script will do the timelapse proceessing itself, taking the input files from the list creatived above, and shortening them down to individual ‘timelapsed’ mp4 files. The ‘setpts’ value defines how many frames will be dropped when the video is compressed. A factor of .25 will take every 4th frame. A factor of .001 will take every thousandth frame, compressing 8 hours of video down to about 8 seconds.
    #!/bin/bash
    
    counter=0;
    for i in `cat /tmp/files.txt`
    do
        ffmpeg -i $i -r 16 -filter:v "setpts=0.001*PTS" ${counter}.mp4
        counter=$((counter + 1))
    done
  8. Okay, now it’s time to compress the video down into timelapsed short clips.  Run the above script via the command ‘. ./process.sh’.  This will take a while.  Each half hour video file is xxx meg, and we need to process that down.  Expect about a minute per file, if you have a days worth of files, that’s 24 minutes of processing.
  9. When done, you’ll have a directory full of numbered files:
    $ ls
    1.mp4
    2.mp4
    3.mp4
  10. These files are the shortened half hour videos.  The next thing we need to do is ‘stitch’ these together into a single video.  ffmpeg can do this, but it needs a file describing what to load in.  To create that file, run the following command:

    ls *.mp4|sort -n| sed -e "s/^\(.*\)$/file '\1'/" > final.txt
  11. Now it’s time to assemble the final mp4 file.  The ‘final.txt’ file contains a list of all the components, all we have to do is connect them up into one big mp4.
    ffmpeg -f concat -safe 0 -i final.txt -c copy output.mp4
  12. The resulting ‘output.mp4’ is your finalized video.   If you’re working in a directory you can see from the Synology desktop, you can now play the video right from the web interface.  Just right click on it, and select ‘play’.

Here’s two of the three timelapses I did, using a remote camera in my neighbors house.  Considering the low quality of the camera, it came out okay…

This entire tutorial is the result of a lot of experimentation and tinkering.  There are holes, though.  For instance, I’d like to be able to set text labels on the videos showing the datestamp, but the ffmpeg that’s compiled on the NAS doesn’t have the text extension built into it.

Let me know if you have any suggestions / improvements / success stories!

Repairing Drone XT60 Power Connectors

A quicky post here. I took about a year and a half off drone racing, and I’m just getting back into it for a bit. What has happened during that time is that the community has moved onto to faster, smaller drones. At the moment all I have is my 250mm QAV250 clone, so keeping that flying until I build a new machine is what’s keeping me busy.

The damaged XT60

I went out to fly yesterday with some folks in Waltham, but before I could power up, I noticed my XT60 connector had broken loose on the positive lead. Bad news. That’s not something I can fix in the field. No flying for me!.
Tonight I sat down to repair the power connector, but realized I didn’t have any spares. I tried to reuse an old connector, and… well, melted it into goo. (that’s what’s int he alligator clips in the picture below). I had one other one, and managed to desolder and solder in the new connection without too much damage. I am sort of proud of the fact that I was able to reconnect the power leads, and add 3″ of extra silicone insulated feed wire, and get my shrink tubing in place without much chaos.

All fixed and insulated properly.

Tomorrow I should be able to fly with the MultiGP folks up in Derry, but I know my time with the 250 is coming to an end. I have a new frame and motor and battery setup in mind, but more on that when things get closer. For now, things are packed up and ready to go flying tomorrow!

Using Amazon Kindle Fire HD’s as Registration Terminals

Even though I’m not working on CONGO as much anymore, I’m still helping out with registration at a couple events, and I’m always looking for better tools and gear to use. I originally designed registration to use cheap, network bootable PC’s, but that was so 15 years ago. The new hotness are small, inexpensive tablets. So could you put together a registration environment using some cheap tablets? Sure.

I’m helping an event that’s using EventBrite for registration services. I’d helped out at a different event about a year ago, and was impressed with the tools Eventbrite offered. The best part was the Eventbrite Organizer, a mobile app for IOS and Android that basically gave you a live dashboard, but also allowed super-fast checkins using a QR code scan. Think of scanning a boarding pass when boarding an airplane. The process is very similar.

The only drawback was, I needed a series of tablets that were roughly the same (bringing batches of workstations that are all different is a sure way to headaches). I didn’t think buying a stack of iPads was going to make sense, and el cheapo tablets from ebay and amazon are sketchy.

