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16  Using Arduino / Project Guidance / Re: Alt-Az Tracking Device - Astronomy Help! on: August 14, 2014, 11:13:48 pm
two user inputs, one being altitude (Right Ascension) and the other being azimuth (declination), and then move the telescope to the desired input.

I think what you have done here is ably summarise the difference between an astronomer and a mechanical engineer. The first thing you need do is go back to your lecturer and ask him to recapitulate his instructions. While you are at it, you might discreetly drop the buzzwords "equatorial coordinates". If he looks blank, you will know that he doesn't know what he's talking about either.

What you appear to be looking for has been done a gazzillion times and is called a GoTo tracker whereby you can hop from one star to another in short order and thence observe the star as it it is tracked by turning the telescope on a (buzzwords) polar shaft that rotates to (buzzword) sidereal time. I believe these are two two separate operations. The polar shaft rotates through the night, while the telescope gets up to is antics thereon at your discretion.  You will be faced with quite a bit of maths to do this but it will be about a million times less than you would face using AltAz coordinates.

I reckon an Arduino would be an excellent choice for all this and you will surely find help here from the stepper motor gurus, but you would be better off first checking Sky and Telescope magazine for a better understanding of what you are up against, and what your lecturer is not telling you.
17  Using Arduino / Project Guidance / Re: controlling a droid phone with arduino - how do i do it? on: August 14, 2014, 10:33:03 pm

I took your advice and went on ebay and ordered these two thing,s I hope they are the correct item (s) I would need for this job?

http://www.ebay.com/itm/200924726178?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

and this

http://www.ebay.com/itm/310646216582?_trksid=p2060778.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

and one (the item with the cable) came the other day.

Ok, how exactly do I connect them or make them (especially the one with the cable) communicate with my
arduino unio?


The two devices are essentially the same, as will be apparent when you look closely.  The first is an HC-06 and the second an HC-05 sans backboard. If you thought you were saving money on the HC-05, you probably didn't. You can get blank backboards on eBay for a dollar or so.

You might find the following background notes useful


http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino
18  Using Arduino / Networking, Protocols, and Devices / Re: Bluetooth HC-05 & ArduDroid - Hello World on: August 14, 2014, 10:08:06 pm
This has me thinking maybe the TX on the HC-05 is shorted out/fried? Is there a way I can test the TX on the HC-05 using a multimeter?


A magnifying glass might be the first choice. Somebody has had a solder bridge across the pins of the breakout board, and it was easily fixed.

You might find the following background notes useful

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino
19  Using Arduino / Networking, Protocols, and Devices / Re: How to use arduino ehernet? on: August 14, 2014, 10:03:59 pm
Is it better to use Uno and buy a Shield?

A Uno and a shield is probably a lot cheaper. An Ethernet shield will also work fine on a Mega.
20  Using Arduino / Sensors / Re: Arduino Due with DS18B20 on: August 14, 2014, 09:59:37 pm
Also i have try parasite and normal mode with different code/librarys.

The same connection(with 5 Volt ) and code works on  a Uno without problems.

There is no connection between the code/libraries and the methods of applying power.  The DS18B20 is kosher for 3.0 to 5.5v, so that should not be the problem per se, but I get the impression that that using parasite power with 3v brings its own problems. In short, parasite power is a not a good idea, and is more likely than ever to be the kiss of death if you do it from 3.3v. I bet you haven't got a good reason to use parasite power, and it would be best avoided to solve this problem. I believe others have used the Due OK.
21  Using Arduino / Project Guidance / Re: Can two Arduinos read one sensor? on: August 11, 2014, 10:08:25 am
A Mega should handle that, and you are likely to need one for the memory eventually anyway.

It seems that touchscreens typically confine themselves mainly to pins 22-52, and I can only see eight pins for the rest, as you can put the temp sensors on a one-wire bus.
22  Using Arduino / Project Guidance / Re: Getting Started on: August 10, 2014, 09:36:19 pm
best things I should buy to maximize my learning and not waste money?

The best thing is free. It's a subscription to this forum.

If you have no idea what you want to do and just want to fiddle, you can hardly go wrong with a Uno starter kit. If you already have a goal, a kit is likely to mean you will be just buying stuff you don't need, to the point of being a diversion, and you will be better off getting the trends from the forum before you buy anything.
23  Using Arduino / Project Guidance / Re: Can two Arduinos read one sensor? on: August 10, 2014, 07:25:55 pm
Somebody is probably due to come along with a better answer for you, but just a suggestion, you could have one Arduino read the sensor, and have that Arduino output the data to the other. That way, both can use the data. I understand this probably isn't the most efficient way, but something to play with whilst waiting for somebody more experienced.

