Electronics and Embedded Programming V3

[Ploo]

How difficult would it be to make a bluetooth capable device so that I can pair it with a mobile phone and have them communicate?

[DrLuke]

[QUOTE=Ploo;35660859]How difficult would it be to make a bluetooth capable device so that I can pair it with a mobile phone and have them communicate?[/QUOTE]

Not very much, you can buy ready to go bluetooth modules with an UART in/output for 15$ tops on ebay

Just look for BTM-122, BTM-222 and similar

[gamingrobot]

[QUOTE=DrLuke;35646990]Doesn't the beagleboard have GPIO pins?[/QUOTE]

yes, but I wanted to keep the system modular

[Ddrl46]

[QUOTE=Ploo;35660859]How difficult would it be to make a bluetooth capable device so that I can pair it with a mobile phone and have them communicate?[/QUOTE]

If you can solder: [url]http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711?item=2[/url]

If you can't solder / are lazy: [url]http://www.dealextreme.com/p/jy-mcu-arduino-bluetooth-wireless-serial-port-module-104299?item=1[/url]

[Xera]

[QUOTE=ddrl46;35664562]If you can solder: [url]http://www.dealextreme.com/p/wireless-bluetooth-rs232-ttl-transceiver-module-80711?item=2[/url]

If you can't solder / are lazy: [url]http://www.dealextreme.com/p/jy-mcu-arduino-bluetooth-wireless-serial-port-module-104299?item=1[/url][/QUOTE]

The first one you linked does not have the supporting circuitry necessary to use the module. The second one also has a voltage regulator so you can run it on a wide range of voltages instead of just 3.3v.

[DrLuke]

They both have no RF shielding

[Fishstick]

Ever try to talk someone through building and troubleshooting a modulated Tesla coil kit over voice chat? I'm surprised he isn't dead yet.

[Ddrl46]

I finally got my 6E2 Magic Eye tube working!
My messy desk
[img_thumb]http://i.imgur.com/H8gDc.jpg[/img_thumb]

The test subject
[img_thumb]http://i.imgur.com/Sk3jP.jpg[/img_thumb]

Victory!
[img_thumb]http://i.imgur.com/jwSYh.jpg[/img_thumb]
[img_thumb]http://i.imgur.com/gKXxL.jpg[/img_thumb]

[VistaPOWA]

and then his Arduino got fried.

[Chryseus]

Oh well at least is was nothing of value.

[Ddrl46]

[QUOTE=VistaPOWA;35687851]and then his Arduino got fried.[/QUOTE]

Had to find some way to get rid of it.

[demoguy08]

Why the Arduino hate?

[Chryseus]

[QUOTE=demoguy08;35688434]Why the Arduino hate?[/QUOTE]

Arduino is fine for beginners looking for an introduction into microcontrollers but otherwise it's not that great, the Arduino code libraries are rather bloated and slow and I still don't really see the purpose of the addition of a second chip to the Arduino Uno.

The Arduino itself is not what annoys people like myself and ddrl it's the crappy community that surrounds it, consisting largely of people who don't understand electronics to any significant degree and put very little effort into improving their knowledge.

Then you have the people wanting to make money from the uninformed Arduino users, either directly by selling components, shields and other stuff at grossly inflated prices or indirectly by providing circuits and videos (most of which the content is stolen from someone else) with very little attempt made to provide a decent explanation, some examples would be Afrotechmods, Kipkay, Makemagazine and others on Youtube.

I'm fine with people genuinely wanting to learn electronics, but those that are just doing it to muck around or look cool I strongly dislike.

[DrLuke]

You're seeing the whole thing from a completely wrong perspective Chryseus:
There's a community of people with next to no knowledge of electronics who don't put any effort into improving that situation willing to pay a lot of money for stuff.

To sum it up:
We should develop some hardware and get rich together

[Chryseus]

Great idea, only one slight problem, we can't rip-off anyone who reads this thread now.
... or maybe we can.

