Electronics and Embedded Programming V3

[Zero-Point]

[QUOTE=kp3;36804294]I'm trying to regulate the speed of two 7-12 volt DC engines.
I was told in this thread [url]http://facepunch.com/showthread.php?t=1198296[/url] that i could use PWM to do this.

My question is, As I already asked there, Can i use an Arduino to do this or will i need to set up a circuit for this? Will it make the engine very jumpy and cause a lot of vibrations as opposed to letting it run regularly?

I know I'm asking a lot, But could you give me any hints on a good way of doing this? I'm basically wanting to create a way of steering without using a servo or any gears (Because I have neither available). Thanks in advance.[/QUOTE]

With an appropriate motor driver, PWM should be perfectly fine for determining motor speed. It won't be jumpy, all PWM does is effectively reduce the voltage applied to the motor by proving more or less power to the motor on average in a given time frame.

[kp3]

[QUOTE=Zero-Point;36804554]With an appropriate motor driver, PWM should be perfectly fine for determining motor speed. It won't be jumpy, all PWM does is effectively reduce the voltage applied to the motor by proving more or less power to the motor on average in a given time frame.[/QUOTE]

I am completely new into electronics, Why is an engine driver required?

[Falcqn]

[QUOTE=kp3;36804955]I am completely new into electronics, Why is an engine driver required?[/QUOTE]

You need a driver circuit for the motors because of how much current they pull. Microcontrollers are pretty delicate, and usually have a relatively low max. current rating before they fry which is generally much lower than what your motors will be pulling from your power supply.

In response to your earlier question; yes. You can use an Arduino for controlling the motors provided you use some form of driver circuit and don't just connect the motors to the pins of the Arduino directly.

[Chipset]

[QUOTE=kp3;36804955]I am completely new into electronics, Why is an engine driver required?[/QUOTE]

Why it just so happens I made a guide for this, presented in glorious page-stretching goodness.

[img]https://dl.dropbox.com/u/59112523/how2ardweeno.png[/img]

For more advanced motor driving like if you want it to change direction and stuff, look up H bridge.

[editline]17th July 2012[/editline]

Also here's a good video on inductive spiking:

[media]http://www.youtube.com/watch?v=LXGtE3X2k7Y[/media]

[ben1066]

[QUOTE=Falcqn;36806822]You need a driver circuit for the motors because of how much current they pull. Microcontrollers are pretty delicate, and usually have a relatively low max. current rating before they fry which is generally much lower than what your motors will be pulling from your power supply.

In response to your earlier question; yes. You can use an Arduino for controlling the motors provided you use some form of driver circuit and don't just connect the motors to the pins of the Arduino directly.[/QUOTE]

The maximum is normally about 20ma.

[Chryseus]

[url=http://www.falstad.com/circuit/#%24+1+5.0E-6+10.20027730826997+38+5.0+50%0AR+144+224+112+224+0+3+200.0+5.0+0.0+0.0+0.5%0Aa+208+240+288+240+1+5.0+0.0+1000000.0%0A172+144+256+96+256+0+6+0.5999999999999996+5.0+-5.0+0.0+0.5+Voltage%0Ar+176+256+176+320+0+100000.0%0Ar+176+224+176+160+0+100000.0%0Ag+176+160+176+144+0%0Ag+176+320+176+336+0%0Aw+176+256+144+256+0%0Aw+176+256+208+256+0%0Aw+208+224+176+224+0%0Aw+176+224+144+224+0%0Ag+528+304+528+320+0%0Ar+432+240+480+240+0+220.0%0At+480+240+528+240+0+1+-4.753844557689471+0.7649638462645698+100.0%0Aw+528+304+528+256+0%0Al+528+112+528+160+0+0.0010+1.9276384618386997%0Aw+528+160+528+224+0%0AR+528+80+528+48+0+0+40.0+5.0+0.0+0.0+0.5%0Aw+528+80+528+112+0%0Ad+496+160+496+112+1+0.805904783%0Aw+496+160+528+160+0%0Aw+496+112+528+112+0%0Aw+320+240+288+240+0%0Ac+432+112+432+160+0+1.0000000000000001E-7+-0.5188084039540399%0Aw+432+160+496+160+0%0Aw+432+112+496+112+0%0Aw+320+240+432+240+0%0Ax+88+94+261+100+0+24+PWM+Generator%0Ax+97+115+253+118+0+12+You+use+your+arduino+for+this%0Ax+574+140+651+144+0+18+DC+Motor%0Ax+292+97+520+100+0+12+Protection+diode+and+smoothing+capacitor%0Ax+541+277+665+281+0+18+NPN+Transistor%0Ao+15+32+0+33+5.0+3.2+0+-1%0Ao+12+32+0+35+10.0+0.1+0+-1%0A]A more visual example of PWM driving a DC motor[/url]