3 Kindle Fires being configured as registration terminals
I saw a deal come across Woot for Amazon Fire HD 7″ Tablets for… $33. Each. After digging around on the net, it looked like it was possible to load non-amazon software on these, it just took a little bit of jiggling. I’ve rooted Android tablets before, but it’s not a pleasant experience. I was seeing documentation that allowed for the Play store to be activated without a lot of yak shaving, so I decided to go all in.

I ordered 3 of the tablets, and they arrived a few days later.

First impressions – these are really nice. The design and polish is excellent, they fit well in the hand, and have exceptional screens. They have excellent battery life, and front and rear facing cameras. For $33, there’s not much to go wrong with here.

Here’s the steps I went through to get them up to ‘useable’ status.

  • First, charge them up, natch. They have great batteries, and the entire upgrade process and installation can happen on battery, but really, just get ’em charged.
  • Next, power up and log into your Amazon account. All the Fires have to be tied to an amazon login. Using the same one on each is fine (Amazon supports many Kindles per account).
  • Continuously go into the System settings (swipe down from the top) and select Device Information -> System Update. There’s a good 6 full OS updates that have to happen to bring your device up to FireOS 5.3.x or later. This can take upwards of an hour and a lot of reboots, but at the end, you’ll have a fully upgraded device.
  • Next, we’re going need to install APK’s that are not ‘blessed’, so you have to tell the Fire to accept them. Go into settings -> Security settings and check the switch that says “Allow third party apps”
  • Download and install a file manager. I used ES-File Explorer, which is very popular, but I’ve seen others say “don’t use this it doesn’t work”. I suspect the ‘not working’ has since been fixed. It’s worked fine on 3 devices so far.
  • Next, pull down the APK’s via the Fire’s Silk Browser. Go to this thread on the XDA Developers forum and click on each of the APK links, and download the files, in order, from top to bottom.
  • Once they’re downloaded, start up the ES File Explorer, and navigate to the Downloads folder. You’ll see 4 APK’s there. Click on the them from RIGHT TO LEFT (which will install the ‘oldest’ one first, and the Play store last.
  • After each of the APK’s is installed, launch the Play store, log in with your Google account, and you are all set.

Now that the Fire can install third party apps via the Play store, all we needed to do is install Eventbrite Manager, and log into it with an access-limited login we created just for this event (we’re going to allow general joe schmoes to check people in, and having access to refunds, people’s personal infromation, etc – didn’t seem like a good idea. So a generic Eventbrite login that ONLY allows for checkins was created, and that’s what we logged the tablets into.

I also picked up a handful of desk mounts with really strong gooseneck stalks. Because we’re going to be scanning receipts via the rear camera, the tablet needs to be held off the desk easily.

And we’re done! The Eventbrite Manager app syncs the attendee list whenever it’s connected to the internet. So we can go ahead and check in people super-fast (with a very satisfying BADEEP whenever a successful scan happens), and not have to rely on hotel internet connectivity (which can be notoriously sketchy). At the end of the day, we have a full record of everyone who has checked in and when.

I Played With Lasers, and I Liked It

It’s no secret I’ve been having a great time hanging with the folks at MakeIt Labs in Nashua, NH. Many of the projects I’ve been working on have only been possible with their help and collaboration. Not in a “here lets do this for you” sense, but in providing a community where ideas can be bounced around, coupled with a physical space with every tool a geek could ever need at hand.

I’ve unofficially become the person organizing the parts supplies. These are ranks and ranks of bins that hold everything from capacitors to stepper motors to hot glue sticks to arcade pushbuttons. Understandably, these things can easily get out of control, so constant pruning and management is sort of a requirement. I can do that!

80w CO2 Laser in use
80w CO2 Laser in use
A new set of drawers we picked up are super-handy, but they’re just empty metal boxes. About 10″x12″x4″. Nice, useful, and stackable, but we tend to store lots of little parts, so we need to be able to divvy up that space a little more. We needed something like trays that could go into the drawers (which are all about the same size), to store small parts. The tray should be easily removable (take the tray out, use some of the parts, put it back), and easy to make many of them. We have about 120 drawers that need inserts. This sounds like a job for our 80w CO2 laser!