Come get this amazing Arduino compatible shield, contains a few cheap components, all for the low low price of $30!

[DrLuke]

[url]http://arduino.cc/forum/[/url]

[ROBO_DONUT]

I like the idea of open hardware :\

Also, you have to look at it this way:
They're generally small developers making limited runs of items with limited demand.

It's basic economics. If you're stuck serving a tiny niche, you have to crank the price up just to make a modest profit.

It's not like TI or whoever, who are churning out parts that go into mass production for consumer goods. They can afford it, because they ship such large volume.
Or even TI dev. boards, like the MSP. They're probably selling at a loss, because it's not the boards they care about. They want to develop brand recognition with the next generation of EEs.

[Chryseus]

[QUOTE=ROBO_DONUT;35689491]I like the idea of open hardware :\

Also, you have to look at it this way:
They're generally small developers making limited runs of items with limited demand.

It's basic economics. If you're stuck serving a tiny niche, you have to crank the price up just to make a modest profit.

It's not like TI or whoever, who are churning out parts that go into mass production for consumer goods. They can afford it, because they ship such large volume.
Or even TI dev. boards, like the MSP. They're probably selling at a loss, because it's not the boards they care about. They want to develop brand recognition with the next generation of EEs.[/QUOTE]

Open hardware is great, I hope people continue to release their designs for others to use and more importantly learn from.
And to some degree it's quite understandable for small companies to sell their product at relatively high prices but sometimes this is rather ridiculous when all you get is a few components mounted on a PCB with some headers.
One good example of it being done right is Dave Jones and his uCurrent, it may cost $50 but your getting a very useful bit of kit that's well designed and packaged.

[Zero-Point]

[QUOTE=Chryseus;35688932]Arduino is fine for beginners looking for an introduction into microcontrollers but otherwise it's not that great, the Arduino code libraries are rather bloated and slow and I still don't really see the purpose of the addition of a second chip to the Arduino Uno.

The Arduino itself is not what annoys people like myself and ddrl it's the crappy community that surrounds it, consisting largely of people who don't understand electronics to any significant degree and put very little effort into improving their knowledge.

Then you have the people wanting to make money from the uninformed Arduino users, either directly by selling components, shields and other stuff at grossly inflated prices or indirectly by providing circuits and videos (most of which the content is stolen from someone else) with very little attempt made to provide a decent explanation, some examples would be Afrotechmods, Kipkay, Makemagazine and others on Youtube.

I'm fine with people genuinely wanting to learn electronics, but those that are just doing it to muck around or look cool I strongly dislike.[/QUOTE]

I like afrotech. :saddowns:

[DrLuke]

Afrotech is great at explaining, but for my taste he only barely scratches the surface of explanation. He could often get into more detail.

[MIPS]

[QUOTE=Chryseus;35688932]some examples would be Afrotechmods...[/QUOTE]

Wasn't that site built to be a joke?

[ROBO_DONUT]

[QUOTE=MIPS;35690300]Wasn't that site built to be a joke?[/QUOTE]

It was a joke-electronics site about ten years ago. I remember giggling about it in high school.
Everything was horribly half-assed, but he occasionally did something that was cool until it started a fire. Like the inductive mouse mat, which worked until it melted the mousepad to his desk. Or the drink cooler that worked until he started getting zinc poisoning. Or the hard drive speakers which sounded like shit.

Good site, fun times, and I'm sure he's learned a lot by now (you don't break shit for ten years without learning [i]something[/i]).

[Zero-Point]

[QUOTE=MIPS;35690300]Wasn't that site built to be a joke?[/QUOTE]

He has a Youtube channel where he actually DOES explain some electronics principles.

[Implosive]

My first circuit of any complexity. Using mostly salvaged parts.

[img_thumb]http://filesmelt.com/dl/IMG_20120423_210204.jpg[/img_thumb]

[MIPS]

For those who turn old HP test tools into clocks, they can go eat shit.