[kp3]

Saw that guide when i found this thread, It's pretty good. Taught me that I had to use a diode.
Didn't realize that was what you'd call an engine driver though, thanks.

I ordered some new parts (Diodes and potentiometers).
They'll probably arrive tomorrow so I'll try it out then.

[DrLuke]

[QUOTE=kp3;36809442]
Didn't realize that was what you'd call an engine driver though, thanks.
[/QUOTE]

That's not really an motor driver, it's just a transistor. There are dedicated motor driver boards/chips that allow you to easily control a motor to spin in both directions with just 2 pins and have all the necessary protection circuits built in, and they also allow you to use far greater voltages with ease.
An example for such a motor driver would be the L239D, very easy to use, next to impossible to blow up.

[kp3]

Should I really need such a thing for a tiny engine?

[Tw34k]

[QUOTE=kp3;36810340]Should I really need such a thing for a tiny engine?[/QUOTE]

A similar question would be 'I'm going to plow this toothless hooker I meet downtown, I'm almost positive she has super herpies. Should I really need to wear a condom?'

Also

Engine:
[IMG]http://media.treehugger.com/assets/images/2011/10/GM-1.4-turbo-engine-001.jpg[/IMG]

Motor:
[IMG]http://site.nitroplanes.com/exceedmotors/63M18b.jpg[/IMG]

[DrLuke]

[QUOTE=kp3;36810340]Should I really need such a thing for a tiny engine?[/QUOTE]

It entirely depends on what you want to do with the motor.

[kp3]

I just want to have two of them to drive themselves, a breadboard and the arduino.
A 50V diode should be sufficient, right?

[DrLuke]

Well, with the L239D you could control both motors in forwards and backwards direction and conveniently power it directly off a battery.

[thetree]

[QUOTE=DrLuke;36811955]Well, with the L239D you could control both motors in forwards and backwards direction and conveniently power it directly off a battery.[/QUOTE]

How many amps can the L239D handle? I'm also trying to get into electronics with an Arduino and want to power some DC motors. Not interested in forward/reverse, so would I be able to just use 1 pin instead of 2 per motor?

Thanks.

[Chipset]

if ever you have questions about a part just google the datasheet.

[DrLuke]

[QUOTE=thetree;36812172]How many amps can the L239D handle? I'm also trying to get into electronics with an Arduino and want to power some DC motors. Not interested in forward/reverse, so would I be able to just use 1 pin instead of 2 per motor?

Thanks.[/QUOTE]

600 mA at up to 36V per channel.

And yes, you would just need to ground the other control-pin.

[editline]17th July 2012[/editline]

Also you might be interested in this: [url]http://wiki.bildr.org/index.php/L239D[/url]

[KGS]

Does anybody know what the difference is between the nominal power and the music power? I am messing around with some old Hitachi HS-E38 speakers and i can't figure out what the difference is.

