# Electronics



## DearLeaderJohn (Aug 12, 2013)

Anyone into electronics as a hobby? I've just ordered an arduino uno r3, and I'm interested to see what others round here use and make!


----------



## fatboy (Aug 12, 2013)

I love messing about with electronics - got a few college courses under my belt about it all from setting up a few simple circuits to building my own Sky decoder when they first started out and before they knew a lot about scrambling signals 

Fast forward a few years where I did nothing I now have a son who is getting into it so we have some bits and pieces and a few raspberry pis and have a muck about every so often to see what we can do (or break)


----------



## MartinD (Aug 12, 2013)

Always loved dabbling though that came from my Dad. He was part of the team that designed the very first barcode scanners 


I remember as a kid starting out making crystal radios. Can still remember how to this day!


----------



## notFound (Aug 12, 2013)

I've always loved tearing electronics apart and reusing old electronics etc., and figuring how they work. I've always had time and money as the limiting factor for building on this hobby.


----------



## DearLeaderJohn (Aug 12, 2013)

Great to see quite a few people with a passion for Electronics.



Infinity said:


> I've always loved tearing electronics apart and reusing old electronics etc., and figuring how they work. I've always had time and money as the limiting factor for building on this hobby.


That's why the Arduino platform is great, you can pick up an Arduino board for around £7 and add your own components. Programming is done in C or C++ and it's fairly quick to grasp


----------



## MannDude (Aug 12, 2013)

As a kid, yes. It was a hobby that I wish stuck with me. Basic things like the school project where you use a D battery to create a switch to power a lightbulb, that was fun. I remember as a youngster getting a gift for Christmas that I spent so much time with, I wish I remembered what it was called as i'd probably enjoy it today too, haha. Essentially was a big board with springs all over it, and you'd connect wires to different areas to do different things.

Been wanting to do more with my Raspberry Pi too, instead of just stuff I can do with a normal computer. Should do somethign that requires soldering.


----------



## drmike (Aug 12, 2013)

The Pi's and Arduino sure are active with electronics projects.

I never got into electronics due to the cost when you break something and lack of role models/teachers with related experience.

Closest I get is my random solar projects, related power, battery pack building, some DC sensors.  Most of what I do is off the Asian shelf repurposing of things --- often using things for purposes other than what were originally intended for.


----------



## shawn_ky (Aug 12, 2013)

MannDude said:


> As a kid, yes. It was a hobby that I wish stuck with me. Basic things like the school project where you use a D battery to create a switch to power a lightbulb, that was fun. I remember as a youngster getting a gift for Christmas that I spent so much time with, I wish I remembered what it was called as i'd probably enjoy it today too, haha. Essentially was a big board with springs all over it, and you'd connect wires to different areas to do different things.


They still sell this at RadioShack. Various sizes. And now various kits.


----------



## Jade (Aug 12, 2013)

buffalooed said:


> The Pi's and Arduino sure are active with electronics projects.
> 
> I never got into electronics due to the cost when you break something and lack of role models/teachers with related experience.
> 
> Closest I get is my random solar projects, related power, battery pack building, some DC sensors.  Most of what I do is off the Asian shelf repurposing of things --- often using things for purposes other than what were originally intended for.





shawn_ky said:


> They still sell this at RadioShack. Various sizes. And now various kits.


*Maandude goes to Radioshack and buys one*


----------



## MannDude (Aug 12, 2013)

shawn_ky said:


> They still sell this at RadioShack. Various sizes. And now various kits.


What are they called? I had one when I was, I don't know, 6 or 7. 8 at the oldest. I just remember making it chirp, light this thing up, light that thing up, etc.


----------



## stim (Aug 13, 2013)

I started dabbling about 18 months ago by building some DIY synthesizer kits. It's addictive. Currently I am building a polyphonic synth with keyboard (my own design), and a nascent monster modular system. 

Wish I had more time.


----------



## MartinD (Aug 13, 2013)

MannDude said:


> What are they called? I had one when I was, I don't know, 6 or 7. 8 at the oldest. I just remember making it chirp, light this thing up, light that thing up, etc.




Used to have these too. Started with a smaller red one.. then got a larger blue one. Loved those things!


----------



## HalfEatenPie (Aug 13, 2013)

So... um....

what are they?  I never had one of those before.  But I did have a breadboard with wires, light bulbs, resistors, batteries, clock, etc.  Made a stop light system a long time ago.


----------



## DearLeaderJohn (Aug 13, 2013)

HalfEatenPie said:


> So... um....
> 
> what are they?  I never had one of those before.  But I did have a breadboard with wires, light bulbs, resistors, batteries, clock, etc.  Made a stop light system a long time ago.


Well my Arduino arrived today and I've started messing around with it. It's a single-board microcontroller.




The Arduino has been programmed to fade the LED via PWM (Pulse width modulation); this is a very simple beginner project (some people have made sentry guns detecting friendlies etc).

The Arduino is programmed in a language based on C/C++ and is quite simple, for example the code used for this project is:


```
/*
Fade

This example shows how to fade an LED on pin 9 using the analogWrite() function.
*/

int led = 9; // the pin that the LED is attached to
int brightness = 0; // how bright the LED is
int fadeAmount = 5; // how many points to fade the LED by

void setup() {
  // put your setup code here, to run once:
  // declare pin 9 as an output;
  pinMode(led, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly: 
  // set the brightness of pin 9;
  analogWrite(led, brightness);
  
  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;
  
  // reverse the direction of the fading at the ends of the fade;
  if (brightness == 0 || brightness == 255) {
    fadeAmount = -fadeAmount;
  }
  //wait for 30 milliseconds to see the dimming effect
  delay(30);
}
```


----------



## MartinD (Aug 13, 2013)

There are lots of Arduino - Pi projects out there, a lot of them for the likes of 'eye in the sky' type projects.


