/diy/ - Do It Yourself

Get a few paired phototransistors and LEDs. Make a car that follows a line on the ground made with electrical tape.
Bonus points for running everything on 12V battery power.

>>758598
This is final project-tier for some lower division CS classes.
Also obligatory don't buy something you don't know what to do with.

>>758600
How the fuck is that final project tier.
All you need to do is point the LED at the material and log the value you get on the photoresistor from the reflection, if value =x then you're on the line, good.
Then all you've got to do is repeat the process on a couple of locations (left, right middle) and program some if statements that decide if the robot needs to move to the left or to the right or stay in the middle depending on the values of the resistors.

Not op, but >>758598 reminded me, I was just looking the other day for a power source for a small project I'll work on soon (hopefully).
I'll need a 12v source for a fan (a PC fan actually), the rest will be work on Arduino's 5v.
What's the best solution to do something portable for this? Do you guys usually stack a few AA batteries, or do you buy lithium battery with a step up converter, or what?
I don't really need a lot of mAh, just something to be as lightweight as possible.

>>758608
>as lightweight as possible
switching buck regulator and a few 18650s

>>758607
A lot of people don't realize it, but lower division CE and CS majors (first and second year) are mostly made up of people who have never touched a wire or programmed in C before. So it is an appropriate final project for first years and others.

>>758622
This. You can't assume any prior knowledge.
My boss said he taught an EE lab and on the third lab, someone raised his hand and said his terminal block was defective. They only cut slots going one way and forgot the second perpendicular slot. His screwdriver wouldn't turn it.
He had to explain to him there was a slotted/flatblade screwdriver and a Phillips.
Kid thought Phillips was just the brand.
Lab 4 was then tool day. He brought tools, meters and scopes.
The rest of his teaching career, that was lab 1.

Something that was enjoyable for me was using an Arduino for motor control. Wasn't the best system, but it was rewarding for me. All you need is a DC motor, a sensor (such as an encoder), and a motor control circuit, such as an H-bridge.

Either that or look at various sensors that are out there, and learn how to use them, then put them into a larger system such as robotics, or some home application such as lighting.

If you're interested in low level processor stuff, learn to use the ATMega since it's a relatively simple processor.

Could also try looking to communications. This could be sending a message from one Arduino to another, get a shield and send wireless communications to the computer, an XBox controller, or another Arduino. Learn how to use the serial communications with the computer at a lower level so that you can do the same with other systems later on.

The idea of an Arduino (at least to me) is to control a larger system. Look around and look for something that you're interested in and try to think of a way to improve it or to design your own.

>>758608
use a 5v fan?

>>758622
Well I guess that's true, but if someone actually decides he wants to do something on his own he's instantly ahead of the plebs that default to not giving a fuck about school.

I should know, in my first year I had trouble understanding a linear PSU circuit we had to make for our final project.
But once you start to actually do shit outside of the program it gets much more fun.

>>758573
I'm currently building a sort of mold type thing to help the construction of an 8^3 RGB LED cube. I'm using the arduino to prototype code and circuitry, then I'll move to a standalone atmel chip with the bootloader.

I've got in use a arduino based system with a thermocouple temperature measurement inside the chimney and 1-wire measurements on the pipes around the boiler. There is another 1-wire measurement system on different layers of the 3000 liter system that is used for long term energy retaining. The central unit is a RPI with OpenHAB, and communication is done with mqtt protocol

PS: fuck captcha on a mini-laptop. Choose the bread when the whole thing keeps resetting? fuck you moot

>>758750
pls post pics!
I wanna make an arduino weather station or sumthing eventually.

>>758608
A lot of my projects are 12v for motors / lights and 5v for microcontrollers and other logic. A salvaged PC power box will provide both for stationary projects. For portable I get a 12V SLA or car battery and use one of these 5v switching regulators. They're for putting USB chargers in cars. You can find them at most car parts stores.

>>758808
Here's the ~20 yo boiler, upgraded. The thermocouple sensor has in itself 8mm threads, so all that was needed to attach it to the chimney was a 7mm steel drill bit and a threading tool. When I get around to it I'll attach those loose wires to run along the walls/pipes to make it more tidy. The house has cat5 going to most of the rooms (dad had the idea of smart home 10 years ago), so networking things is easy. DS18B20 sensors (1-wire) need just ground, +5 and a data pin from the arduino for all of those sensors, so running out of IO is not going to happen. The connections are soldered onto a perfboard with a male header, so if I need to replace the arduino I just need to plug it out and take out the screw holding it in place.

The code uses ready arduino libraries for the MAX6675 thermocouple, 1 wire and mqtt so I didn't need to reinvent the wheel or anything. For just doing this I could do with just a single arduino doing the web part too instead of RPI+OpenHAB, but I'm also planning to add lighting, alarms, etc. on the system too.

>>759002
Printscreen came up empty on Chrome, and like picrelated on FF, but thats the general idea. When the top layers start approaching 50-60 C its time to fire up the boiler again. When its burning I can see if everything is OK or if I need to go adjust the airflow or something.