[Chryseus]

[QUOTE=0lenny0;36813347]Does anybody know what the difference is between the nominal power and the music power? I am messing around with some old Hitachi HS-E38 speakers and i can't figure out what the difference is.[/QUOTE]

I'm not completely sure if I'm correct but the nominal power is the RMS power and the audio power is the same but with an audio signal, then again with audio gear it could mean anything.
SPL is a much more appropriate measurement of sound power.

[Tezzanator92]

Music power is the power the speakers can take with music audio playing though it (It is also sometimes referred to as "programme") This will be somewhere between the RMS and Peak values.

Nominal power isn't something I've seen often with the gear I deal with but I can only assume they mean RMS. You really only want to pay attention to the RMS value.

SPL/Sensitivity (Usually expressed as "xdb @ 1W/1M") is used to ascertain the sound output of the speaker at a given distance taking into account coupling effects if you are using multiple speakers. You still need a power rating to determine how much power you can actually feed into them, and from that determine your max SPL.

For a 45W RMS, 75W Music speaker It's probably choose a 60W Amplifier so I have the headroom.

[LoneWolf_Recon]

Isn't RMS power what matters when it comes to determining the actual volume? Like with dBu, etc?

[Torquil]

Looking to grab an Arduino board but I'm entirely new to electronics, would this book be a good purchase?
[url]http://www.coolcomponents.co.uk/catalog/getting-started-with-arduino-book-paperback-p-543.html[/url]

[BuG]

[QUOTE=LoneWolf_Recon;36771883]Been working on learning Buck converters for about a week and half now, and my attempts at building a decent Buck converter have lead me nowhere. I'd like some advice please, the video is pretty self explanatory.

[video=youtube;XFZPNVMJ3Ic]http://www.youtube.com/watch?v=XFZPNVMJ3Ic[/video]

Here's a schematic of my attempt:

[img_thumb]https://sites.google.com/site/lonewolfscircuits/sitefiles/Buck%20Converter%20Attempt.png[/img_thumb][/QUOTE]

I know I'm late to the party, but I may be able to help you out.

First of all, you inductor looks like a choke? If you want to pull, well, any real current out of your buck converter, you need an inductor with a relatively thick wire, as in low ESR.

And are you sure the signal that goes to the gate of your MOSFET is clean, and powerful enough to drive it? That was what really got me almost every time when I started out messing with SMPS's, but I didn't use dedicated IC's either.

If it's not powerful enough, you could/should add a transistor buffer, made with a npn and a pnp transistor (to pull it high/low), to a small resistor with a small capacitor in parallel with it.

[Chryseus]

[QUOTE=Torquil;36826534]Looking to grab an Arduino board but I'm entirely new to electronics, would this book be a good purchase?
[url]http://www.coolcomponents.co.uk/catalog/getting-started-with-arduino-book-paperback-p-543.html[/url][/QUOTE]

I'd suggest learning the basics of electronics first, there is plenty of info in the op.

[yngndrw]

[QUOTE=Tw34k;36810491]Engine:
[IMG]http://media.treehugger.com/assets/images/2011/10/GM-1.4-turbo-engine-001.jpg[/IMG]

Motor:
[IMG]http://site.nitroplanes.com/exceedmotors/63M18b.jpg[/IMG][/QUOTE]
[quote]en·gine/ˈenjən/
Noun:
A machine with moving parts that converts power into motion.
A thing that is the agent or instrument of a particular process: "exports used to be the engine of growth".[/quote]
Both of those images are "engines".

[LoneWolf_Recon]

[QUOTE=yngndrw;36829222]Both of those images are "engines".[/QUOTE]

[QUOTE]mo·tor
   [moh-ter] Show IPA
noun
1.
a comparatively small and powerful engine, especially an internal-combustion engine in an automobile, motorboat, or the like.
2.
any self-powered vehicle.
3.
a person or thing that imparts motion, especially a contrivance, as a steam engine, that receives and modifies energy from some natural source in order to utilize it in driving machinery. [/QUOTE]

[Chryseus]

[QUOTE=yngndrw;36829222]Both of those images are "engines".[/QUOTE]

Engine is a rather broad definition that can mean any kind of engine be it combustion or electric.
It's often a good idea to be specific about what [b]kind[/b] of engine you're talking about, in the case of the lower picture it's a brushless DC induction motor.

