House of Hacks

Wednesday, February 21, 2018

How to design your own DIY sequential turn signals


Description

Are you interested in how to design DIY sequential turn signals? In this episode of House of Hacks, Harley shows a unique design using a couple components to create a tail light sequencer circuit.

There's now a follow-up post with links to block diagrams for this project.

Are you interested in making things around the home and shop? You’ve found the right place. Here at the House of Hacks, we do tutorials, project overviews, tool reviews and more. Generally this involves wood and metal working, electronics, photography and other similar things. If this sounds interesting to you, go subscribe and click the bell to get notifications.

There's a playlist containing videos talking about the House of Hacks' values.

And here’s the most recent video.

For a written transcript, go to How to design your own DIY sequential turn signals

Music under Creative Commons License By Attribution 3.0 by Kevin MacLeod at http://incompetech.com.
Intro/Exit: Hot Swing

Transcript

Interested in sequential turn signal indicators?

Today at the House of Hacks we'll be looking at exactly that.

[Introduction]

Hi! Harley here.

I have a car that has three tail lights on each side and the manufacturer has those coming on all at the same time, for both brakes and turn signal indicators.

And I thought I'd be cool to change that so it would be sequential turn indicators. Kind of like the old Cougars and Mustangs had.

There's a lot of ways you could design a circuit like this.

I believe the old Cougars, and probably the Mustangs too for that matter, had mechanical switches that had a motor driven swiper on them.

And so as that swiper turned, it would have different contacts that would turn the lights on in sequence.

You could also use various timer circuits from RC circuits to 555 timers to anything else that you really wanted to to provide a timing mechanism and then use either transistors or logic circuits to control the sequence turning on.

And of course you could also use micro-controllers like a PIC or an Arduino to accomplish the same task.

When I first started thinking about this project a number of decades ago, a friend of mine, Robert Largent, suggested using an EPROM to store the different patterns in and just use a timer to increment the bottom two address lines and then use higher address lines to switch between Brake, Left, Right indicators.

I built the circuit and it worked great and I've had it sitting around in a box until I get around to rebuilding that car.

I'm a member of a Facebook electronics design group and somebody asked a question, in kind of an ambiguous manner, about LEDs and EPROMs and it reminded me of this project, so I went and dug it out of the box.

This is really just going to be a design overview. I'm not going to go into the details of constructing the circuit or the schematics, but I will talk about it on a block level diagram perspective.

Let's take a closer look at this.

OK. Let's talk about EPROMs for a minute.

There's two types of EPROM. There's serial EPROMs and parallel EPROMs.

The serial ones are designed for serial interfaces, particularly with micro-controllers and things like that and they don't lend themselves to this project.

This project uses parallel EPROMs which are characterized by having multiple address lines coming in and multiple data lines coming out.

Usually you have eight data lines out and any number of address lines going in depending on the size of the EPROM.

Typically we think about an EPROM as you give it an address and you get data out.

Another way of looking at it, which is kind of the same thing, but a little bit different, is you have status inputs and you have status outputs.

It's really kind of the same thing but it's looking at it from a slightly different perspective.

Instead of looking at it through a sequential address space thing like a computer would normally use it, you're looking at it from a input mapping to an output table perspective.

And that's how this project approaches it.

You need an EPROM that has at least five data lines. In this particular case I think it has eight for 256 memory locations.

(I'm not positive on that.)

And you also, for this particular project, need at least six data lines.

I think all of them have a minimum of eight data lines because that's just kind of the typical size of a byte for a computer, so you usually don't have to worry about the data output side, it's more the address input side, depending on the memory size.

The way I have this EPROM setup is there are multiple blocks of four groups.

The four groups correspond to the Off state, the 1 LED state, the 2 LED state and the 3 LED state.

And those four states are just replicated for each of the combinations of Right turn, Left turn and Brake that are possible.

OK, so let's look at the circuit itself.

It's really broken up into a couple different sections.

Power can be 12 volts in a car system normally and the logic circuit needs to run on 5 volts. So we have a little 5 volt regulator here to power the circuit with.

