How to make a binary clock: design

Description

Want to make an Arduino project a bit more complicated than blink? In today's episode of House of Hacks, Harley starts a project on how to make a binary clock. This project will use an Arduino and be presented in multiple parts. Today, the first part will be the overall requirements and design. In future videos, the software, circuit and finishing it off with an enclosure will be covered.

Resources

• All the information to make this project: https://www.house-of-hacks.com/p/arduino-project-binary-clock.html
• If you just want to buy one: https://amzn.to/3eGXFVD (Amazon affiliate link)
• Get a digital version of the new Arduino poster by signing up for the House of Hacks newsletter: https://list-optin.house-of-hacks.com/arduino
• Or a printed copy of the poster can be bought on the House of Hacks store: http://store.house-of-hacks.com

Contents

• 0:00 Project introduction
• 0:59 Welcome and about House of Hacks
• 1:19 Description of BCD
• 2:14 BCD for binary clocks
• 3:05 Project requirements
• 4:02 Controlling the LEDs
• 5:45 Tracking the time
• 6:18 Adjusting the time
• 7:23 Arduino selection

About

Here at House of Hacks we do tutorials, project overviews, tool reviews and more related to making things around the home and shop. Generally this involves wood and metal working, electronics, photography and other similar things. If this sounds interesting to you, you may subscribe here.

If you’re interested in learning more about the House of Hacks' values, here’s a playlist for you.

And here’s the most recent video.

For a written transcript, go to How to make a binary clock

Here's a list of the tools I use.

Music under Creative Commons License By Attribution 4.0 by Kevin MacLeod at http://incompetech.com.
Intro/Exit: "Hot Swing"

Transcript

A number of years ago, at a software conference, one of the evening activities as an outing to a hands-on science museum.

While there, I noticed and picked up this binary clock.

It uses something called BCD encoding and I thought it'd be kind of cool to make my own version of this as a project.

Technically, it could be done with some simple logic circuits and a timer.

But this would involve more hardware design and wiring than I wanted to be involved with and so I'm going to go the easy route and use an Arduino.

This is going to be done in four parts.

Part one today is the basic requirements and design.

Than as I'm waiting for parts to come in, I'll go over the software design and how to actually do some testing without having a complete circuit finished.

The third video I'll assemble all the circuits and get it running.

And then the fourth video will be creating an enclosure for it.

Welcome to the House of Hacks. If we’re just meeting, I’m Harley and I make stuff out a variety of materials.

For example, in this project, we're doing design discussions, and software and electronics and mixed media for the enclosure.

If making a things out of a variety of materials in the workshop is something that's your thing, consider subscribing and you won’t miss future episodes.

BCD is an acronym for Binary Coded Decimal and this was an encoding system that IBM came up with nearly a 100 years ago in the 1920s for use in their early mechanical devices.

As early computers came on the scene, they took this basic coding that they used and expanded upon it to use in the computers.

It was called EBCDIC at the time and was actually used until relatively recently.

Interestingly, early in my career, I had to write an ASCII to EBCDIC conversion routine for use by our business partners.

Before going to the whiteboard, a couple notes.

First, the code and schematics for this project, is available for free download off of GitHub.

And second, a commercial version of this clock, kind of like the one that I picked up at the conference, as well as all the materials I'm using in the project are available on Amazon. I’ll leave links for everything down in the description below.

In BCD, each column represents a decimal digit, coded in binary. The first column is the tens digit for the hours, the second is the units column for the hours. Next, we have the tens and units digits for the minutes and the tens and units digits for the seconds.

In decimal, we need four bits to cover the all digits 0-9 in binary. So all the units columns on the LEDs have four LEDs. Because on a clock, none of the tens digits go all the way to 9, we don’t need a full 4 bits for each of the tens columns. Hours for example only go to 2, so we only need 2 bits for a 24 hour clock. The minutes and seconds only go to five so we only need three bits for those.

So, to make this, what are our requirements?

For the LEDs, we have 3 groups of 4 and 2 groups of 3 for a total of 18 and another 2 for a total of 20 LEDs that we need to control.

Second, we need a way of keeping track of the time.

Third, we need a way to set the time.