I had done some basic work on the laser, but this would be my first ‘build from scratch’. After measuring out the drawers, I decided to make a 9″square baseplate, with 4 sides, and a single divider down the middle that could easily be picked up. I used Adobe Illustrator to set where the cuts would be (Illustrator is great primarily because drawings measured in it translate perfectly to the laser cutter. No scaling / stretching problems. When I say ‘cut something 9″x9″‘, what I get is something 9″x9″.)

I manually did all the crenelations where the pieces would fit together. A fellow maker pointed out there’s software that helps do this, but for this first runthrough, I was okay doing it by hand. The material I was using is 1/8″ acrylic sheeting. Somewhere the lab picked up a metric buttload of the stuff, so we literally had dozens of square meters to work with.

First complete cut of the tray inserts.
First complete cut of the tray inserts.
Total cutting time was about 3 minutes. The laser had no problems working with the material. After removing the pieces from the machine and taping them together, I had a mocked up tray insert! Hooray!

It wasn’t all peaches and cream. I did mess up measurements on two of the tabs, and forgot to put in a cutoff for one small extension. After assembling what I’m referring to as the ‘1.0’ version, I realize there should be some changes. The central divider should tuck under the end pieces to give it better strength (it’s slotted in on the top now), and I should make a version of this that has 3 spaces in it, not just two. Tighter tolerances on the slots are needed (I measured 1/8″, but the ablation from the laser takes off a little bit more, so the slots are wider than they need to be).

Next step will be to re-do the cuts with the supporting tabs, remove the paper from the acrylic, and glue things together. If all goes well, I’ll have a nice insertable tray, and the ability to crank out many more without much work. Going full-on production of over a hundred of these trays will require an inventory of how much acrylic we have, and a decision on if we want to just pick up a few dozen sheets of 1/8″ birch (which would negate the ‘peeling off the paper’ problem).

I’ll post when there’s an updated sample. But for now… I played with lasers, and it was awesome.

Using a Raspberry Pi as a Realtime Voice Changer for Halloween

As most readers know, I’ve been working on my magic staff project for the last year and a half. I incorporated into the ‘Technomancer’ costume for Halloween and Arisia last year, and it was a big hit. I’m continuing to expand the costume, and one thing I’ve always wanted was a voice changer that would let me have a nice sepulchral voice to go with the creepy visage. My own voice from behind the mask is extremely muted, so it’s hard to carry on conversations or even talk to someone, so some external hookup was needed.

My 'bench' test run of the Pi with external USB sound board.
My ‘bench’ test run of the Pi with external USB sound board.

What surprised me was… no one had done this. I searched all over the web for realtime voice processing setups using a Raspberry Pi or Arduino, and while some folks had come close, no one (that I found) had put all the pieces together. So, it was time to do it!

The first component is naturally a Raspberry Pi. I used the pretty awesome CanaKit, which included lots of goodies (most importantly a good, solid case for the board, as well as a microSD card and other accessories). $69 was a great price.

Next, the Pi has onboard audio, but… well, it sucks. I needed separate mic input and outputs, and off-CPU sound processing. Fortunately, there’s huge numbers of these USB sound adapters going for less than $10 a pop. I got 2 just to be careful.

Pyle Audio portable PA
Pyle Audio portable PA

Next, I needed an amplifier. Something portable, loud, and with a remote microphone. This is one just for my setup. Obviously whatever you choose for your own project, pick whatever audio options you’d like. THe sound adapter has standard 1/8th” jacks for mic in and audio out, so just plug right in (I had a small problem with my Mic connection, in that the mic cable I used needed to be ‘out’ a quarter inch to connect properly. I used a small O-ring to keep the spacing proper). The amp I used is Pyle Pro PWMA50B ‘portable PA system’. At $29, it’s well worth it. Comes with a mic, built in rechargeable batteries, a belt mount, and, most importantly, an Auxiliary input.

Now comes the hard part. Getting the audio set up so it could handle recording and playing back in realtime required installing the ‘sox’, toolset, as well as all the alsa tools (most of ALSA comes with the Pi, but make sure they’re there). First, make sure you can play audio through the USB card to the PA. I used ‘aplay’ for this (this ALSA simple player), and a small WAV file I had lying around.

I also recommend running ‘alsamixer’ beforehand, to make sure you can see all the devices, and they’re not muted. ‘aplay -l’ and ‘arecord -l’ are handy in making sure you’re seeing everything you need.