And then we have three input lines. Again, the car is typically 12 volts and it's easiest if we deal with 12 volts on the input side coming from all the switches so we don't have to have 5 volt regulation anywhere else in the car.

So we have red is Right, black is Brake and green is Left turn indicators. All those can be up to 12 volts and then we have a little bit of conditioning circuitry here to drop that to 5 volts.

That's going into the address lines for the EPROM, this large chip being the EPROM. Those are going into the A2, 3 and 4 lines for the EPROM.

Then we have a 555 timer here that is adjustable. It has a little rheostat that I can adjust the timing on.

And it's going into a binary counter. So the binary counter has a clock that's going up and down and it just counts the pulses on that.

So this will convert the clocked pulses into a number that corresponds to 0, 1, 2, 3, 4, it'll actually count up to... I'm not sure how high this particular chip counts, but it counts up to a certain point and then it rolls over and starts back at zero.

Since we're only dealing with two bits to count from zero to three, which gives us our four states for our three lights, we really only care about two of those output lines.

If you put it on output bits 0 and 1 and connect that to address lines 0 and 1, you'll run this clock at the same speed as the 555 timer.

If you change your output bits that you're using on your counter from the bottom two, every time you shift up one output, you're dividing the speed of your counter by two.

So it's easy to get divisions of two on your timer, but then you can also adjust your timer speed, so you have lots of flexibility in terms of how fast this thing cycles through your bottom four bits.

Then we have the bottom six bits of the memory going over to this other board which is basically just designed for high current switching.

It's going into a buffer over here which will eventually be connected to transistors so we're not driving the transistors directly from the EPROM but we're buffering it through a device that can handle that kind of switching more easily.

Then I also have the outputs of this buffer going to these LEDs with some current limiting resistors over here so we can just kind of see the status of that.

Ideally in the future I'll put some transistors along this section that will then control the incandescent lights in the car, if I so choose that way, or I might drive a high-current LED panel to get a little bit more modern look to it.

That's the basic overall system design.

You can see right now I have it setup with the Brake and the Left turn indicator going.

If I disconnect the Brake, now we just have the turn indicator.

If there's nothing going, we have nothing.

We can look at the right turn indicator if I connect that here.

We have just Brakes only, they all come on.

Then if I connect both the turn indicators, we can see the hazard conditions.

Now the interesting thing about this... most cars when you have hazards on and you have brakes, you get one of two conditions. Either it's designed so you get just the hazards and the brake is ignored. Or you get brakes and hazards are ignored. But you don't really have a state indicating both brakes and hazards.

Now with this design, you can actually put anything in those memory spots you want to get any kind of pattern.

In this particular case, I've set it up so that when you have hazards and brakes combined, you actually get all the lights blinking on and off, which is different than hazards or brakes, either one by itself.

So that gives you a little bit more flexibility in this design.

You could also have it setup so that the lights alternate back and forth or any other type of pattern that you want besides just this.

So I happened to choose all blinking like this for that case but you could do anything you want.

But the point being it can be separate from the hazard case and the brake case, which is a little bit different than standard sequential light circuits.

I hope you found this design overview interesting and if you're interested in electronics and photography, wood working, metal working and other shop related projects, I encourage you to subscribe and click the bell notification icon and YouTube will let you know next time I release a video.

Until then, go make something.

Perfection's not required.

Fun is!

Wednesday, February 7, 2018

DIY Valentines card idea 2018 - Magic hearts


Description

Looking for a unique DIY Valentines card idea in 2018? Today you'll see how to make a simple homemade card out of paper craft that will warm a nerd's heart.

Numberphile video that inspired this: https://youtu.be/wKV0GYvR2X8
Last year’s Valentine’s Day video: https://youtu.be/9X152YxYugc

Are you interested in making things around the home and shop? You’ve found the right place. Here at the House of Hacks, we do tutorials, project overviews, tool reviews and more. Generally this involves wood and metal working, electronics, photography and other similar things. If this sounds interesting to you, go subscribe and click the bell to get notifications.

There's a playlist containing videos talking about the House of Hacks' values.