>>758573

I've made a few things:

- clock with alarm and temperature/humidity gauges
- AM radio
- electronic scope
- flac player
- ap wire reader

just fyi, you can make some nice cases with hobby wood (usually found somewhere inside a home depot as 12 inch by 48 inch sheets) if you drill out all the places for buttons with a drill, and if you apply some nice finishing. Even made some nice custom ones that I sold on ebay for like $200 each

>>758618
>>758646
>>758865
Thanks guys, I'll look into those options. I doubt a 5v motor will be good enough. The batteries sound quite promising and they seem to be cheap enough.

OP posts a 'have crap, no imagination, wat do' and nobody has told him to stuff it up his arse? I am /diy/sappoint.

>>759046

the last time I did that I got b& for "quality of posts"

>>759046

>UH GOSH GUYS WHY nobody acting like le edgy prick >:((((((((((
Fuck off, this is an awesome hobby, I like to help everyone however I can.

>>759046
I'm guilty of starting one of these "have shitloads of x, wat do"
Sometimes by no virtue of our actions we come into several items of a particular kind. We may not be as experienced or knowledgeable in respects to the objects or their many uses/worth, but we want to make the best of it. That's were /diy/nosaurs come in. We've got a pretty diverse group here, even though it seems lately we've been getting more and more immature edgy posters, it's likely that there's someone browsing that can provide input worth more than what the OP would have done without. Just read a few posts in this thread. He's already thinking of a few projects he can do with what he has.
.
.
which will lead to a vicious cycle where he keeps spending money on more electronic components, and he spirals down into hoarding surplus materials and devices until they clutter all his living space.

>>758573

nice...

i think im gona get into this closer

i thisnk of rapsb with this module and wiring my whole house and making lights/temp/alarm shit whatever

may be cool but lots of work idk if im skilled enough

>>759678
When dealing with security systems, always use negative logic.

My favourite arduino project:
http://vimeo.com/44526977

I'm currently working on.

>>759046
yeah, imagine what wouldve happened if he said "raspberry pi" instead of "arduino"..

>>760023
Solder them together and cram them up your ass?

>>758573
Hi OP.
I am currently building a laser x-y cutter. This monday I also ordered my materials to make a nixie clock with in-14 tubes. There are tons of cool stuff you could make, depending on your skill level and the amount of money you are willing to spend.
So one question for you OP, what is your budget and what fascinates you (I adore nixie tubes myself, some machines, and fancy lighting too)?

>>758573
learn how to drive servos and build a robot, by this I mean learn how to use someone else's code to drive servos. Once you do that, it's pretty easy to make robots.

I used an arduino equivalent to make a walking robot this last weekend. It wasn't that hard.

>>758598
why the heck would you need a 12V battery pack for a tiny car? Just use a 9 volt battery. For driving small motors this should be more than enough.

>>758573
are you fucking serious? To build a line following robot you don't even need a computer.

>>759557
my nigga

i'll be lurkin

Oh speak of the devil, first time checking out this board and there's a thread on it.

I actually just found out about the Arduino today on a random trip to MicroCenter.

Any particularly noteworthy stuff I should know about them? Currently my knowledge of microcomputer shit like this is limited to recognizing the name "Raspberry Pi." And some trivial familiarity with the MIPS architecture, if that's relevant.

Feel free to get technical on the level of "shit a guy who just graduated in CS can understand" if you want.

Sorry if this is more of a /g/ question or anything.

>>758573
Sup princess/diy/, I did this really rudimentary arduino project at metro Detroit's Penguicon last year where I learned how to make a tiny badge out of an arduino board with little lights. I've been considering taking on arduino and robotics as a side-hobby. How fucked am I? No electrical experience here, just programming shit.

>>760927
Write code.
Code makes pins go high or low ("connect" to + or - aka Vcc or ground).
Connect a pin to a LED.
Watch the magical smoke be freed from it's dungeon.
Buy new arduino.
Buy resistors this time.

In other words, everything's pretty simple if you're only doing basic stuff. Just remember polarity and current limits. Everything else you'll learn along the way.
Oh and datasheets, learn to love them if you want to get into electronics.

>>760955
>>759002 Here, I know fuck-all about electronics, just that its usually blue and hurts if you touch it. Planning on learning more about it though. As far as programming goes, I have experience with Java and C++ (and some others too), and if you are used to one of the easier languages with Arduino there is no one holding your hand and telling its all going to be OK if you fuck it up with memory allocation. It's all in C baby, from the 70's when writing code you actually had to do stuff.

>>761021
Arduino is actually C++.

>>761043
It's not like C++ isn't C with features stapled onto it or anything.

>>761043
You mean Arduino supports OOP?

>>761043
So I could actually go with the OO way? Not that it would suddenly make it all better, just wondering.

>>761043
>C++
absolutely disgusting

>>761054
Yes, but you can't really program an AVR like you would a desktop. See the book "Real-Time C++" by Chris Kormanyos for tips on using C++ in a resource-constrained environment (most examples in the book are done with an AVR).

>>761049
Maybe back in 1983, but they diverged pretty quickly.

>>761065
Yea, I imagine there would be some differences. My experience with something like this is with Qt on Symbian, which was pretty much dead the moment Nokia chose MS (and swallowed the poison pill, but such is the life in business). Downloaded the book, looking forward to reading it.

>>761071
>My experience with something like this is with Qt on Symbian, which was pretty much dead the moment Nokia chose MS