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1  Community / Bar Sport / Re: Mouser price error of offloading old stock? on: April 19, 2014, 02:07:20 am
It looks like this is perhaps a "label" containing regulatory approvals and such, that you would stick on the outside of your product if it happened to contain one of their (much more expensive) modules.  Other vendors have more accurate descriptions.

Well spotted, I had looked and looked at this and never clocked the label bit before. I knew it was to good to be true  smiley-red
2  Community / Bar Sport / Mouser price error of offloading old stock? on: April 18, 2014, 11:20:12 am
While browsing Mouser site for modem controllers I came across this item that seemed very cheap  at £0.299 each. Being a good citizen I clicked the 'See an Error' button and reported the price seemed to be moved 2 decimal places to the right from where I would expect it to be. I got in reply a quote confirming the £0.299 price.so can only assume the price is right.
Alas it's not quite what I'm looking for but for eBay sellers I would think there is a profit to be made here.
3  Using Arduino / Project Guidance / Re: Struggling with my BMW IBUS projects. Serial.read related issues. on: April 18, 2014, 11:10:12 am
I agree with Robin, the only way to do this properly is to read all messages check there CRC to confirm your still synced to the data stream and discard messages that are of no interest to you.
A quick look at IBUS protocol shows the first byte is sender ID so if you do become out of sync then look for a particular sender ID to try synchronizing your reads again.
4  Using Arduino / General Electronics / Re: Voltage trigger on: April 18, 2014, 07:51:44 am
You don't say if the 12V is AC or DC but if it's DC then a simple voltage divider will lower the voltage to a level the Arduino can read without being damaged.
5  Topics / Education and Teaching / Re: Clearing serial buffer solved on: April 18, 2014, 07:46:47 am
Would it be better to write a small function to clear the buffer instead of doing serial.end/serial.begin as this may fragment memory.

Code:
void serialFlush(){
  while(Serial.available() > 0) {
    char t = Serial.read();
  }
}   
6  Using Arduino / Programming Questions / Re: Best way to read in an analog trigger signal on: April 18, 2014, 05:43:34 am
Input High Voltage   Min:(0.7Vcc)  -  Max:(Vcc+0.5)
That's for data pins when VCC <= 2.4V or for XTAL pin at >= 2.4V
I think for the UNO @5V pin low is 1.5V and pin high is 3V any voltage between these is grey area.
7  Using Arduino / General Electronics / Re: Not getting square wave output from SQW pin of DS1307 on: April 18, 2014, 04:30:58 am
I have connected a pullup resistor of 10KOhm from pin7 to VCC.
I am using the library written by alvarojustenhttp://forum.arduino.cc/index.php/topic,59256.0.html.
That RTC library is very basic. I recommend this library as it's served me well over the years and has built in SQW commands.
8  Using Arduino / General Electronics / Re: Not getting square wave output from SQW pin of DS1307 on: April 18, 2014, 02:33:10 am
Do I have to enable the square wave output explicitly by program?(The datasheet says it all).
Yes you need to enable it in the control register. Bit 4 is SQWE (square wave enable) and bits 0-1 are the frequency required. For what you want bits 0 & 1 need to be cleared and bit 4 needs to be set. Any good RTC library will have functions to do this, what library are you using?
9  Using Arduino / Programming Questions / Re: SMPTE timecode Reader programming help on: April 18, 2014, 02:07:44 am
Hi, is there any chance of being able to post a schematic or a link of the hardware you are using to connect to the ardunio?
The SMPTE used in broadcast video machines timecode in/out is just an audio signal so you would need to use a similar circuit as used to capture audio signals if this is your source.
A good description to be found here
10  Using Arduino / General Electronics / Re: Help identifying ground lead and signal of switch. on: April 17, 2014, 03:30:00 pm
Don't connect 5v, gnd and a signal pin as you will damage your arduino.
The three terminal are common, normally open and normally closed just like you find on relays.
How you wire the switch depends on what your using it for. Give us more details and we can help.
11  Using Arduino / Programming Questions / Re: Best way to read in an analog trigger signal on: April 17, 2014, 04:59:31 am
Quote
The trigger for the arduino is an analog (I'm assuming) output signal of 5V (100mA) generated by the mp3 player that lasts for the duration of the audio track.
What MP3 player are you using and do you have links to data sheets for it. If your MP3 player is offering a GPI output as it seems from your description then reading on a digital pin should work. Remember you may also need to connect grounds.

If the output is an audio signal then you may be dealing with negative voltages that Arduino pins don't like so be careful.

If the signal is truly analogue (and is positive only) then maybe a RC Circuit will smooth out the fluctuations so you get a more stable analogue reading.
12  Community / Website and Forum / Re: Dealing with spam on: April 17, 2014, 03:30:54 am
The only downside will be you cannot describe your problem in the subject header so people will eventually get bored of clicking every "Hi, this is my first Thread" and few if any people will bother reading there new posts after a time.

Many of them have crap titles anyway. Having an enforced title may actually make them think about the usefulness of titles.
True, I don't tend to read threads with non descriptive/crap titles.

Quote
Until they adjust the robots to send the first magic post
I am assuming the title is important to someone trying to advertise something or trying to get you to click some dodgy link.
Not always, some titles even have the spam word in them but another more subtle technique I have seen on here is to post a simple smoke blowing post but put the spam URL in the tagline.
13  Using Arduino / Project Guidance / Re: Create wireless magnetic knob on: April 17, 2014, 03:23:26 am
This control looks like a form over function gimmick to me but it possibly uses 5 hall sensors to detect the tipping action and rotation.
Another way to detect rotation is using something like an AS5030.
14  Community / Bar Sport / Re: Maplin UK. on: April 16, 2014, 12:24:16 pm
Some UK suppliers that I have used, apart from technobotsonline. I cannot comment on returns as I have never had to do so.
My favourite from the list is hobbytronics as they have given me superb service every time I have ordered from them. I also order quite a bit of stuff from eBay and have a few shops/sellers that I return to as there service is also good and cheap.
For some larger projects I order components from Mouser, CPC & RS but you have to remember the prices are not VAT inclusive.

http://www.coolcomponents.co.uk/catalog/
http://hobbycomponents.com/index.php/
http://www.hobbytronics.co.uk/
http://www.phenoptix.com/
http://proto-pic.co.uk/

http://www.technobotsonline.com/
15  Using Arduino / Project Guidance / Re: NEED HELP STUCK!!!!! on: April 16, 2014, 05:15:10 am
I have to turn the dome of my windmill according to the direction of wind for which i need some motor mechanism can you please tell me which motor to use for this task ..............
What is the mass of the dome your trying to turn as this will greatly effect the choice of parts.
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