I’ll talk about all these requirements in detail but first I’m excited to announce that I’m working on some Arduino training materials. I have an Arduino reference poster available now and am working on a book for people new to digital electronics and programming the Arduino. A digital version of the poster is available by just signing up to the House of Hacks mailing list where I’ll keep you updated on things happening here. I won’t bombard your email with a bunch of stuff. Just occasional updates when products are released and an occasional news item that I think you might find interesting related to making things. If you’re interested in this, there’s a link below in the description below.

Now, back to the design...

Looking at controlling the LEDs, my first inclination was to think about this as a single string of 20 bits where each digit in each group was put inline with the rest of the bits. The common way of working with large numbers of LEDs is to use a '595 based shift register. This only requires three pins on the Arduino but provides a number of digital outputs. This is so commonly used that there’s a shiftOut command built into the Arduino ecosystem. ‘595 chips typically only work with 8 bits (although there are variants that have more bits) but they can be daisy chained together so you can have an almost arbitrary number of digital outputs, all controlled by only three pins.

Since there’s 20 bits needed and each ‘595 provides 8 bits, I thought about using three shift registers, daisy chained together. This would give 8 times 3, or 24, bits. The first 20 bits would be used and the last 4 bits would be ignored.

I coded up a prototype sketch using this idea but it ended up being more messy than I really liked. All the code was one big blob with a bunch of dependencies spread throughout the whole thing. Some of that mess could be cleaned up with some refactoring, but it was still going to be more messy than I really liked.

Upon reflection, I realized each group of two numbers only needs at most 7 bits and I have three groups. For the purposes of this project, I could still use the three ‘595s but instead of daisy chaining them together, I could connect each one to the Arduino directly. This would help make the code cleaner. Each ‘595 needs three pins, so that’d be a total of 9 pins for the LEDs instead of 3. Let’s look at the rest of the requirements and see if there are enough pins.

To track time, the most reliable would be to use a clock module. A real time clock module, also called an RTC, is designed to interface with micro controllers and has it’s own battery backup. There are a number of different models. I selected to use a DS1307 because they can be had inexpensively and communicate with the Arduino using only three pins over the I2C bus.

It would also be possible to use the Arduino itself to track the time although I’m not to sure how accurate that would be. It would provide a software only solution though.

Finally, we need a way to set the time.

The commercial unit I have uses two buttons. One increases the hour each time it’s pressed. The other increases the minute each time it’s pressed and if they’re both pressed at the same time, the seconds are increased.

This could work, but I don’t have any good buttons that’d be appropriate for mounting in an enclosure and, in my spare parts bin, I have a rotary encoder.

Rotary encoders come in different styles. This particular one allows the user to spin it in either direction without any limits. It can also be pressed to indicate an event. The micro controller can detect which direction it’s turned and take appropriate action.

I think this would be easier to make accessible to the user in the enclosure, so I’m going to use it. It uses two pins to the Arduino to communicate the rotary action and one pin to communicate being pressed.

So, all in all, I’m looking at using 9 pins for the three ‘595s, 2 pins for the clock module and 3 pins for the rotary encoder. A total of 14 pins.

Since I want to keep this pretty compact, I’m going to select the Arduino Micro. It’s only about 2 inches long and about 3/4 inch wide and designed to go in breadboards and pre-made circuit boards with standard hole spacing. And it has 18 digital I/O pins. Four more than then 14 that we need.

I think it should work well.

So, I’ll go order the parts and, while waiting for them, I'll show you the software in this video.

If that video hasn’t been released yet, I’ll see you in this other video where I do an Arduino project simulating wind to make wind chimes sound indoors.

After watching that, go make something.

Perfection isn't required. Fun is!

Universal Mobile Base For Table Saw and other tools - Portamate PM-1100

Description

Imagine, what would shop life be like if you could easily move any tool around? In this episode of the House of Hacks, Harley opens, assembles and installs a universal mobile base for table saw. Used in this video is a Bora Portamate PM-1100 kit that is a DIY mobile base for power tools.

Portamate PM-1100 (Amazon affiliate link)

Here at House of Hacks we do tutorials, project overviews, tool reviews and more related to making things around the home and shop. Generally this involves wood and metal working, electronics, photography and other similar things. If this sounds interesting to you, you may subscribe here.

If you’re interested in learning more about the House of Hacks' values, here’s a playlist for you.

And here’s the most recent video.

For a written transcript, go to Universal Mobile Base For Table Saw and other tools - Portamate PM-1100

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

Transcript

Imagine, what would it be like if you could move your larger tools around the workshop?