----------



## splitice (Aug 13, 2013)

MartinD said:


> Used to have these too. Started with a smaller red one.. then got a larger blue one. Loved those things!


I had that exact one! It was great but I ended up getting sick of it as I already knew how to solder at that time and who can beat circuits made from the leads of other components at that age?

I owe my father for teaching me to solder and all those things.  He used to be a phone techie at the exchange so a bit of electrical engineering was part of his job (and part of his night schooling at the time).

Pretty sure learning electronics teaches you to think logically at a young age, leads to programming. Most of the programmers I know can solder or are interested in electronics in some way or another.

I am yet to do anything to my Raspberry Pi yet, lack of inspiration struck less than 24hrs after it arrived. Recently however I've been thinking about getting building a serial interface for it and using it to PWM (via a serial PWM chip) control the fans for my servers based on profiles etc. TBD


----------



## notFound (Aug 13, 2013)

DearLeaderJohn said:


> Anyone into electronics as a hobby? I've just ordered an arduino uno r3, and I'm interested to see what others round here use and make!


Out of curiosity, where did you buy all of your goodies from? Since we're both in the UK. ;-)


----------



## DearLeaderJohn (Aug 13, 2013)

Infinity said:


> Out of curiosity, where did you buy all of your goodies from? Since we're both in the UK. ;-)


Well I got a starter kit so I could do the basic tutorials, cheapest place in the UK is on ebay. So I ordered:

The Funduino Uno R3:

http://www.ebay.co.uk/itm/Arduino-Compatible-Funduino-Uno-R3-ATmega328P-PU-Board-with-Free-USB-Cable-/181181225989?pt=UK_Computing_Other_Computing_Networking&hash=item2a2f3e1c05

and a starter kit:

http://www.ebay.co.uk/itm/120947620583?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Can't complain about the seller, items came next working day


----------



## MartinD (Aug 13, 2013)

Just bought one


----------



## DearLeaderJohn (Aug 13, 2013)

MartinD said:


> Just bought one


You wont regret it! Been having a blast with mine today but giving it a rest for now before my brain overheats


----------



## xmob (Aug 13, 2013)

Infinity said:


> Out of curiosity, where did you buy all of your goodies from? Since we're both in the UK. ;-)


If you're in the UK, you can't go wrong with http://www.coolcomponents.co.uk.

Be warned, you can never buy just what you went there for.  There's always one or two other items that end up in your shopping cart.


----------



## shawn_ky (Aug 13, 2013)

MannDude said:


> What are they called? I had one when I was, I don't know, 6 or 7. 8 at the oldest. I just remember making it chirp, light this thing up, light that thing up, etc.


They are called.... wait for it.... wait for it.... Electronics Learning Lab... 

http://www.radioshack.com/product/index.jsp?productId=3814337  Here is one version for sale. There are several that range from building an AM radio, FM Radio, etc up to more expensive ones..


----------



## pcan (Aug 13, 2013)

I have both the Arduino Uno and a couple of Raspberry Pi's. Both boards are fun to use, but lately I use the Raspberry Pi almost exclusively. My projects needs the ethernet interface: the Arduino ethernet shield is somewhat expensive and has limited capabilities; the Raspberry Pi has a far worse general purpose I/O, but the ethernet jack is standard on Model B board and the computing power is quite sufficient to power a real web server.

I am now testing the Raspberry Pi camera module. The time-lapse feature could be a useful addition to the server room monitor application I described on one of my previous posts here; I am now figuring out the best way to feed the pictures to a standard application such as Motion. I will also use further I/O pins to monitor the status of some telecommunication equipment. A cheap photoresistor is connected to a Raspberry GPIO pin, and a fixture keeps it in contact with the equipment LED. A cronjob polls the status each minute. If the LED lights up, a email is sent. I am already using this contraption to monitor a industrial machine; the manufacturer recomended monitoring solution was quoted over 1000 EUR.

A further project will be the monitoring of old UPSs that have no network monitoring board. I am testing some interfaces ordered at http://www.yoctopuce.com/, specifically the bistable relay and the watt-meter.

Electronics is mostly a hobby for me now, but I am actually a electronic engineer; in 2000 i switched career to the IT field after more than 10 years on analog electronics and microcontroller interfacing. Digital electronics is mainstream, but I still found interest on analog projects. I also used to restore electron tube vintage radios and amplifiers; the designers had to be resourceful to overcome the limitations of that early technology, so schematics are always interesting to check. In early times, the manufacturer always shipped the schematic diagram togheter with the radio; sometimes it was on the rear panel itself. This way, repairs could be made easily and economically. The net result is that a 1950 radio or Hi-Fi amplifier can be repaired today with ease - after some standard maintenance, you can turn it on and it works. I strongly doubt that any of the current consumer electronics device will be still working in 2070, and you will not have any meaningful source code of the VLSI chips inside to attempt a repair.


----------



## MartinD (Aug 14, 2013)

Look what arrived this morning


----------



## DearLeaderJohn (Aug 16, 2013)

After finishing up cleaning some IPs, I figured I could burn some time messing around with the Arduino tone library...so I present to you

http://sdrv.ms/15NxP6v

Circuit is simply a jumper wires from digital output 8 to the + side of the speaker via a 100ohm resistor. Code is at http://pastebin.com/xeyHgzrg pitches.h is at http://pastebin.com/c9gx1tcu


----------