And here’s the most recent video.

For a written transcript, go to DIY Valentines card idea 2018 - Magic hearts

Music under Creative Commons License By Attribution 3.0 by Kevin MacLeod at http://incompetech.com.
Intro/Exit: Hot Swing

Music under Creative Commons License By Attribution 4.0 by Audionautix at http://audionautix.com
Incidental: Alison

YouTube licensed
Incidental: Forget Me Not by E’s Jammy Jams

Transcript

Whether you're a math nerd, or your significant other's a math nerd, or you just enjoy making off-the-wall cool stuff, today at the House of Hacks we're going to make a Valentine's Day card out of a piece of paper and a couple simple materials.

[Intro]

Hi! Harley here.

If you're new here, welcome!

I'm glad you're here and would love to have you subscribe if you're interested in a variety of things related to making things.

Things usually made out of wood, metal, electronics. Today we're going to be doing a little bit of paper crafts because it's Valentine's Day.

I got this idea off a Numberphile video talking about topology. I'll leave a link to the original video down in the description below.

This is real simple to do and easy to make.

All we need is a piece of paper. I chose red because it's Valentine's Day.

A pair of scissors. You could use a knife too I guess if you want.

Something to mark with. I've got a fine tipped Sharpie.

Something to measure with. This is just a blade out of a t-square.

And some tape.

OK. I'm starting here with an 8-1/2 x 11 piece of paper. It can really be any size, but we do need it to be square.

So, the first thing I'm going to do is take my ruler and on the long edge measure out 8-1/2 inches and then cut off the extra.

Now you can use a knife or scissors if you want a nice straight edge. Or if you want something a little decorative, you can just rip it like that.

The next step is to fold it into quarters so we're going to fold it once this way and crease it well.

We're going to be using the crease in a future step so fold it back on itself just to make it easy to see the crease.

And then turn it 90 degrees and fold it again.

And again, fold it back on itself.

And now on each of the points on the creases, we want to measure out 1/2 an inch. It can really be anything you want, but I found 1/2 an inch works well for 8-1/2 by 8-1/2 squares. Larger tends to not work so well.

So just pick tick marks on each one of these at 1/2 inch from the fold.

And now we're going to make squares on each of the corners. So, just draw some lines like so.

They guide you in cutting with the scissors so they just need to be as accurate as you need them to be for cutting.

The next step is we're going to cut out each of the four corners with the scissors.

You could use a knife if you wanted to use a knife on this also.

This is all preparatory steps. So you want to have this done before you actually want to present the card.

I don't know if it's a card or a gift. It kind of could be either one or both, but it's something you need to do kind of in person and talking to them probably.

It's something more of a demonstration.

So you could actually take this to dinner or something like this as long as you take along the materials you need in addition to the paper.

OK. So we're done with the ruler and the marker. This is all the preparation steps are done. We have the little cross looking thing.

We'll need scissors and tape now for the rest of it.

Now at this point you could make up a story.

I'm more of a teacher than a storyteller, so I don't know if I have any good stories to necessarily recommend but you could start something like maybe talking about how you met and your paths crossed or something like that.

I don't know. Maybe sounds a little corny.

But anyway, you want to proceed by making a loop and putting half a twist in one of them. This will make a mobius strip.

Now when you do this, you want to make sure which way you're doing your twist.

So I'm going to be twisting with my right hand overhand and then these get taped together.

So we're kind of making a mobius strip type of thing out of two of these.

And we want to tape the ends together but we also want to tape the backside so it has a little bit more support because we will be cutting this here shortly and it's much more stable if both sides are taped.

Now we want to do the same thing with this one.

Only now instead of... previously we twisted forward, now we need to twist in the reverse direction.

So I'm going to twist this underhand on the right hand side and this gets taped.

And maybe in your storytelling you could talk about how after your paths' crossed at some point you came to embrace life with each other.

Or something like that. Like I said, that sounds a little corny, but I'm not a good storyteller, so don't follow my advice.

So now we have this.

And the next stage is we want to cut along the fold lines. So we're basically cutting each one of these in half lengthwise.