How would a universal mobile base for your table saw or other tools change your workflow?

Would you have more flexibility for storage?

Would your shop be more space efficient?

Would your tools be easier to use for different sizes of materials?

Today at the House of Hacks we’re going to be looking at how to do this.

About 18 months ago, I went to my Dad’s to pick up some tools that had been my Granddad's. When I got back, I did a video of what I brought back with me and I'll leave a link up here in the cards.

Recently, I made another trip to pick up a few more things that had been left behind. Most notably was a larger table saw that had been my Granddad's and he'd built a base for it.

It's going to be a great upgrade to my current small one but it's much larger and won't fit in the workshop the way it's currently organized.

So I looked at what I needed and what I had and changed my approach to my shop's organization.

Previously, all my large tools were set and ready to use in fixed locations. This had the advantage of being quick to setup.

But it has two disadvantages. One is it takes more floor space because you have to dedicate room around the tool in order to work.

And two, you have less flexibility in your material handling in and out of the equipment.

In addition to the tools taking up floor space, I also had two 6' snap together utility shelves that contained various supplies and small bench tools.

I decided to change to a mobile layout where most of the large tools are on movable bases.

This will allow them to be stored closer together for more compact and efficient use of floor space and it'll give more flexibility for material handling.

This more efficient use of floor space will allow me to get the larger table saw in the workshop.

It does come at a cost though of more setup time.

To accomplish this, I did two things.

First, I split the two 6' shelf units into four 3' shelf units and then hung them from the ceiling.

This allows better space utilization closer to the ceiling and it frees up a lot of floor space.

Second, I converted a number of tools with fixed bases to have mobile bases.

This conversion is the topic of today's video.

But first, welcome to the House of Hacks.

If we're just meeting, I'm Harley and I make stuff out of wood, metal and sometimes other materials. And sometimes I talk about other workshop related topics.

Today, I'm going to be showing the assembly and use of the Portamate PM-1100 universal base kit.

On my previous trip to Dad's, I picked up a large saw with a base that Granddad had made.

I didn't have a permanent location for it, so for expedience, I picked up a mobile base with metal rails.

These metal rails have holes in them in fixed locations for adjustability, but because the holes are in fixed locations, you don't have infinite adjustability.

And so it didn't exactly quite fit the base that I already had. It ended up being about an inch larger than it really needed to be on both the width and length.

I looked around and found the Portamate PM-1100.

This is a hardware kit that has wheels and all the hardware to mount them to a piece of wood.

The piece of wood doesn't come with the kit. You'd make it whatever size you want.

So this allows me to have a base that's exactly the right size for the bases that I already have.

I'll leave an Amazon affiliate link in the description below.

With this design, there's two corners that are designed for the back of the equipment that only roll in one direction.

And there's two corners that are designed for the front with castors that allow you to change direction as you're rolling it around.

The castors are also designed with levers on them so they're up when you're using the tool and it won't roll around and you can push them down, the wheels drop down, lifts the tool off the ground and you can move it.

You supply a piece of wood to connect them at the desired size.

Plywood is usually best for strength purposes.

When I originally bought them, I was planning on just attaching them to the preexisting bases without using any plywood.

However, when I actually got them and tried putting them on, I realized there were toe kicks on the bases that interfered with the hardware raising and lowering mechanism.

So in order to put them where that would work, there wasn't enough material left to attach them to so I ended up going with the plywood anyway.

I cut some plywood left over from previous projects to the desired size, added the hardware to it and attached those assemblies to the bases.

But I'm getting ahead of myself.

Let's take a look at what's in the box and how to assemble them.

In the box are two bright orange pieces that are the levers for the cam activation and two plates to mount the castors to.

There are also four corner pieces and wheels.

Two corner pieces are designed for the rear wheels and two are for the front wheels.

There are also four flat plates that are designed to sandwich plywood between them and the corner pieces to provide extra support.

And all the needed screws, nuts and bushings are in a little baggie.

The rear wheel assembly is straightforward.

Using the appropriate bolt, put it through the axel hole from the inside of the base.

Place a bushing on it, the wheel, another bushing and then a nyloc nut on the outside.

Putting the second bushing on is a bit tricky due to the limited space but holding the wheel flat keeps gravity from working against you.

The front wheel assembly has a few more parts.

