posts tagged with the keyword ‘electronics’

2018.08.19

pcbway-attiny85-pcb-01

The crew at PCBWay got in touch with me to see if I’d like to try out their service. I’ve used other PCB manufacturers in the past, so I figured I’d give PCBWay a try to see how they worked. The ordering process was not the smoothest, but the boards turned out well, were very affordable, and they got to me pretty quickly.

pcbway-attiny85-pcb-03

I designed this PCB years ago and I’ve used them a lot in my noisemakers and while I might modify them in the future, they are still pretty useful, so I figured I’d make more.

pcbway-001

I had my Gerber files ZIP’d up and ready for upload, so I started the process with PCBWay, which I assumed would be similar to other PCB manufacturers I’ve used. Yup, pretty close. Note that for color you can choose green, red, yellow, blue, white, black, or “none” at the same cost, but choosing purple, matte green or matte black cost bit more. (Not quite double, but more than just a few bucks.) I’m not sure what “none” looks like, but I am curious.

pcbway-003

So I added the boards to my cart, and I first noticed that I could not change the quantity. This was a little annoying, as I wanted to try different quantities to see how it affected the price. You can do that, but only at the first step in the process, at the “Online Quote” step, not once it’s in your cart, so make sure you know how many you want before your add them to your cart!

When I went to checkout I then found out I could not check out. Right, seems my boards were “Subject to audit.” Yes, they had to be approved by someone (a human I guess) before I could order them, which seemed weird. (Notice the yellow highlighting I added to the cart image above.)

pcbway-002

Now, this is partially my fault, as I didn’t see this the first time I uploaded files. There is a little bit of text on the upload form that shows it could take “10min to 1 hours” for approval. I’m not sure exactly how long it took, as I did this late one night and didn’t get an email about approval until the next day. This was the most annoying part of the ordering process. When I want to order something I don’t want to have to wait hours, or even one hour between putting it in my cart and being able to order it. Perhaps they could make it so that you can place your order, and then if not approved for some reason (?) they could refund the order. Or who knows, maybe this whole “approval” thing is due to some new tariff laws. I have no idea.

pcbway-006

Like I said, pricing is good. I got 75 boards for $32. That’s about 43 cents per PCB. These are tiny boards though, so obviously the price per board goes up when you get larger boards. With approval completed (by some human, I guess) I was able to move on to shipping options.

pcbway-007

I went with shipping via DHL, which came in at $21, so the order total for 75 boards ended up being $53, making each board cost approximately 71 cents. (Obviously ordering more would probably bring that price down, but I really doubt I need more than 75 of these right now.)

I uploaded the PCB files on July 21st, and they were approved and ordered by July 22nd. Manufacturing was completed by July 25th and they were then shipped via DHL July 27th and I got them by July 30th. That’s about an 8 day turnaround for these printed circuit boards. (With some weekend days in there.) Not bad! For US shipping DHL is probably the best option for getting them fast. There were two cheap shipping options, one being an ePacket (which seems to be how I get most of my eBay electronics delivered) which was $8 but had a 10 to 15 day delivery time frame. There was also “China Post” option which was $7 but showed 25 to 40 days for delivery. Wow. So the ePacket is not too bad if you do not need your boards in a hurry.

pcbway-attiny85-pcb-02

The boards from PCBWay look good and got to me fast. They were also very affordable. Overall it was a good experience except for the issue of having to wait until files are approved before ordering and not being able to change quantities once the item is in your cart.

2018.06.12

buzz-buzz-2191

BuzzBuzz is a device that makes noise and light using electricity (somewhere around 40,000 volts, approximately.) There are five “high voltage generators” connected to buttons that when pressed cause them to create a spark with a loud “ZAP!” and then continue to make noise (and light) while the button is held down.

buzz-buzz-2192

BuzzBuzz was heavily inspired by something Mario the Maker created. I had one of the high-voltage generators for a while and was planning to do something with it. I had an idea for a project and had started on it, but once I saw this thing I altered my plans.

buzz-buzz-2196

The size of BuzzBuzz was somewhat dictated by the size of materials I had on hand, or could easily get at no cost. The top piece of clear acrylic is from a bulk buy at Midland Plastics where many of the members of Milwaukee Makerspace shop for scrap pieces. Since I had that piece of clear acrylic, it pretty much determined the size of the top of the enclosure.