Assuming you have working audio, now comes the fun part. Set up a sox pipe to read from the default audio device and write to the default audio device. Like this:

play "|rec -d"

If all goes well, you should be able to speak into the microphone, and have it come out the speaker. There will almost certainly be a delay of anywhere from a tenth to a half a second. There’s ways to mitigate that, but we’ll get to that in a minute.

If you have that path working, you’re 90% of the way done!

For my costume, I needed a deep voice, so I added -pitch -300 like this

play "|rec -d pitch -300"

I also had a problem with a very high pitched whine coming through the speakers, so I added a band filter to remove that (this syntax means “Remove sound centered on 1.2khz, with a bandwidth of 1.5khz on either side”) :

play "|rec -d pitch -300 band 1.2k 1.5k"

Only a little more tweaking, adding some echos, and I had the voice I wanted. The –buffer command shortens how much data is buffered for processing. This helped cut down the delay a bit, but runs the risk of buffer overruns if you talk a lot.

play "|rec --buffer 2048 -d pitch -300 echos 0.8 0.88 100 0.6 150 .5 band 1.2k 1.5k"

Here’s a sound sample of what it sounded like. Note this is before I added in the band filter, so you can hear the whine…
(direct link here)

The last thing needed was to have the changer start up when the pi reboots. I’m planning on carrying the Pi in a pouch on my belt, powered via one of those cell phone external battery packs. I can’t log in and start the tool whenever it boots. The fix is to put the ‘play’ and other amixer commands into a simple shell script (I put it in /root/setup.sh), and using the @reboot entry that the Pi’s version of Linux supports, add this line to root’s crontab:

@reboot sh /root/setup.sh > /root/sound.log 2>&1

Rebooting now works without a monitor and keyboard attached, and the sound processor starts right up. Ready to go!

Leave a comment if you have any questions, this post will be updated as I continue work on the system…

OwnStar – Vulnerability in OnStar Application for GM vehicles

Hack of OnStar Remotelink lets attacker unlock, remote-start, and track cars.

The OwnStar device can detect nearby users of the OnStar RemoteLink application on a mobile phone and can then inject packets into the communication stream to the phone, getting it to give up additional information about the user’s credentials. Those credentials can then be used to gain access to the vehicle’s OnStar account and the full functionality of the OnStar RemoteLink app.

Kamkar says the vulnerability is in the app itself and not the OnStar hardware in GM vehicles. He added that GM and OnStar are working to correct the flaw in the vulnerable mobile application. GM customers who use OnStar can protect themselves for the time being by not using the RemoteLink app.

Good thing I don’t have a GM vehicle that heavily uses OnStar remote services.

Source: ArsTechnica

The Technomancer at Arisia!

This past weekend I packed up and headed to Arisia to work, play, socialize, and, finally put all the costume elements together and become… THE TECHNOMANCER.

The Technomancer!
The Technomancer!

This was the final unveiling of the entire costume the magic staff was created to drive. I’d been adding parts and components for weeks, waiting for others to come in, etc – and in the last week, it all came together.

In summary? It went GREAT. Lots and lots of awesome feedback, oohs and ahs, and tons of geeky conversation around the staff and other parts of the costume. I did learn a lot about what works and what doesn’t work when doing a costume this involved, and while I’m nowhere near done, I’m at a point where I can pick up all the pieces and go to an event, and I’m pretty sure it’ll work well.

Here’s a rundown of everything I added to make the full image work:

  • First, thanks very much to Starlit Creations for making a custom ‘wizards robe’ for my 6’6″ form. She did a great job, exactly to my specs, and it fit me wonderfully.
  • The second big add was a UVEX “Bionic” (yeah, not my name, sorry) faceshield.  I’d been digging around for some sort of ‘mask’ that I could mirror and cover my face, giving that ‘blank look’.  After looking at various environmental filter systems and masks, this shield was exactly right.
  • I added a sheet of ‘one way’ reflective film on the inside of the mask – this turned out to be tremendously difficult as the faceshield needs to flex both horizontally and vertically when being installed, so I couldn’t set the film on the surface while it was on the flat, I had to do it while it was installed, which ended up with some bubbles and wrinkles.  All in all not bad, but I’d like to try to get it perfect.
  • A turtleneck shirt to hide ‘skin’ showing on the neckline, and hide my arms.
  • A pair of black leather driving gloves
  • An extra long belt from my SCA garb
  • My boots from said SCA garb
  • Two lengths of light green lit EL wire and battery packs.  These unfortunately were a disappointment.  Not very bright, and awkward to work with.  I’ll be reworking this part of things.

