Category: Electronics

All the electronics stuff, microprocessors and more

Made at AMT-June 2019

NOMCOM Fob All The Things dashboard | AMT Software • Bodie/Crafty
Hand Built Speaker | Workshop • David
Recycling Game | Workshop/Laser • Bernard M.
Solid wood credenza | Workshop | Raj J.
Tiny electronic brass jewelry | Electronics | Ray A.
RFID Mint Dispensing Box | Laser+Electronics | Crafty
Wood Signage | CNC Router | James L.
Fabric Kraken stuffed with 720 LEDs | Textiles + Electronics | Crafty
Big empty room

AMT Expansion 2018

This month AMT turns 8 years old and we are growing! We have rented an additional 1200sqft suite in the building. We have a Work Party Weekend planned June 1-3 to upgrade and reconfigure all of AMT. All the key areas at AMT are getting an upgrade :

CoWorking and Classroom are moving in to the new suite. Rad wifi, chill space away from the big machines, and core office amenities are planned for CoWorking. The new Classroom will be reconfigurable and have double the capacity.

Textiles is moving upstairs into the light. The room will now be a clean fabrication hub with Electronics and 3D Printing both expanding into the space made available. Photo printing may or may not stay upstairs — plans are still forming up.

Metal working, bike parking, and new storage including the old lockers will be moving into the old classroom. But before they move in the room is getting a face lift by returning to the cement floors and the walls will get a new coat of paint.

The CNC room and workshop will then be reconfigured to take advantage of the space Metal vacated. We aren’t sure what that is going to look like beyond more workspace and possibly affordable storage for larger short term projects.

Town Hall Meeting May 17th • 7:30PM • Plan the New Space

What expansion means to membership

The other thing that happened in May is after 8 years our rent finally went up. It is still affordable enough that we get to expand. Expansion also means increasing membership volume to cover the new rents and to take advantage of all the upgrades. We are looking to add another 30 members by winter.  Our total capacity before we hit the cap will be 200 members. We feel that offering more classes and the best bargain in co-working will allow us to do this. Please help get the word out!

The New Suite in the Raw

Big empty room

The Vorpal Combat Hexapod

I demonstrated this fun robot at the last BoxBots build night and our general meeting last Thursday. Since then a few folks have asked questions so I thought I would post more detail.

The Vorpal Combat Hexapod is the subject of a Kickstarter campaign I discovered a few weeks ago. I was impressed and decided to back the project. I had a few questions so I contacted the designer, Steve Pendergrast. Then I had a few suggestions and before long we had a rich correspondence. I spent quite a bit more time than I’d expected to, offering thoughts for his wiki, design suggestions, etc.

Steve appreciated my feedback and offered to send me a completed robot if I would promise to demonstrate it for our membership. The robot you see in the photos was made by Steve, not me. Mine will be forthcoming!

You can read the official description on the Kickstarter page and project wiki. Here are my own thoughts and a few of the reasons I like the project so much.

It’s cool!

It has to be to get the kids interested; something that Ray has always understood with BoxBots. While BoxBots offers the thrill of destructive combat, the hexapod offers spidery, insect-ish, crawly coolness with interactive games and programming challenges.

It’s a fun toy

Straight away, this robot offers lot of play value. There are four walk modes, four dance modes, four fight modes, and a built-in record/playback function. To get them interested in the advanced possibilities, you have to get them hooked first. Don’t be intimidated by that array of buttons. At the Boxbots build night, the kids all picked it up very quickly. I couldn’t get the controller out of their hands.

It’s open-source

The circuitry, firmware, and plastic parts are already published. A lot of crowd-funded projects promise release only after funding, and some only publish the STL files, which can be very difficult to edit. Steve has provided the full CAD source (designed in OnShape).

Easy to Accessorize

The Joust and Capture-the-flag games use special accessories that fasten to a standard mount on the robot’s nose. This simplifies add-on design since there’s no need to modify the robot frame. There are also magnets around the perimeter, encouraging fun cosmetic add-ons like eyes and nametags.