It could be a long wait.........

I submit that having one Arduino pass data to another would not only be the most painless and least wasteful way of doing this, but might actually have some value,  and the waiting time would be better devoted to better researching, and explaining, why you would need two Arduinos in the first place. The only instance I can think of is where the first reads a sensor and passes data to the second, which acts as a display repeater. This is more or less what Marshiewoo is saying, but it means that the two Arduinos serve different purposes and can be of different types - and cost.

My sensor stuff is all on a Mega running on wall power but, I while am developing the remote on a Uno, I think a Teensy or something, on batteries, would suffice.
24  Using Arduino / Networking, Protocols, and Devices / Re: Question About Debugging a Serial RX Issue on: August 09, 2014, 10:13:51 pm
OK. The first thing to confirm is that you get two way traffic using the USB cable - no bluetooth involved.  If you get two-way comms with just the USB cable, the clearly there is nothing wrong with Arduino, or your code. The reason why I said "not quite" is to get the LEDs out of the game.

If you then get only only one-way traffic with bluetooth and

Quote
checked the physical wiring more times than I can count to make sure I'm hooking the correct pins on the HS-06 up to pins 0 and 1 on the Arduino.

then you might conclude there is a power supply problem, so now is the time when I don't want to hear that you carefully pulled the USB cable out and connected a 9v battery instead. If that is the case, I have no idea why it would work in one direction and not the other, but I would look to a better power source, even if it's only a 1A USB charger.

You might check the solder connections on the bluetooth's header. Somebody had a bridge between pins, but I can't remember if it caused your problem.

You are correct in that you cannot use Bluetooth and USB serial monitor on a PC at the same time, but you can have serial monitor on PC and Bluetooth on Android!
25  Using Arduino / Project Guidance / Re: Bluetooth module HC-06 on: August 09, 2014, 10:30:46 am
You need to be a lot more forthcoming about what you are doing, exactly what HC-06 device you are using, and post the code, using the hash icon.

I bought a bluetooth module HC-06. I connect Vcc to 3.3v,

This is OK if, and only if, you are using the bare HC-06 module

Quote
tx to rx and rx to tx.

Yes, hardware serial D0,D1

Quote
in some tutorial on youtube someone uses two resistors
Good idea for Arduino Tx

Quote
then I change the serial port from 24 (the usb one) to 35 (the buetooth one). but the in the serial monitor nothing is printed. what is wrong?

This is unintelligible but it may be that the only thing wrong is that you are trying to use the serial monitor as a terminal. Make sure the USB cable is disconnected and use a proper terminal programme like RealTerm through a properly defined COM port.

You might find the following background notes useful

http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino
26  Using Arduino / Networking, Protocols, and Devices / Re: Question About Debugging a Serial RX Issue on: August 09, 2014, 07:08:53 am
I've trimmed down the code to the absolute simplest test I could come up with:

Not quite.

These notes might be useful
http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2BT.pdf
http://homepages.ihug.com.au/~npyner/Arduino/BT_2_WAY.ino

Note that it is OK to have the USB connected to PC while  using Bluetooth with Android. Check the popwer connections
27  Topics / Home Automation and Networked Objects / Re: arduino android application on: August 09, 2014, 06:58:48 am
No. I understand you need a USB host shield, and that presupposes that the Android device is capable of the appropriate communication through USB.  I use bluetooth all the time but I don't know if my phone can do that, and it seems a pointless exercise anyway.
28  Topics / Home Automation and Networked Objects / Re: arduino android application on: August 08, 2014, 10:43:43 am
What is the easiest way to monitor the uno through the android ??

HC-05 bluetooth - $7- is probably the simplest. You send the data in exactly the same way you would send it to the serial monitor. Use BlueTerm on Android
29  Using Arduino / Project Guidance / Re: Can i put a 9V battery on VIN pin? on: August 07, 2014, 11:02:16 pm
   So are you saying that there is a risk of burning the arduino board or something?   

No risk so long as you are sensible about the connection, and nothing wrong with using it either.  Kind for kind,  the grunt of a battery is more or less reflected by its volume, so 6xAAs trumps a 9v and 6xDs puts you on a (short) road to glory.
30  Using Arduino / Project Guidance / Re: Can i put a 9V battery on VIN pin? on: August 07, 2014, 06:38:32 pm
Yes, but read reply #1 again.
I guess a 9v battery is useful for confirming that another power source is causing you problems, and using the VIN pin is an appropriate measure.
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