All assembled, it felt comfortable, looked great, and I was ready to go out in public.

A couple things became apparent really fast…

  • If a person can’t make eye contact with you, they’re nervous and aloof.  They couldn’t see my face – and at least in US culture, the first part of a conversation is making eye contact, which is sort of like “Is it okay to talk to you?” – I guess that’s sort of the point of the ‘faceless’ costume – to make people a little uncomfortable.
  • The mask made it very hard for me to speak loud enough for people to hear me.  Sometimes if I got into a geeky conversation, I’d just flip the mask up – which, naturally, destroys the presentation.  I’m considering a voder-type arrangement moving ahead so I can talk and people will hear me.
  • The mask / hood arrangement can get hot.  Here’s a little secret, I was actually wearing shorts under the robe – so that part was nice and cool (and no one noticed), but I may need to come up with some sort of air circulation solution for the mask.
  • Also, the hood and mask pretty much eliminated my peripheral vision.  Might need to work on that part.
  • The gloves made it hard to feel where the control buttons on the staff were.  That’s definitely up for a change.

I wore the costume and staff for a few hours on Saturday night, and had lots of people taking pictures.  The pic above is from the hotel room before I went out (when I was out in public, the hood was actually pulled forward much more) – but you get the idea.  The EL wire is barely visible 🙁

I have tons and tons and TONS of ideas moving forward, all workable within this costume design (vast improvements on the staff, some small changes to the robes and mask), but for a first time out, I’m pretty psyched!

Arduino Nano “Programmer Not Responding” on a Mac

Arduino Nano v3
Arduino Nano v3

For the Staff project, I’m going to be replacing the existing Arduino Uno R3 with a smaller, more easily embedded Arduino Nano.  The Nano is a heck of a lot smaller than the Uno (makes sense – it’s meant to be permanently installed, while the Uno is a prototyping platform).  I received my Nano a few weeks ago, but immediately ran into a frustrating problem… code would compile, begin to upload, and I’d get the error “stk500_recv(): programmer not responding”

The intarwebz are full of people reporting this problem, unfortunately most are not finding answers.

I went through the usual debugging problems – changing out the USB cable I was using, checking to make sure USB drivers were correct – I could still upload and use code on my Uno, but the Nano flat out refused to accept the new code (and I did check the very common problem of not selecting the correct board in the IDE).

Finally, came across a general discussion about bootloaders, and there was a comment that sometimes these boards do not reset properly.  After some more research, I found some folks using various ‘reset button’ hacks to sort of nudge the board into accepting code.  With a lot of trial an error, I have a procedure that seems to work pretty consistently.  There’s occasional twitches, but with persistence it always loads.

Continue reading “Arduino Nano “Programmer Not Responding” on a Mac”

Video Demo of the Staff

Several people have asked how the project’s coming along, and I realized that the most recent video only showed a little bit of the functionality.  So I dusted off my iMovie skills and whipped up a little demo (complete with background music!  Aren’t you impressed?).  All the current modes are displayed, though the most recent one isn’t quite done yet.

Enjoy!

The Arduino Mini 05 is… well, mini!

Arduino Mini 05
Arduino Mini 05

I’m looking to replace the Arduino Uno in the staff with a smaller controller that will fit in the body of the internal tube. The Mini 05 seemed like the best option… well, received it this weekend, and I have to admit, I’m a little daunted.

On the one hand, it sure will fit in the staff, on the other hand, there’s a lot of very small contact points here. My soldering is pretty crude. I’ll have to put in a header for the USB port first, after that I can probably use a socket, which’ll make connections a lot easier.

Magic Staff – FAQ and Build Details

Idling staff
Idling

Well I’m back home after taking the staff out for Halloween.  I carried around as part of my costume, costume – greeting people coming to the community for trick or treating, but also to hang out with my neighbors.   A lot of people were asking about the staff – both seeing it in action and having heard about me working on it for the last 2-3 months.

Now, I’m back home, the staff is sitting in the corner, still running.  I’m using this as a battery test.  It’s running the ‘sparkle’ pattern, which everyone agrees is the prettiest (see the video from my previous post).  It’s been on, showing patterns and lights now for about 5 hours, easily surpassing what I expected from the 8 C NiMH cells.

