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166  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Connecting Ardiuno Usb to a Pocket PC / Smartp on: July 10, 2008, 05:47:09 am
For bluetooth comms, look for the bluetooth serial port protocol (SPP) on your mobile phone.

If it is supported you will (probably) be able to establish a connection with an Arduino BT and send data.

The trouble with this kind of development is that there are unknowns at both ends, the phone and the Arduino. You might want to buy an inexpensive bluetooth GPS module which uses SPP and learn how to establish a connection from your phone to that, then move onto doing it with an Arduino.



167  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: ArduinoBT problem on: July 08, 2008, 08:16:56 am
I use 3 AA cells - like you, 4.5Volts.  

The swithcing regulator will bring that up to 5V for the AVR and a linear regulator will drop it to 3.3V for the bluegiga module. Do measure these voltages on your board with a multimeter, if only for peace of mind.

There are a couple of capacitors either side of the linear regulator that will be big enough to put a probe on.

The reset pin of the BT module is connected to pin 7. Waggle that pin in code to do a reset.

There is an article about reprogramming the BT module here:

This has never happened to me, so I'm afraid I can't help much.

168  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: ArduinoBT problem on: July 08, 2008, 05:01:28 am
-is it possible to burn out only the bt module ?

I've not done so, but I would think it probable.

- can it be a hardware problem in arduinoBT boards? (should the max be 3.3v (because bt module?) and not 5.5v? )

The Arduino has a switching regulator on board which generates 5V for the AVR chip. This feeds into a linear regulator that produces the 3.3V for the BT module. You should be able to measure these voltages with a meter.

- have any of u use the arduinoBT for a long time? more than 24 powered on? the bt module turned less shinny?

I have had mine running for several days at a time without noticing any changes. (Though it could be I'm not looking for them, so haven't seen them).

I hope this helps a little,

169  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Windows Application on: July 07, 2008, 04:39:43 am
I don't know if the Smartphone will work with Arduino directly. On an ordinary Windows PC you need to install a driver that makes the Arduino board appear as a virtual serial port. You would probably need a driver like that on your phone before you can connect the Arduino board to the phone. I don't know if such a driver exists for the Smartphone OS.

Just to add a little ... you only need a driver on the Windows PC if you are communicating through USB.  

There are a some serial Arduinos which have rs-232 interfaces on them or you could use the software serial library to send data to the phone.


170  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: hi speed event detection on: July 02, 2008, 09:28:23 pm
The break will be 1 microsecond max.

I'm not sure of your application, but you might find you can do what you want without a micro controller. Using something like a d-type flip flop will enable ypu to detect breaks in a circuit.

A counter like the 4017 will enable you to count breaks in the circuit.

You could always connect the output of the d-type to the arduino.

171  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Getting components in the UK on: June 23, 2008, 04:19:06 am
I don't recall, to be honest, but I don't think so.

I've only been charged the £8 by the post office once. I bought a few bits from ladyada totalling about £30 IIRC. The £8, in addition to whatever VAT / duty I had to pay, certainly impacted the price. I may have done things differently if I had known.

172  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Getting components in the UK on: June 19, 2008, 11:33:03 am
For small amounts this is collected by the post man, although sometimes they don't bother.

And watch out -- the Post Office adds an £8 charge for collecting the vat and/or duty from you.

173  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: How do I control an OutputPin through telnet? on: May 28, 2008, 05:59:43 am
It would be best if I could actually pass single lines of raw code to the Arduino for it to then execute. Example: I would enter "digitalWrite(13, HIGH)"

However you do the comms, (USB or xportm etc) the AVR will be getting the commands through the serial port. You wold set up the serial port appropriately, and use to grab a byte/char at a time.

As for send lines of raw code for the AVR to execute, this isn't possible. The C code is compiled before being loaded to to the AVR.

However you acn always write a parser to interpret the commands you send and act on them accordingly. If it were me  I would shorten what you send from "digitalWrite(13, HIGH)"  to something like "dw13h" or "dw13l". It would still be human readable and easy to parse by your program.

174  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: noob (arduino bt and switching) on: May 19, 2008, 08:59:48 am
It would be usual to drive a relay from the 595 using a transistor.

What is it you are hoping to switch?  There may be better ways than using a relay.

175  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Simple power question - I hope on: April 25, 2008, 04:37:59 am
EDIT: Can't the Arduino BT be powered with 7.4 Volts ?  Check that out first :-)

No - 5.5V max.

176  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Accelerometer to estimate speed on: May 12, 2008, 03:32:40 am

Just throwing my two cents in but I believe an object traveling at constant velocity will have 0 acceleration.

Indeed, but if you have kept track of the velocity up til that point you know the spped that the thing is moving at.

I do believe in the days before GPS, vehicle tracking was done using accelerometers.

It wouldn't take long to connect an accelerometer to and Arduino and try it out. It would be interesting to know how good/bad it works.


177  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Reading Mux Analogue Inputs on: April 21, 2008, 09:16:00 am
I'm not sure where you are getting this 8* from.

The procedure I would take is as follows:

1) Select an analogue input through the mux
2) Wait a short preiod of time for the effects of switching the mux settle down.
3) Read the analogue value.
4) Select the next analogue input through the mux.
5) Goto step 2.

This will be the fastest you can read all the inputs. You may want to read them less often (it depends on your application) so you may want to set it up so that you read a new value every, say 25ms. This will give time for the Arduino to do other things besides reading pot values.


178  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Salvage anything from dead Arduino BT? on: April 21, 2008, 09:07:25 am
I killed an Arduino BT by giving it too much power.  Can any of the parts be salvaged?  Can it be repaired by replacing a part?

Unlucky. What power did you apply?  Did anything smoke or pop?

As this board is predominately surface mount, I doubt they'd be anything that can easily be rescued.

If the failure was such that the 3.3V supply didn't pass anymore than 3.3V to the Bluetooth radio, you may be able to desolder and re-use that, but it looks tricky to do.

You may well be able to repair it - it depends what failed and how - and how good your eyesight is.


179  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Motor control on: April 17, 2008, 03:38:58 am
You should be able to control it in one direction with a transistor.

You'll need a resistor to limit base current from the Arduino output or the transistor will fail. Probably silently so you won't know it has failed.

This page: motor control has some sketches to show how it is done.



180  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Problem about the pass key of Arduino BT on: April 18, 2008, 08:51:32 am
I had some issues getting the ArduinoBT connected.

I think there are some issues with the XP USB drivers. Also, in my case I had used 2 different bluetooth dongles at different times and one used the windows driver the other installed some other drivers.

In the end I went through and deleted all the com that were related to USB. Then I searched and found the Arduino-BT and paired to it successfully.

I selected the BT board in the IDE (I was using v0010, but I understand v0011 has some BT improvements) and set the baud rate.

It took a little time for me to get the time between pressing the reset button and clicking the download button on the IDE before it worked - and it did give an odd error message when it didn't work - but it has been working ok since.

I hope this helps a little.


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