Don't cut through the center piece though where they cross. Just cut the edges first.

And so we take the scissors and just cut along those lines.

The paper ripped a little bit so I'm going to do a quick repair here with a piece of tape on that center piece. The center part ripped where it wasn't supposed to rip.

So, I don't know, maybe you could talk about how you get busy after embracing the relationship and school and work and life circumstances make things crazy and you feel like you're getting torn apart.

And then you go to the other side and cut this edge also along the fold that we started out making.

Everything's cut apart except where we made the cross. Now we want to go ahead and cut the cross apart.

And this is where the actually the magic starts happening. So you want to be winding up your story pretty quickly now because once we snip these last two pieces you can tell them that through everything you've been through your hearts are now entwined together.

OK. That might be a little corny.

But you know, it's Valentine's Day.

So there's the entwined hearts for you to give to your beloved and show her how much you care.

Thanks for joining me on this creative journey that we're on.

And until next time, go make something.

Perfection's not required.

Fun is!

Saturday, February 3, 2018

Movable wall mounted boom arm (redesign)


Description

Need to wall-mount a boom arm? In this episode, Harley looks at a movable wall-mounted boom arm redesign. An overhead adjustable boom arm is a useful piece of photography studio equipment. Previously he showed a design for wall mounting a boom arm that didn't work so well. Today he will present a better design. Overhead boom arms can support many things in a photography studio: hair lights, soft boxes, overhead remote-controlled cameras and many other things. The Impact 7' wall-mounted boom arm has simple holes in it to mount directly to the wall. Harley shows how to mount it to a bracket that can be positioned in many places in the studio.

Horizontal toggle clamps used: http://amzn.to/2GIl2h8 (Affiliate link)
Heavy duty horizontal toggle clamps: http://amzn.to/2EdXX7K (Affiliate link)

Unboxing of the boom arm: https://www.youtube.com/watch?v=_-c8o-rsZ5I&index=1&list=PLWmDBD9Srrwl_aVNC0VjXj3uigC0-FxLo&t=1s
Video of the first design for the mounting bracket: https://www.youtube.com/watch?v=OgWHtRdMG4M&index=2&list=PLWmDBD9Srrwl_aVNC0VjXj3uigC0-FxLo

Are you interested in making things around the home and shop? You’ve found the right place. Here at the House of Hacks, we do tutorials, project overviews, tool reviews and more. Generally this involves wood and metal working, electronics, photography and other similar things. If this sounds interesting to you, go subscribe and click the bell to get notifications.

Multiplying binary numbers
Bits of Binary playlist

There's a playlist containing videos talking about the House of Hacks' values.

And here’s the most recent video.

For a written transcript, go to Movable wall mounted boom arm (redesign)

Music under Creative Commons License By Attribution 3.0 by Kevin MacLeod at http://incompetech.com.
Intro/Exit: Hot Swing
Incidental:
  • Clipper
  • Cool Blast
  • Iron Bacon
  • What You Want ver 2


Transcript

Today we're going to look at the failure of this moveable wall mounted boom arm bracket and look at the failure reasons and come up with a new design. Hopefully, one that works.

[Introduction]

Hi! Harley here.

If you're new and are interested in making things out of wood, metal, electronics and other similar types of materials, hit the subscribe button and then hit the bell notification and YouTube will let you know next time there's something released here at the House of Hacks.

You know, sometimes you have a great idea, but the execution of it just doesn't work quite right.

Well, that's what happened last summer. I made a video up here about making a moveable wall-mounted bracket for this Impact 7' boom arm that's used in a photography studio.

And the idea was we'd have a piece of metal that's mounted to the wall and this bracket could be mounted anywhere along that metal to provide adjustability for where the long arm boom arm is mounted.

The idea was there'd be a couple pins here that drop in to holes in the metal and there's a cam activated lock here that keeps it from shifting around while it's being used.

There were a couple problems with this design.

First, of all, the pins that were epoxied in place in here didn't have enough depth to them, into the wood, and so they fell out fairly easily.

The second problem is this cam lock is asymmetrical in the way that it was providing support.

