Welcome to DIY Tryin. Build something new. I'm Patrick Norton. I'm Michael Hand. We were going to bring you
the most amazing confluence of aluminum gas welding
and lemons today. But that failed horribly. Yes. Yes, it did. So instead, Arduinos. Yay! What's an Arduino? So Arduino is a
microcontroller that you can program to do
tons, infinite things. It's a controller or
a microcontroller. There's, like, 32,000
variations of these, from BASIC PIC Stamp
through Arduino. Some people use Raspberry Pi. I'm thinking the cover of
Make Magazine this month has 300,000 different
controllers inside of it. I mean, a controller
controls things, right? Yeah, exactly. So like I said, it's
something that you can program to do a
whole range of things. So in this case, we're
going to show off how to control
high-powered applications, or do high-powered
applications, with this little low-powered Arduino. And what's crazy is by combining
some kind of controller, like the Arduino, and some
software you can probably download off the
internet, probably will have to download
off the internet, you can make things do
things-- like automate a dorm-room
entertainment system, or make sure some lights
get turned on every time your garage is opened,
or that a song plays every time your cat
sits down on its bed. It's just-- the limit
is your imagination. Exactly. Controller boards, you can pick
them up at Radio Shack now. You got yours off of-- I got mine off of
eBay, I think, for $12. Because it's cheap and they all
seem to work, in my experience. This is good. So what's with the
Flying Spaghetti Monster homage of wiring? OK, so beyond the
microcontroller, we also have this relay board. This is an eight-channel
board, so that means that we can power eight
different things this way. Well, you can turn eight
different things on or off. On or off, so a relay
board is super old school, in that it's just like a
remote-controlled switch that this is a physical switch
that's switching on and off. There's a chance every time
you turn the headlights on in your car, a relay is
actually doing the switching. I mean, these are
basically-- as far as electronics are concerned,
this is Stone Age technology. So these are cool, that it's
looking for a 5-volt signal. And when it gets that
5-volt signal, it turns on. And by turning on, I mean
it closes the connection, and then closes the loop. Yeah, you send
voltage in this end. It does magic. It closes the
switch at this end. And I love reading the specs--
10 amps, 250 volts AC, 10 amps, 30 volts DC. That means 120 volts,
220 volts, as long as it's not higher than 10
amps, 30 volts DC, as long as it's not higher
than 10 amps-- anything up to that maximum. That's really awesome. That's a lot of
juice to work with. Yes. So the way I have
this set up is that I have a ground going
to the relay switch. And then I have
pins 2 to 9 here-- that equals eight, right? I think so. Yeah, pins 2 to 9, that
those are controllable, so that I can say
OK, send a signal. And then when it gets that
signal, then it'll turn on. Hence the controller
part of the Arduino, but there's more purple wires. Yes, so this-- I
have it set up so that it has an
external power supply. Because from what I understand,
with these big, eight-channel boards, the Arduino doesn't have
enough power or enough amperage to turn all of them
on or off at a time. So I don't want to
burn out my board. So I have this
external supplier that will supply the power to
actually close the gates. Like, one to four relays you
found that you can supply off the board without
burning it out. Yeah, exactly. Then things like sketchy. Then I just was scared. What are we controlling, and
how are we controlling it? Is that where the
software comes in? This is where the
software comes in. So right now, we have some
LED lamps plugged in here. And that's a 12-volt load. This is 12 volts,
which is still way more than the Arduino can do. It can do five volts. And then we also have
an AC application here. We have a fan plugged in here. Don't worry. This is safe, not
like last week-- hopefully, we think-- or
the week before last week. So let's jump into
the software, and I'll show you how this is
actually connected. Cool. How this is powered. First, you need the
actual Arduino software, which you can find
at Arduino.cc. It's downloads for, I think,
Mac, Linux, everything. Intel Galileo. So once you have
that downloaded, you'll see you have this
cool little software here. And the nice thing
about Arduino especially is that smart people
have figured out how to do whole lots
of things already. Yay. So I found on this Arduino dash
info dot Wikispaces dot com, someone already wrote
code to control a relay. AKA Arduino power. Yes, so I just straight
copied and pasted this code into our Arduino software here. I'm going to say it,
because it's my job-- is that legal, Michael? Probably, they put
it on the internet. It's generally
accepted and cool. OK. Just saying. So the way you actually
send code to the Arduino is that you make sure you have
it connected to your computer. So this just has a USB cable. So first of I'll compile the
software, and then I'll upload. So if you're
getting errors here, you probably have to select the
port that you want to be on. Things are happening. In this case, I have the USB. But it worked. And as you can see, this
code cycles through. It turns on all the switches,
and then turns them off. It doesn't have to cycle them. It's just what this particular
application is doing. Yeah, so this is
very basic on how you get an idea of what things
in the code you actually need. And then from there, you can
start playing with the code. So in this case, it's setting
to be, like, a one-second delay. If we want to get crazy,
we can set it to be, like, 40 milliseconds. Which, when I-- You'll break my fan. So I just sent it. It'll take four seconds. And then, oh, awesome. And the thing I love
about the mechanical relay is you can hear
them switching over. So I'll just let this go
for the rest of the episode. (DRUMMING) OK, maybe not. A little annoying. So instead I have this
code that I kind of expanded a little bit. It's definitely not
the cleanest code ever, but I'm sorry everyone. It works. So another cool thing
you can do with Arduinos, is-- that last application,
you could take this. It's all self-contained. It doesn't need to be
connected to a computer. So you can just
power the Arduino and it will cycle through
that forever, if you want. You could have a
crazy light display, or you could use it to control
neon light transformers or something. Yeah, but if you want
to have it so that it's listening for something, so
now I brought in a serial port. So that the Arduino
has a port that you can send commands to,
and then doing that, it'll do whatever
you set it to do. So I have it set up so that it's
listening for different keys. So if I hit one, it'll
turn on the first relay. And if I want to turn it
back off, I hit one again. So switching physical
universe things on and off your
computer, I don't know why I still find this
incredibly fascinating. So the serial port can
be very, very useful if you want to send
commands to your Arduino. And hey, while I'm still here,
you should check out Audible. Go to audiblepodcast.com/diy
and you'll get a free audio book of your choice, and you'll
help support the show. Nice segue, huh? So part of the reason you
got involved with the relays was so that you could do stuff. We're going to do
something kind of exciting in the next few
weeks with hard science again, not controlling lights,
but controlling something else. Screaming may be involved. We'll go more in
depth with that, but I can show you a little--
just to finish this off, I have it set up so that I have
a Python script here listening for numbers. So I could be, like, bum bum
bum bum bum bum light show. Ladies and gentlemen,
would you like to learn how to make
things do things, and just learn how
to get your diy on? Please subscribe to DIYTryin.com
or YouTube.com/DIYTryin. I love how it
through to the fan. That was beautiful. At DIY Tryin on the Twitters. And rumor has it, there
may even be a place to hang out with us on Reddit. And if there is, you'll
see it down below. And if you're on YouTube,
please comment down below. I'm Patrick Norton. I'm Michael Hand. We'll see you next
week on DIY Tryin. What did that look like, Liz? It looked really good. Oh, my god.