buzz-buzz-2200

For the walls of the enclosure I grabbed some 16mm thick plywood from the scrap bins at Milwaukee Makerspace. There’s a local tool & die company that donates these pieces to us. They are long and skinny and always have these weird laser cut marking on them, because they use them for calibrating their lasers. I wanted to see if I could cut through the 16mm plywood with the 130 watt laser cutter I have access to. Indeed, it could! At 4mm per second, which is probably the slowest we should cut at. The cuts were not the greatest, but it was more a matter of “Hmmm, will this even work!?” than anything else.

buzz-buzz-2201

You’ll also notice the hexagonal holes on the sides. Those are “sound holes” since my first assembly demonstrated that the box fully closed up was too quiet, so I decided to add holes that the sound could spill out of. It also adds a nice look, and if you associate the “Buzz” in the name with bees, and notice the holes are hexagonal, well, it all fits.

I mounted the AA batteries on the outside so that you can easily see the power source (it’s interesting that 40,000 volts AC can be produced by just 4.5 volts DC) and so that I can easily change batteries without opening the thing. There are two battery packs because one tended to drain too quickly. I may add an AC adapter in the future so that I can convert AC to DC to AC.

(One more fun fact: The battery holders were one of the most problematic parts of this project. I wasted more time trying to get these cheap battery holders to work. The spacing and springs kept making it so the batteries did not make good contact. I started with a 5-pack of battery holders and trashed two of them just trying to modify them to work. Luckily I got two of them working well enough.)

part-3d

I designed and 3D printed the parts that hold down the high-voltage generators and also allow for bolts to be inserted to carry the electricity. (The design of these parts was inspired by the structures that hold overhead power lines.) The bolts can be screwed in or out to adjust the gap, which gives different results for the zap. I started with the narrowest gap and then did the widest gap, and then calculated the three distances in-between. (For the widest gap, you don’t want to go too wide, because if it can’t properly spark, it’ll burn out the unit.)

part-top-view-3d

As you may know, I design 3D objects with OpenSCAD. Once I had my object completed, I did a projection to get what it would look like from a top view. This is the 3D version of that.

part-top-view-2d

I then render it into a 2D version I can export as an SVG file. This allowed me to easily do the layout needed for the laser cut parts.

full-layout-2d

Here’s a top view. The reddish parts will be cut from the top clear acrylic panel and hold the buttons as well as an old SparkFun key switch I had in my parts bin. The grey pieces are for the bottom part of the enclosure which hold the high-voltage generators and the mounts. I ended up printing a full-scale paper version and using it as a template to mark the holes that needed to be drilled. It did not have to be prefect, so close enough was fine.

buzz-buzz-2210

For the construction, there are some screws on the bottom to hold the bottom pieces to the two side pieces, and then the front and rear panels can slide into place and get held in by just one screw on each side. This is not the most elegant, but I realized somewhere along the build process that I did not have a good way to complete assembly or take it apart. This is what I came up with, and it worked well.

buzz-buzz-2205

I used two contrasting stains, for a light and dark look, which I think matched the burned laser cut edges, and allowed for making the inside of the enclosure dark so the zappers could light up the inside.

buzz-buzz-2206

If you’re wondering why there are two rows of buttons, I really liked the symmetry, but I also wanted something I could use when displaying at a table, so that if you’re behind the table talking to someone, you can demo it and press the buttons on your side, and they can try it with the buttons on their side. (In the museum exhibits business we try to make things that are not single used components, so that more than one person can engage with a thing at a time.)

buzz-buzz-2227

While this was a bit of a rush to get done by Bay View Gallery Night, and like most projects, there are things I maybe would have done differently (or at least in a different order) I’m really pleased with how it turned out. I also brought it to Milwaukee Makerspace to show off and got a lot of positive feedback.

Here’s a video showing operation of the BuzzBuzz. It was difficult to capture on file (well, solid state memory) exactly what it looks like, so this is an approximation. You’ll probably want to see it in person to appreciate the full power of this battlestation device.

buzz-buzz-2189

buzz-buzz-2208

2018.02.03

big-switch-little-light-0523

This project started like many of my projects… Someone says something, and I have a reaction to it. I might say something, or I might not say anything, but I’ll get an idea, and decide to do something. Sometimes it’s a ridiculous idea, and that doesn’t really matter. In fact, ridiculous ideas are probably more likely to be explored.