First put in the foot rest.

This is what will rest on the floor when the wheel is in the up position, keeping the tool from moving around.

It just screws into pre-threaded holes in the corner piece and is secured with a jam nut once the height is set as desired.

Then put a carriage bolt through the top square hole.

Put a bushing on the bolt followed by the orange piece, flat side up, followed by another bushing and pushed through the other side of the support.

A split lock washer goes on followed by a standard nut.

Put another carriage bolt through the other square hole and then the grey plate.

Note that the plate comes pre-lubricated with some grease.

Be sure to put the grease side towards the orange plate and don’t get it on you.

Push the screw through the assembly followed by another split lock washer and nut.

Finally, the castor can be put through the grey plate and secured with its nut.

This nut has a flanged surface that acts as a lock nut and goes toward the plate.

Next measure your tool base to determine how big you need to make your plywood and cut it to size.

The hardware is designed to work with either 1/2” or 3/4” plywood and comes with different length screws for each application.

Depending on the thickness you use, you’ll have screws left over intended for the other thickness.

With the plywood cut to the correct size, place the wheel assemblies on each corner and mark the hole positions.

Then drill the holes.

I used a drill press but you could use a hand held drill.

Just be sure to get them as straight as you can since there’s another metal piece that needs to match up on the other side.

There is some room for play, so it doesn’t have to have super tight tolerances.

But the closer you can get it, the easier it’ll be to get everything lined up.

Once all the holes are made, it’s time to attach the corner assemblies.

Put the corner piece with the wheel in place, put a flat triangle piece on top with the countersink side up and attach them with the appropriate screws.

Note that the bottom piece has a pre-tapped hole so no nuts are required for this operation.

Get all the screws started first, then make sure the corner assembly is tight to the wood before tightening the screws down.

Repeat this process for all four corners and the base is ready to attach to your tool.

How this is done will vary, depending on your tool.

In my case, I just used grabber screws to attach from the bottom of the plywood up into the bottom of the tool’s case.

My Granddad used 2x4 construction for the base’s frame, so there was plenty of wood to attach to.

You’ll have to figure out the best means of attaching this for your situation and provide your own hardware.

Once it’s attached, all that’s left to do is adjust the rubber feet on the front.

You want to adjust them so they support the weight of the equipment when the wheels are in the up position but are lifted off the ground when the wheels are in the down position.

Once in the desired position, tighten the jam nut so they will stay in place.

And, they’re ready to use.

I’ll see you in this playlist of other shop organization ideas.

And when making things, remember…

Perfection's not required. Fun is!

DIY Sequential Turn Signal Block Diagram

Description

Want more in-depth design information about the sequential turn signals circuit presented in a previous video? In this episode of House of Hacks, Harley shows a high-level diagram and a simple voltage conditioning circuit to convert a switched 12 volt on/off signal to a 5 volt logic signal. This is a follow-up to a question asked in a comment on this DIY sequential turn signal circuit video.

Resources:
Block diagram images and memory layout (GitHub)
Pulse generator circuits (Google search)
Voltage regulator circuits (Google search)
Binary counter data sheet (PDF)
Buffer datasheet (PDF)

Here at House of Hacks we do tutorials, project overviews, tool reviews and more related to making things around the home and shop. 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 Sequential Turn Signal Block Diagram

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

Transcript

A couple days ago on this sequential turn signal video, JTinnon asked if I could share the schematics for this circuit.

I put this together a couple decades ago and honestly cannot remember if I made a schematic for it or not.

I looked in the couple places where thought I might have them stashed and couldn’t find any so I drew out some block diagrams.

I’ll show these right now at the House of
Hacks.

[Intro]

Hi! Harley here.

If you’re interested in workshop projects made out of things like wood, metal and electronics, consider subscribing so you won’t miss a
thing.

In the previous video JTinnon commented on, I discussed the philosophy of design for this project and displayed a couple partial diagrams, but I never showed the whole thing.

In this video, I’ll show the complete, high-level diagram.

And everything I show today can be downloaded from GitHub at the link below.

There are also links to other resources that might be helpful in understanding this circuit.

First, here’s a block drawing of all the functional pieces.

I go into this in more detail in the earlier video, but again in brief, there’s a pulse generator whose output is fed into the input of a binary counter.

The pulse generator can be any circuit producing regular pulses that can be detected by the input of the binary counter.