People on Hackaday and people I meet in person ask a lot of questions, so I decided to write up an FAQ….

Lets start with the first one…  “Why did you build this?  Where’d you get the idea?”

It all started with a book…

Continue reading “Magic Staff – FAQ and Build Details”

Magic Staff – Takin it out for a spin

Zach and staff
Zach holds the completed staff

The day finally arrived! After a marathon work session on Saturday, I was able to take the staff to a party last night! The batteries held up great, the staff was a great hit, and everyone was asking about it and wanting to see what it did. Talk about inspiring!

There were naturally some ups and downs, with some wins and some losses:

  • WIN: Never. Ever. Underestimate the power of  HOT GLUE.  I solved the ‘solder joints are not strong enough’ problem by embedding the LED strip ends in a few mm of hot glue.  WIN!
  • WIN: By repurposing a shipping container for my son’s new skate wheels, I was able to fashion an enclosure that would hold the Arduino Uno R3 and all the support wiring until my new Arduino Mini 05 arrived.  It gave the staff a ‘navigation light’ look, but the glow of the board lights was sort of nice.
  • WIN: Soldering irons can be used to make holes in plastic.  Shhh, don’t tell anyone.
  • OOPS: I made one major miscalculation.  The battery mounts are custom formed blocks widh hand wound springs for tension.  I put the tension spring on the BOTTOM of the mount, which means the batteries would push down on the spring and disconnect at the slightest bounce.  I’m not looking forward to reworking that section, but this is a learning experience, no?
  • OOPS: I didn’t get a chance to install a power switch, so there’s no ‘off’ state without pulling the cap and disconnecting the power leads.  Oh well.
  • WIN: The batteries lasted much longer than I expected.  The ‘sparkle’ mode draws very little current (the algorithm has one in every 3 LED’s on, and the values it’s using are at 1/4 brightness:
    uint32_t on = strip1.Color(random(64),random(64),random(64));
  • WIN: the coded interrupt routine that uses the button to switch modes works perfectly.  I could change patterns with a quick touch.  I need some more interactive modes, but as a pure display item, total win.
  • WIN? : I totally want to add more features and functions.  A sound sensor so the staff can react to noise / music around it.  A shock sensor (other than the batteries bouncing) so a tap on the floor will cause a ripple function or something.  AN OFF SWITCH.  More interesting patterns.  An external USB port, etc etc.  Many of these things are simple coding updates, but others will require research.

I’ll try and fix the battery tray problem by Halloween, but I think we’re in pretty good shape!

ETA Here’s a video of the staff in action.

Magic Staff – Batteries, load, and runtime

Another few hours of work this weekend saw the Staff cut loose from it’s moorings for the first time.

Staff
Staff running on batteries only for the first time

One of the biggest challenges on this project is power.  The LED strips are 55 tricolor (very bright!) LEDs driven by WS2811 controllers.  The strips are powered at 5v.  Doing some quick load testing on the initial strip (and some online research) showed that each LED has a maximum draw of 60mA, so a 55 LED strip can draw a max of  3.3A @ 5v, and 6 strips can draw something like 20A @ 5v if the entire thing is at full brightness.  That’s a heck of a lot of current.   Compared to that, the Arduino wouldn’t be drawing dink.

I had to balance battery capacity with weight (this thing is meant to be carried in one hand after all).  I considered using D cells, but they’re just too heavy.  I ended up with 8 NiMH C batteries ( http://www.amazon.com/gp/product/B001AX1UQO/ ) from Tenergy.  These are ranked at 5000 mAh @ 1.5v.  I ganged them in groups of 4, connected in parallel.  This gave me 5Ah per group, or 10Ah total.  With a draw of 20A, at full power, it works out to only half an hour of uptime.  Now, there’s a lot of loss in this as well, so realistically, at full power (255,255,255 values on all the LEDs) I expect to get only about 15-20 minutes of use.

In general use, I don’t plan on using this in BLAZING WHITE MODE for more than a few seconds at any given time, but ongoing running will run the batteries down.  The other night I ran the staff using a ‘randomized’ pattern for a good 15 minutes on those batteries without any ill effects, and saw no problems (Check out the video here:  http://youtu.be/LNbIwpk5vdA )