The boom arm can swing to give you adjustability on your position of whatever you have mounted to it. And if you swung one way, this worked fine. But if you swung it the other way, the whole mounting bracket would have a tendency to tilt because it didn't have support on both sides.

So, in this redesign, I'm going to address both these issues.

OK. The new game plan is to replace the pins that fell out with some bolts that will go through the wood all the way. The bolts are longer than this wood and so the bottom of the bolt will drop into the holes in the perforated tubing that's going to be on the wall to hold it in place.

To hold the bolt in the wood, I've got some T-nuts that will just go in like so, so it'll be flush on the bottom where it mounts against the wood, or against the metal and it'll just be held in like so.

To lock it in place, I've got some toggle clamps. These are inexpensive. I picked them up on Amazon, a four pack for less than $9. I was really surprised that I could get some this inexpensively. And I'll leave a link to it down in the description in case you're interested in something like this.

They're rated at 100 pounds each. I'll have two, one on each side. So that should be able to hold it in without any problem. I'll cut a couple pieces of wood, this size, to mount on each side here to mount this to and I'll set the spacing such that when they're open, there's enough room to drop it into place and when it's closed, it will lock up tight against the metal on the wall.

So, let's start putting this all together.

[Project work]

OK. After I got the bolts in and tried test fitting it in the holes, the clearances were just such that there was a little bit more interference than I would have liked. And so I took the bolts off and put them on the lathe and just filed off the ends of the bolts.

(You can probably see it a little bit better with the contrast.)

So the part of the bolt that sticks out of the T-nut is filed off but the threads that thread into the T-nut are still there. So it will still go in just fine this way and, as this gets bottomed out and tightened up, we can see there's just enough extra room for those to fit in there just fine.

So now I'll go put this back on the mounting bracket and figure out where the toggle clamps go.

[Project work]

So, I mounted the clamp on the wood such that the fixed part of the clamp is fairly flush with the end of the wood. There's some adjustability in here so I wasn't looking for exact precision, just kind of got in the ballpark.

And the bolts that are coming out of the T-nuts, extending beyond, is less than the total throw of this bolt on the latch. So, the difference between the closed position and the opened position is a certain measurement. And that measurement is greater than the length of the bolts that are extending out the bottom of the T-nuts. So, in theory, I should be able to set one of these clamps in the locked position and put it right up here against the perforated pipe and mark the block's position here on the mounting bracket. And when this is mounted in, when it's closed, it should be locked and when it unlocks there should be enough movement to be able to pull the bracket up off the perforated pipes. That's the theory. We'll put it together and hopefully everything works out.

[Project work]

OK. I'm much more pleased with the way this works. It's much more sturdy. It seems much more secure. I think it's going to work much better.

As you may have noticed, I was making some adjustments to this. The way this works is there's a barrel that moves in and out in this bushing and in the end of the barrel, there's a screw that has a rubber tip on it and a lock nut, so you can adjust the length of the screw that's coming out of it with the rubber bumper on it and then you can lock it in place with the lock nut. And that's what I was doing with the pliers, was just kind of getting that tightened down and adjusting that. So now when you lock it in place, there's just a little bit of resistance before it locks in and so it holds it pretty secure. And I did that on both sides.

Like I said, these are rated on the web site at, I think, 99 pounds of force that they should take. So, both of them combined is 200 pounds and that should be plenty sufficient, I think, even with the leverage that this will have when you put a light on it.

But we won't know until we really get it in place in the studio. So, let's head over to the studio and see how it works in real life.

[Driving]

OK. That looks like it's going to work pretty well. It's a whole lot more sturdy than it was before particularly when it's out on the outer edges which is really where we had the problem last time. Like I said last time, it would have a tendency to torque this base sideways when it was out at the far angles and not having any problems like that now. It's really, really good and solid.

So, I think this is going to work. We'll now put it in practice here in the studio and let people use it and see how it works in the real world. Hopefully this will be the last time I have to address this issue.

Thanks for joining me on this creative journey that we're all on.

Until next time, go make something.

Perfection's not required.

Fun is!