In my case I used a 555 timer in an astable multivibrator configuration with a variable resistor in order to be able to control the speed.

Two sequential bits on the output of the binary counter are fed in to the least significant bits of the address lines on the ROM.

The output from switches indicating right, left and brake are fed into the inputs on address bits 2, 3 and 4 of the ROM.

The 12v signals coming from the switches are conditioned through some voltage shifters.

Address bits 5, 6 and 7 are unused and tied to ground.

The data outputs from the ROM are fed into the inputs of a buffer chip that is subsequently used to drive display circuitry.

Next, let’s look at the schematic for the voltage shifter since it’s a little bit unique.

The issue is the signal coming from the switches is either 12 volts or nothing.

12 volts is too high for the 5 volt logic circuits.

And the logic gates can't cope with the floating, non-connected switch when it's turned off.

So the 12 volt on/off signal needs to be converted to 5 volts that is either a voltage or ground.

To do this, I used a 5 volt zener diode in a voltage regulator configuration.

This changes the 12 volts to 5 volts.

Next I put in a resistor to ground in parallel.

This ensures that when there’s no connection, the signal goes to ground instead of floating at an indeterminate value.

The voltage for all the logic circuits comes from a 7805-based regulator.

There are lots of schematics for this on the web.

I've left links in the resources section below.

But if I were doing this again, I’d probably use a buck converter for better efficiency.

And here’s how I programmed the memory.

Given there are 5 address lines being used, that means there are 32 memory locations that need to be programmed.

Since the bottom two address bits vary by time from 0 to 3 and address lines 2, 3 and 4 represent switch states that can be from 0 to 7, the whole thing can be thought of as 8 groups of 4.

Each group represents one combination of switch settings and the 4 items in that group represent what lights are on at four points in time.

I hope that gives some additional insight into this circuit design.

I’m thinking about doing a similar circuit that uses an Arduino.

Leave a comment below if this is something you’d be interested in.

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

Until next time, go make something.

Perfection’s not required.

Fun is!

Workshop Organization Systems - Quick and easy overhead bins

Description

Today at the House of Hacks, Harley shows the overhead bin storage that's part of his workshop organization systems. This is a quick and easy do-it-yourself system, taking advantage of scrap materials, to use under-utilized area for shop organization of small items in overhead bins.

Here are the bins I used. (Amazon affiliate link)

Here are some other shop organization tips.

Here at House of Hacks we do tutorials, project overviews, tool reviews and more related to making things around the home and shop. 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 Workshop Organization Systems - Quick and easy overhead bins

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

Transcript

In the comments of a previous video, STLABC requested that I show the overhead bins that are part of my workshop organization systems.

We're going to look at that today at the House of Hacks. Coming at you.

[Introduction]

Hi. Harley here.

Today we're going to talk about one of my workshop organization systems that I use here at the House of Hacks.

STLABC noticed that I had some overhead bins and requested some more details on that system.

My workshop is down here in the unfinished basement in our house and I've got joists for the floor above me that are exposed because it's unfinished.

One day I noticed that the distance between the floor joists is a little bit larger than the width of one of these plastic shoebox sized storage containers.

It reminded me of an idea I'd seen somewhere as I was wandering around the internet.

So I went down to Target and picked up a couple of these containers just to see if it would work.

I had, fortunately, in my spare wood pile, some of this tongue and groove paneling that was left over from a remodel project.

It's the perfect width to just be able to tack into place underneath the floor joists and the handle will rest on each side. I didn't have to do any cutting.

Now, depending on your application, if you have some scrap wood, you can cut it to width after measuring to see how much you need and it's a real easy to put in place storage system.

Using this is really simple.

All you do is lift up, tilt it, and it drops right out.

To replace it, it's just the reverse operation.

Push it up at an angle and it drops into place.

Now, I'm standing on a step stool to be in frame and demonstrate this on camera but because my ceiling is a couple inches shy of eight feet, it's easy enough to do this while standing on the floor normally.

To easily tell what's in each box when I'm standing on the floor, I just have a label that I made with a label maker on the bottom of each container.

I hope that gives you enough details for this particular storage system.

If you have any questions, leave them in the comments below.

There's another video up here where I talk about other organization tips that I use here at the House of Hacks.

Down there are some videos that YouTube thinks you might enjoy.