Most people (myself included) restrict the term engine to combustion engines or complete units.

[TTSDA]

I have a little experience on electronics (Fiddled around with my arduino and some sensors) but now I want to get started for real.
I would like opinions on this DealExtreme shopping list, I also need a soldering iron, but not sure which one to get.

[IMG]http://i.imgur.com/He6s9.png[/IMG]

[LoneWolf_Recon]

[QUOTE=TTSDA;36831974]I have a little experience on electronics (Fiddled around with my arduino and some sensors) but now I want to get started for real.
I would like opinions on this DealExtreme shopping list, I also need a soldering iron, but not sure which one to get.

[IMG]http://i.imgur.com/He6s9.png[/IMG][/QUOTE]

Any good 30W soldering Iron will do for you(inb4 hate, RadioShack 30W irons are good if properly maintained). If you want to you can get you a full soldering station(I can't advise any good ones though)

[Chipset]

Those copper clad PCD's are for etching, unless you know how to etch pcb's and have etching supplies you probably want to build up your projects after breadboarding on these:

[url]http://www.dealextreme.com/p/prototype-universal-printed-circuit-board-breadboards-brown-10-pack-132929?item=14[/url]
[url]http://www.dealextreme.com/p/prototype-universal-printed-circuit-board-breadboards-yellow-10-piece-pack-139802?item=24[/url]
[url]http://www.dealextreme.com/p/prototype-universal-printed-circuit-board-breadboards-green-brown-10-piece-pack-136887?item=26[/url]

These are cheap and pretty low quality, you can get better ones made from fiberglass like these:

[url]http://www.dealextreme.com/p/double-sided-glass-fiber-prototyping-pcb-universal-board-3-x-7-5-piece-pack-131730?item=50[/url]
[url]http://www.dealextreme.com/p/double-sided-glass-fiber-prototyping-pcb-universal-board-5-pack-142733?item=42[/url]
But they're more expensive.

The ones I linked I found are among the best value packs I found, they also sell larger ones and in different size packs but one of the 10pc packs should last you about a half dozen projects.

[ben1066]

[QUOTE=chipset;36834551]Those copper clad PCD's are for etching, unless you know how to etch pcb's and have etching supplies you probably want to build up your projects after breadboarding on these:

[url]http://www.dealextreme.com/p/prototype-universal-printed-circuit-board-breadboards-brown-10-pack-132929?item=14[/url]
[url]http://www.dealextreme.com/p/prototype-universal-printed-circuit-board-breadboards-yellow-10-piece-pack-139802?item=24[/url]
[url]http://www.dealextreme.com/p/prototype-universal-printed-circuit-board-breadboards-green-brown-10-piece-pack-136887?item=26[/url]

These are cheap and pretty low quality, you can get better ones made from fiberglass like these:

[url]http://www.dealextreme.com/p/double-sided-glass-fiber-prototyping-pcb-universal-board-3-x-7-5-piece-pack-131730?item=50[/url]
[url]http://www.dealextreme.com/p/double-sided-glass-fiber-prototyping-pcb-universal-board-5-pack-142733?item=42[/url]
But they're more expensive.

The ones I linked I found are among the best value packs I found, they also sell larger ones and in different size packs but one of the 10pc packs should last you about a half dozen projects.[/QUOTE]

The better ones really are unnessecary for prototypes. Also, if you ever want to get PCBs made, Seeed Studio and iTead Studio are cheap but Chinese and only do 10 at a time. DorkBot PDX do 3 and are higher quality, but more expensive.