big-switch-little-light-0546

This one started when a local teacher got in touch with Milwaukee Makerspace about donating a bunch of industrial control equipment. Luckily Tom and a few other members were interested enough to go look through nine boxes and transport them back to the space so members could look through them. I should note this is a common thing. When people want to get rid of things we look for a “Champion”. Basically someone who will take responsibility for the stuff. If they bring it to the space we ask that whatever members don’t take “goes away” within a week or so. (Typically this means the dumpster, but not always. At a minimum, some members take some things and divert them from the landfill. Sometimes things are donated to others or recycled.)

big-switch-little-light-0562

This load was a bunch of industrial electronics. Not super useful for most of our members, but many did find some good things. I found some neat switches, and in particular this large switch with a nick “CLUNK!” sound that said it was capable of handling 690 volts…

big-switch-little-light-0540

Steve and I were looking at it as I clicked it on and off and I mentioned how many volts it could handle and he said “Hey, you need to make it turn on an LED!” which was (probably) a joke, since an LED requires roughly 3 volts, which is quite a bit less than 690 volts. (In fact, it’s approximately 687 volts less!)

big-switch-little-light-0548

So I did what I had to do… I had to assemble the switch into a device that could turn on (and off) and LED. I had also found (and destroyed) an old data tape, but I managed to save the nice Aluminum plate that served as the base of the data tape. (Seriously, some of those old tapes were sort of beautiful!) Since I now had to weird objects, I just combined them with some wire, an LED, and LED panel mount, a battery holder, and two AA batteries. The rest is… history!?

big-switch-little-light-0544

There’s also a Sintra plate on the bottom that the battery holder screws into to hold it in place. And some tape, and some hot glue. (It’s not a project until you add the hot glue!)

big-switch-little-light-056A

So yeah, it’s a but ridiculous, but it’s also somewhat interesting. In some of my projects I don’t even add a switch. This actually seems very common in “maker” projects. Why add a switch when you can just apply and cut power by plugging a thing in!? So why not make the switch the BIG THING in the project. Many times larger than the batteries and the thing you’re actually turning on. Hell, it’s almost art!

Because the switch sounds so amazing, I had to make a video. Oh, also you can see the LED turn on, so there’s no trickery in this video.

Also, worse case, if I keep this thing around I’ll have a nice big high voltage rated switch I can cannibalize for another project. So that’s a big win in my book.

(Oh, sorry about the terrible photos of the blue LED. I need to do better next time.)

2017.09.27

Moxie

A large part of the Power Racing Series is Moxie. Moxie is best described as, being awesome. The crowd gets to vote for your car using the Moxie Board. Each button press equals a vote. Being fast is one way to get points, but another way is by being awesome… so, Moxie.

Above you’ll see a photo of the official Moxie Board used by the series. Since we also had a PPPRS race during Maker Faire Milwaukee, which overlapped the race in New York, we had to build our own Moxie Board, so here’s what we did…

The Moxie Board

It looks fairly similar, but it’s a bit smaller and lighter than the original, and it’s got 24 buttons instead of 30 (though I believe the original was recently expanded to have that 30 buttons. Who knew there’d ever be that many cars in a race!)

I got some Coroplast from Midland Plastics for super cheap, and they didn’t have any wide enough, so the black strip running down the center is gaff tape used to hold two pieces together to be wide enough. I then found some scrap wood in the shop at work which was long enough, but too skinny to be used for anything else, and built a simple frame with some small blocks of HDPE in the corners to hold it all together. (I was told the reduced weight of this Moxie Board was a big plus.)

The front is screwed into the wood frame, and the back is held in place with some VELCRO┬« hook and loop so we could open it to get to the electronics…

As for the inside and the electronics, while the original uses an Arduino Mega with a Bluetooth module to send real-time updates to Patrick’s Android phone which is running some special app, I chose to do it differently.

moxie-board-04

I’m using a Teensy 3.5 which has plenty of input pins and a built-in MicroSD card slot. The way it works is simple, each button represents a number from 1 to 24, and when pressed, the Teensy gets the value of every button, with the ones not being pressed equal to 0 and the one being pressed equal to 1, and then writes it to a file called MOXIE.csv. When the race is over you just put the MicroSD card in a card reader and import the CSV file into a spreadsheet and grab the last row. (Hopefully your spreadsheet is set up with the names of the cars in the corresponding columns.)

In testing, this all worked fine, but obviously the real world had to come along and crush my hopes and dreams…

moxie-board-05

Failure #1: Because the Teensy is a low power device, it doesn’t draw much power from the USB battery pack we were using. I’ve seen this before, so I use a battery pack with a built-in LED “flashlight” that stays on, as long as you press and hold the button when turning it on. I told this to two people, but forgot to write instructions to put inside the Moxie Board, so there’s a chance this was not done properly and power was lost. (There is an indicator LED that lights up when a button is pressed, but not a “POWER ON” LED which would have helped… maybe.