Until next time, go make something.

Perfection's not required.

Fun is!

Jack stand storage - An easy afternoon DIY project

Description

Wondering about an easy jack stand storage solution? In this episode of House of Hacks, Harley shows garage storage ideas for an easy afternoon DIY project about how to store jack stands.

Here at House of Hacks we do tutorials, project overviews, tool reviews and more related to making things around the home and shop. 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 Jack stand storage - An easy afternoon DIY project

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

Transcript

Today at the House of Hacks, we're going to figure out a better storage system for jack stands.

[Introduction]

Hi. Harley here.

I've been cleaning out the garage and as part of that project, I realized I have some jack stands that I've been storing on the floor and I've got a perfect place right here in the corner of the garage, between the corner of the building and the rails for the doors, to put them.

They'll fit in here perfectly if I can hang them like this.

So the plan is to put a piece of 3/4" OSB in this space because the drywall's really not strong enough to hold the weight of the hooks very securely, I don't think.

And it'll be easier to screw into OSB, plus then I don't have to worry about the jack stands messing up the drywall at all.

So, I'm going to fill this space with some OSB and put some hooks on it and I think...

There's some supports in the bottom here, some braces, that I think should be able to hook onto hooks real easily and they should be able to just hang on the wall like that and just lift right off without any problem.

I've got another style over here that has a triangular base and has a triangular support at the bottom of it that I think will also be able to just have some hooks that hook into that triangular support and I think we should be good to go.

I got the OSB securely attached to the wall with grabber screws into studs.

I picked up some #8 hooks and now I'm just going to drill some pilot holes and screw them in.

The size on mine are seven inches apart. Yours may vary depending on the size of the base of your particular jack stands.

[Drilling]

[Installing hooks]

That's going to work great I think.

Now I just need to get more hooks in for the other jack stands and I'll be done.

That's been a real quick garage project this weekend. It kind of interrupted some other things I was working on but this will be a whole lot nicer going forward.

I've really needed to get these up off the floor where they collect dust and spider webs and everything and take up floor space. This will be a real great addition to the garage.

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

Until next time, go make something.

Perfection's not required.

Fun is!

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!

How to quiet a shop vac

Description

In this episode of House of Hacks, Harley shows how he changed a normal shop vac into a central vac system for the shop.

Associate Links

• Flanged inlet receptacle
• PowerSwitch Tail II

Measuring the efficiency of a centralized shop vac system

Alternate DIY blast gate videos

Background video about the design evolution of the switch

For a written transcript, go to How to quiet a shop vac

Music and sound effects under Creative Commons License By Attribution 3.0.
Intro/Exit: "Hot Swing" by Kevin MacLeod at http://incompetech.com
http://freesound.org/people/musicmasta1/sounds/131385/
http://freesound.org/people/nothayama/sounds/172497/

Transcript

[Vacuum getting stuck between equipment]

[Vacuum tipping over]

[Loud vacuum]

In this episode of the House of Hacks I'm going to show how I made my shop vac easier to use.

[Introduction]

Hi makers, builders and do-it-yourselfers. Harley here.

In general I'm pretty bad at house cleaning. I tend to put off vacuuming and straightening up until it's unbearable. Around the workshop, this is exacerbated by the inconvenience of the shop vac. It has a tendency to tip over on its own cord. It's big and awkward in a cramped space. And it's uncomfortably loud.

I wanted a change based on some requirements: 1) minimal daily setup: it should basically always be ready to use and not take much to clean-up at the end of the day; 2) be convenient when using: I don't want to drag it all over the shop from one tool to another; 3) quiet: I want it to be really, really quiet; 4) inexpensive: I didn't want to spend a lot of money.

So to solve all these issues, I made it into a central vac system. At some point I'd like to get a real dust collection system, but right now that's outside both my money and space budgets.

Today I'll show: the box I built for the vacuum, the way I plumbed it in to the shop and how I turn it on and off. In a future episode I plan to show before and after measurements of both noise and vacuum efficiency and finally some future improvements I'd like to do.

Since noise was a big issue for me, I built this box to hold the vacuum and muffle its whine. In the junk pile from previous projects, I had some rigid insulation foam, softer foam rubber and some scrap 2x2. I figured this would work well as the main components.

I measured the shop vac dimensions, added a couple inches to each side for air circulation and the thickness of the foam.