[IMG]http://i11.photobucket.com/albums/a166/ballsandy/100_2760.jpg[/IMG]

I have been looking for a frequency counter for a while. This should fit the bill.

[DrLuke]

That looks sexy as hell

[Lapsus]

Finally pulled apart my main impusle-buy from the surplus store and had a look at how the display worked. I thought it was a nice long VFD, but instead it's [url=http://parts.digikey.com/1/parts/678727-intelligent-disp-4char-5x7-red-dlr1414.html]some write-only memory linked to 5x7 arrays of tiny LEDs[/url]. You write ASCII to the register for whichever specific cell of the chip and it does the rest.

I guess the next step is getting that keypad going, but I'm already out of pins, and I don't particularly want to add a second Arduino to this, or spend any money. I'm thinking that it'd make for a pretty awesome control panel if I were to go build a CPU in my FPGA though.

[img]http://imgkk.com/i/u231.jpg[/img]

// Buttonpanel Display Test

// Pins
int Data  = 2;
int Clock = 3;
int Latch = 4;
int Address[6] = {5, 6, 7, 8, 9, 10};
int Write = 11; // Pull low to write to memory

                         //1111111111222222222233333333334
// Variables      1234567890123456789012345678901234567890
char Message[] = "Hello World! Lapsus was here. It works! ";
int Temp = 0; // I don't know what to call variables like this

void setup()
{ 
  pinMode(Data, OUTPUT);
  pinMode(Clock, OUTPUT);
  pinMode(Latch, OUTPUT);
  pinMode(Write, OUTPUT);
  digitalWrite(Data, LOW);
  digitalWrite(Clock, LOW);
  digitalWrite(Latch, HIGH);
  digitalWrite(Write, HIGH);
  
  for (int i = 0; i < 6; i++)
  {
    pinMode(Address[i], OUTPUT);
    digitalWrite(Address[i], LOW);
  }
}

void loop()
{
    for (int i = 0; i < sizeof(Message); i++)
    {
      digitalWrite(Latch, LOW);
      shiftOut(Data, Clock, MSBFIRST, Message[i]); // Load the character into the shift register
      digitalWrite(Latch, HIGH);
      
      Temp = 3 - (i & 3); // Grab the lower two bits of the address and invert them
      
      // Char select
      digitalWrite(Address[0], bitRead(Temp, 0));
      digitalWrite(Address[1], bitRead(Temp, 1));
      
      // Chip Select
      digitalWrite(Address[2], bitRead(i, 2));
      digitalWrite(Address[3], bitRead(i, 3));
      digitalWrite(Address[4], bitRead(i, 4));
      digitalWrite(Address[5], bitRead(i, 5));
      
      
      digitalWrite(Write, LOW);
      //delay(1); // The arduino is slow enough to get away with no delay here
      digitalWrite(Write, HIGH);
    }
  while(1)
  {
    // We're done, really.
  }
}

[masterburner]

[QUOTE=Lapsus;35704121]Finally pulled apart my main impusle-buy from the surplus store and had a look at how the display worked. I thought it was a nice long VFD, but instead it's [url=http://parts.digikey.com/1/parts/678727-intelligent-disp-4char-5x7-red-dlr1414.html]some write-only memory linked to 5x7 arrays of tiny LEDs[/url]. You write ASCII to the register for whichever specific cell of the chip and it does the rest.

I guess the next step is getting that keypad going, but I'm already out of pins, and I don't particularly want to add a second Arduino to this, or spend any money. I'm thinking that it'd make for a pretty awesome control panel if I were to go build a CPU in my FPGA though.[/QUOTE]

Shift registers? 74hc165 for parallel in, serial out and 74hc595 for parallel out, serial in.

[Lapsus]

[QUOTE=masterburner;35714706]Shift registers? 74hc165 for parallel in, serial out and 74hc595 for parallel out, serial in.[/QUOTE]

Well yeah, but I'd have to spend money to get more of them so it's not likely.

[DrLuke]

High quality chinese soldering job:

[img]http://i.imgur.com/a2MiU.png[/img]