Off-the-shelf electronic components

There are no custom circuit boards here. It’s built with two Arduino Nano boards, two Bluetooth boards, a servo controller, buzzer, pot, micro-SD adapter, two pushbutton boards, inexpensive servos, etc. This stuff is all available online if you want to source your own parts. If you’re an Arduino geek, it will all look familiar.

No Soldering!

I think every kid should learn how to use a soldering iron in school, but for some it remains an intimidating barrier. In the hexapod, everything’s connected with push-on jumper wires. (If you source your own parts you will probably have to solder the battery case and switches, since these seldom have matching connectors.)

Scratch programming interface

The controller and robot firmware is written in Arduino’s C-like language, but the robot also supports a beginner-friendly drag-and-drop programming interface built with MIT’s Scratch system. I confess, I haven’t investigated this feature yet, but I’ve been curious about drag-and-drop programming paradigms for years. My first programs were stored on punched cards. Finally, I have an opportunity to see how today’s cool kids learn programming!

It’s 3D printed

The parts print without support, and work fine at low-resolution. You’ll want to get your own spool of filament so you have the color available for replacement parts. Any of our printers will work. I’ve had good luck so far with PLA, but Steve recommends more flexible materials like PETG or ABS.

Anyway, enough gushing. I do not have any financial interest in the project. I just like to encourage a good idea when I see one. The Kickstarter campaign just reached its goal a few days ago, so it’s definitely going to be funded. If you’d like to back the Kickstarter or learn more, here’s the link. You’ll have to act fast; there are only a few days left. (Full disclosure: I do get referral perks if you use this link.) Remember that you always assume some risk with crowd-funding. I’ll make no guarantees, but I’m satisfied that Steve is serious about the project and is no scammer.

Click here for the Hexapod Kickstarter campaign.

If you’d like to see this robot in person, contact me on Slack. I’ll try to arrange a demo.


10W Flashlight for Mom

The original idea was to make a wide angle flashlight that my mother would use when she was out walking the dog. There are a lot of black aluminum tube flashlights out there that are very good but, most of them deal with a narrow beam.  I wanted something that was neither black nor aluminum nor a tube.  I was originally inspired by a youtube video:  How to make a 10W light at 12V from cheap parts Lots of experimenting happened from this starting point and it wasn’t that cheap by the time we got to the end.

Which lens to use and how to mount i t and what portable power system, where all questions that needed multiple attempts to arrive at a solution. In some ways this is an incomplete project, it still needs a better battery charging system than the one I

worked out. The wood case itself was CNC cut on the big router and then I manually rounded over the edges on the router table. I went with smaller finger joints and they came out well.  The cabinet pull for a handle gives it a sense of presense and mass that I try for in most of my designs.  I had hoped to get the flashlight ready for Christmas one year but it was pushed over five months until Mother’s Day the next. She does love it and all reports are that Dad “borrows” it often.


REWARD: Team members for the AMT FATT Project

About the project

Fob All The Things! (FATT) is an AMT project to add fob integration so members can use their accounts to charge laser time, buy vending machine items, use sensitive equipment and get access to the space.

While doors and the laser are currently fob accessible those system are starting to show their age. So we began looking for a solution that was :

  1. maintainable — documentation + language / platform that isn’t too specialized)
  2. repeatable — The results of the project should be able to be repeated down the line should a new thing need to be fobbed.
  3. scalable — simple = doors > complex = vending machine) .
  4. affordable — While it is true that you get what you pay for we need affordable solutions
  5. sustainable — As in modular enough to repair easily and with work arounds/redundancies built in when possible

FATT Products

FATT Products are centered around AMT initiatives that solve problems or allow for access to tools and system for making. This project is under development with a great team of folks but we need more help Here are the current initiative including the New Laser Fob box:

Laser Fob Box

We have a glorious new laser being worked on a few blocks away. 120watts of infrared glory with a more user friendly and safe interface/controller set up. In order to get this project into a ready to use state we need to build a fob box that:

  • Talks to the controller and tracks firing time
  • Allows a use to fob in, validate authorization and track that laser firing time
  • Send various bits of use data back so that it can be used to bill and manage the queue for use

Our current laser as a similar fob box that was developed over time. So we know this can be done.