Maybe Failure #2: It could be that my code isn’t quite right. I do not have the most recent code that the official Moxie Board is running, but I have an older version that may be close. My code is a little different, but should yield the same results… I think. This is worth checking on.

I also do not have a good way to attach Moxie Labels, so they are just attached with tape or Hook and Loop for now. Ran out of time for anything better. :/

One more note! In the photo there’s a bunch of green wire and LEDs attached to the front of the Moxie Board. Those were added for the night race. All the actual wiring for the Moxie Board is located on the inside.

moxie-board-03

I’ve heard of one other group working on a Moxie Board that will use a Raspberry Pi, which I thought about doing as well, but ended up choosing a Teensy instead. As we add more races, we’re going to need more boards, so I’m hoping we see more ideas and eventually come up with even better ideas. (Note that I wanted to stay simple because simple gets done while over-complex builds, while fun, don’t always get finished, or work properly. But then, who am I to talk!?)

2017.05.29

PCB

Hey, it’s only been six months since my last post about motor controllers and the Power Racing Series so I guess it’s time for an update! If you missed it, I’m working on a tiny electric vehicle that can serve as a reference for teams of beginners to build their own.

Controller

In the last post I talked about a cheap motor controller that required an expensive throttle and alluded to a method of using a cheaper throttle… here is that method.

I started by asking questions on the Power Racing Series Google Group, and people much smarter than myself offered advice, and that’s where I learned about digital potentiometers. I ended up testing my idea with help from this tutorial and eventually got an MCP4131-104E/P-ND digital potentiometer (for less than $1.00) and paired it with an Arduino Nano that was less than $2.50 to create a converter that allows a cheap throttle to be used with a cheap controller.

If at any point you feel like saying “Hey dummy! You should have done it this way!” feel free to leave a comment. Most of my crazy pursuits involve me learning a lot along the way, and this is no exception, so I’ll keep going.

Controller

After I had a working prototype on a protoboard I decided to design a PCB because I’ve been working on getting better at PCB design for the last two years now, and it’s sort of fun (and challenging!) This is the most complex board I’ve worked on so far, and of course, mistake were made…

First of all, see those wires coming off the board? There should be screw terminals there, but I was unaware that the holes were the wrong size and the pins of the screw terminals did not fit. Argh… wires will do for now.

Controller

Everything wired up and ready to go! Except, it didn’t go… Seems I managed to not quite route everything the right way. Back to the drawing, and tracing all the connections with a meter, and I discovered a connection that shouldn’t be there…

Controller

…but that’s what Dremels are for! I was able to cut the trace and get it working. Back to the computer to make a few changes to the PCB. (And yes, I am still using Fritzing. I’ve gotten used to it, and know how it works, so… okay then.)

Controller

A few weeks later I got a new version from our friends at OSH Park and this one fixed the issues and worked! I should still get similar screw terminals but hey, it does what it should do, so that’s something.

You might notice some of the analog pins and some ground connections broken out at the front edge of the board. There are for future enhancements. It would be fairly easy to add in “cruise control” (for parades) or a speed limiter, perhaps with a keyed switch, to allow kids to drive the vehicle safely. (Again, people smarter than me.)

Controller

Whomp! Here’s my “breadboard” showing everything. Batteries to power the motor, and a buck converter to drop the voltage to 12v for the Arduino and a cooling fan. The throttle connected to the converter and then to the motor controller to control things. We’ve also got a DPDT (double-pole, double-throw) switch in there to allow for forward and reverse to the vehicle, and a kill switch, fuse, and voltage meter. Basically all this will need to be jammed into the vehicle to control it. (Don’t worry, we’ll be using larger batteries, thicker wire, and a larger motor.)

Controller

Here’s the controller with a cooling fan mounted to it. I’ll provide files to laser cut or 3D print the mounting pieces, or templates to cut by hand, which is totally doable. (I learned the hard way last year that if not properly cooled the capacitors on these controllers can blow.)

Controller

I also added a bright blue LED to the board (you can choose another color) to indicate when it’s receiving power. Another suggestion I got from someone. I’m sure there is still room for improvement (like, you know, diodes) but hey, it works and I look forward to testing it.

« Older Entries |


buy the button:

Buy The Button