This gave me the target outside dimensions. I went to the local home store and got two sheets of the cheapest 3/8" sheathing I could find. This is usually used under roofs and siding so it has a lot of visual imperfections, but it's good enough for this use and really cheap. When I got home I sliced up the sheathing and built the box by simply screwing it to the scrap 2x2. It's not pretty or square, but it does serve the purpose.

When I got the sheathing, I also picked up a piano hinge and some casters.

The casters I mounted on the bottom to make it easy to move around and of course I used the hinge for the door to give me easy access to the shop vac inside.

I mounted three spare electrical boxes in one corner on the inside. Two of the boxes go through holes to the back and the other points into the box. I'll get to the details of all that in a minute.

Next I cut up the foam and used spray adhesive to glue it to each of the sides.

Finally, I cut a hole in the side for the hose to run through and a hole in the top for the exhaust vent.

The electrical part has two components. A line voltage side and a low voltage side.

On the line voltage side, one of the boxes pointing to the outside has a male plug on it. This allows me to plug an extension cord into the box. This type of plug is convenient to use on projects like this but I couldn't find one at the normal places I typically get electrical parts. I ended up having to order this online. If you're looking for something like this, search for "flanged inlet receptacle". There's also an Amazon associate link in the description.

The box inside just has a normal duplex plug wired to the plug in the other box. The boxes are connected by a standard conduit connector. Combined, the two boxes provide a clean way to run power through the wall of the wooden box.

I plugged two things into the duplex outlet: a surplus low-voltage wall-wart power supply and this PowerSwitch Tail. The power supply provides low-voltage for the switch. The PowerSwitch Tail is basically a short extension cord with a relay built into it. When a low voltage is applied to these two connectors, it turns on the plug. This allows low voltage devices, like micro-controllers or other digital electronics to easily control line powered devices, like shop vacs.

I put another electrical box pointing to the outside for a remote switch. This is the low-voltage side. I installed a barrel style power connector in the electrical box pointing into the larger enclosure for the wall wart output to plug into.

On the outside of this box I installed a standard RJ-45 connector plate, like we used to use for those old-fashioned telephones. The connectors have four wires. The barrel power connector is attached to two of the connectors on the RJ-45 jack.

The other two lines of the RJ-45 run through the electrical box and go to the relay control connectors on the PowerSwitch Tail.

I then built a little switch box. It has an RJ-45 connector on the side and two switches: red and green. Inside it has a simple flip-flop circuit. Press the green button and the circuit turns on. Press the red button and the circuit turns off. A standard 4-conductor telephone cord connects the remote box on the side to the big box with the vacuum in it. I have a pretty long cord here that allows me to turn this on and off from anywhere in the shop. If you want more details of how this works, please leave a comment letting me know and I'll make another video about it. And if you're interested in the design evolution of this switch, there's a video on my second channel going into those details.

For plumbing, I used 2" black ABS drain pipe. This is pretty close to the diameter of the flexible hose that is standard on my vacuum. I ran a straight section across the ceiling with a couple sections running down in key areas in my workshop. I used sweeping connectors for smoother airflow and minimize places where dust can get caught. I held it all in place with perforated strapping tape and some screws. Most of the connections are just press fit. I didn't want to use cement in case I need to take it apart to clean it out, move it or do other sorts of maintenance. However, the sections that run down had a tendency to fall apart with just the friction fit so I put a short, self-taping screw in each one to hold them together. It's still pretty easy to remove the screw if I need to take them apart.

For the ports, I first looked at blast gates at the local wood working store. They were pretty expensive and not terribly well made. I really didn't think they were a very good value. I thought about making some blast gates of my own. I looked online and found some designs, but they were just more complicated to make than I wanted to deal with and I didn't have all the material I'd need in my scrap bin. So I made my own based on the design of the ports on the house's central vac system.

They're basically a hinged flap with a bit of foam to seal them and some magnets to hold them closed. They're epoxied to a standard plumbing fixture. The flex hose stays in with a press fit.

So that's pretty much it for the construction details. How well does it all work? I'll cover that in a future part 2 episode.

If you're interested in part 2 or other DIY type videos of this nature, click the Subscribe button and YouTube will let you know when they're released.

If you have any questions or comments, please leave them below. I'd love to hear from you.

Until next time, go make something. It doesn't have to be perfect, just have fun!