We have a nice crew of folks on the laser team but we urgently need somebody to take the lead on building the laser fob box if we are going to have a working laser in the space in the next 2-3 weeks.

Vending Machine

The vending machine is a true hackerspace project along the lines of what Nottingham Hackspace, NYC Resistor and ATX Hackerspace. We acquired an old vending machine we are hacking to hold things that facilitate making. The crew of folks working on this has made great progress with the machine hardware and the back end interface but now we need to join the two with FATT “product”.

This project is slightly more complex than the laser fob box but not by much.


The doors were the first fobbed project at AMT way back in the day (6+ years ago). Yeah… and also it is time to replace them as sensor are failing and technology has advanced.

Honor Bar

The honor bar is what you think it is. And assortment of snack products and coffee upstairs. The idea with this project is to be able to fob in, select your products and have it go to your account to be billed once a a month with the other billable things like laser time.


This is what you think it is. This will allow users with ID on file to get beer during meetings and work parties using there fob. We will not be selling beer though.

Wide Format Printer

We got a lovely donation of a wide format printer. It was awesome and now we need to be able to gate-keep it similarly to the laser and charge folks for their consumables.

How to sign up and join the team

Team players should have some or all of the following to offer:

  • Leave a legacy (document)
  • Sees project as product (not prototype)
  • Experience microprocessors (Arduino, Rpi)
  • Solid electronics knowledge including PCBs (custom and off the shelf)
  • Python + Experience working with APIs
  • Can start now and see the project through to at least the Laser Fob Box and the vending machine

Contact [email protected] or chime in on the #fob-all-the-things channel on the AMT Slack team.

The Reward of 25k minuets of laser time

AMT originally got the laser and had it up in running because a dedicated group of volunteers invested their time and money in the laser and were paid back in laser time as well as money. We are following in the footprints of that successful model to offer a reward to those that want to contribute to the next stage at AMT when it comes to not just laser use but automation in general.

The reward of team will be split amongst the core team members for this project.


High Voltage Art

I’d seen the youtube video from the Backyard Scientist guy and wanted to try that project myself.

Asking around for dead microwaves via the AMT mailing list produced more than I needed, but extra is always welcome. I was able to take the microwave apart without killing myself.

I have ideas of doing this in front of people as a science demo so I wanted a setup that was contained, portable and safe. I designed some CAD files to make a setup so that it would hopefully not kill anyone and started cutting the pieces out of plywood on the big CNC machine.

After cutting the parts out on the CNC it was a matter of glue and assembly. The idea is to have an airtight chamber so I could add CO2 at some point to cut down on the fire.

Testing was done on the workbench and lo! I was able to make sparks with the high voltage of the microwave transformer. The trick is to have the two sides with the grain and have the board wet when you are burning it. Took me awhile to figure out that a dry board is not going to happen. Doh!

It creates smoke and you want to do it in a well ventilated area.

See vine of the slow motion horizontal lightning

Brass initials triggering LEDs

This project, brass initials for my buddy’s kids, was executed entirely at Ace Monster Toys. The brass initials hold a little magnet that triggers a reed switch to light a few LEDs. The brass was machined using AMT’s CNC milling machine with CAM G code generated by SolidWorks (and I’m getting up to speed on the free alternative Fusion360). I broke a few 1/8″ end mills before converging on the right settings: 0.1″ depth of cut, 2500 rpm, and a 3 IPM feed. Dry machining with forced air worked well and was compatible with the way I mounted the brass sheet, which was superglued to an aluminum block. I polished the brass with needle files, sandpaper, and a polishing compound as guided by the fantastic Clickspring videos on Youtube, then dipped the pieces in thinned lacquer.

The base is an acrylic disc that I roughed up with large-grit sandpaper to more evenly diffuse the LED light. Next to the reed switch is a little steel block that gives the magnet something to snap on to. The reed switch switches from a couple CR2032 coin batteries charging two 1.8 mF capacitors to dumping their energy into the LEDs through a 100-ohm resistor. The component are messily hot-glued into place (the step I’m least satisfied with), and there’s a thin back piece that screws on with 1-72 brass screws, which let me practice countersinking.

I only put these in the mail yesterday, so the reaction of the recipients is, as yet, unknown.

16 MB .mov file of operation

Adding Five Volts portable power to your project

Thanks to the growth in portable battery options we can hack those “power banks” to make portable, rechargeable five volts power sources for your own projects.

We will be be hacking and comparing two different products that output five volts – a nicely packaged and made external battery pack for older Apple stuff and a new cheapie 18650 powerbank.

a diagram for the ages

Both products are basically the same.  It’s a lithium-ion battery with a USB charger on the front and a boost on the back to output USB standard five volts.  Some differences – the Apple power bank thing has an LED gas gauge to tell you how much charge it has and only starts outputting when you press the button.  It needs that manual button press to start feeding your project the five volts.  The cheapie 18650 powerbank does not need a button press – it’s switch is automatic as soon as you put a load on it, five volts are coming your way.  Also the Apple power bank has some battery protection circuitry in it to stop you from draining the battery to the point it’s damaged internally.  The 18650 powerbank has no such protection and you can kill the battery if you drain it all the way and then some.

pretty packagingLooks mighty pretty in it’s packaging, this was originally designed to be used with Apple products that had their original proprietary 30 pin socket.  Now that Apple has switched to a different proprietary socket everyone had to go out and buy new powerbanks, cables, etc.  Look on ebay for deals on stuff like this where time has moved on.


Let’s voltage outputsopen up the nicer power bank.  Grab a thin blade screwdriver and go to town.  This is an external charger that is rare in that it has a built in USB cable, not a micro socket you plug a cord into. Designed to feed five volts into the original Apple proprietary socket it is out of favor as Apple has switched to a different proprietary socket. Still, five volts is five volts. After prying off the shell with a screwdriver we can see the output side has three different wires.  five volts, ground and some strange Apple proprietary voltage.

We need to cut the old Apple socket offadded wires and solder in our own red and black to the five volts and ground connections.  At that point we have a portable,  rechargeable power supply that outputs five volts a the push of a button.   A little hot glue for strain relief on the USB charging cable and perhaps wrapping it in electrical tape so all the connections are covered.


The cheapie 18650 setup is even easier to hack.  On USB sockets the two outside wires are the power and on this one, it’s five volts and the right and ground on the left.  Knowing that and still putting a bit of color on the socket so we can tell which is which we solder wires onto the exposed connections.

Finally put them all back together again and start charging them up.  We now have two sources of five volts for a project, one with a manual switch and LED gas gauge and the other will give out five volts right away, no switch needed.   If you need five volts for your electronics project at AMT, come talk to me as I have a small supply of both kinds of powerbank available for member projects.


Electronics Tool Rack

Having the right tools when you are puttering around making things is invaluable and having those tools near at hand is a wonderful thing. When revamping the Electronics Area and turning it into a place you are not afraid to work from the pit of darkness and despair it used to be, I noticed we didn’t have the necessary tools needed to do the job. Also we had no place to put said tools even if they where available, so I decided to m
odify the standard tool rack I developed for my workbench at home. It is a standard rack with basically vertical piece of wood between two frames, like an I beam. On each side of that vertical piece you put a collection of PVC tubing to hold whatever you want to hold. The trick is to have an idea of the tools you want to have on it and lay those out before hand, so you know what kind of tubing and how much you need. Some #6 screws, a drill press, bandsaw and CNC up the wood bits and away you go. Rubber feet on the bottom make sure it doesn’t slide away from you as you reach for that next screwdriver. The tools selected for the rack are based on my own experience in doing electronics and detail work. Precision screwdrivers are a must but so is a regular #2 Phillips and flathead. The #2 and #1 Phillips are probably used more than anything. From there it all makes sense to have enough tools but not too many. You can go crazy on the tool rack but it starts to get too large and would take over the tabletop if you let it. Keep it basic and know what you use.