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1  Using Arduino / Networking, Protocols, and Devices / Re: GPRS Data usage on: November 24, 2013, 03:02:28 pm
Also, If no one here has any idea of this, can someone suggest somewhere that I might be able to get an answer to this without having to simply spend money and investigate for myself?  Don't really want to do that if I can avoid it hehe.
2  Using Arduino / Networking, Protocols, and Devices / GPRS Data usage on: November 23, 2013, 06:22:30 pm
Hmm, this might not be the best forum for this question, but it seemed like the closest.

I'm hoping someone might have experience with using an arduino and GPRS in order to help me out with this.  I'm currently working on a project that is going to have cellular communication in it.  I'm trying to decide if it would be better to go with SMS based communication for getting messages to a web service, or GPRS data.

Looking at, I can get 5 MB monthly data or 100 SMS messages for about the same cost (5 MB monthly is 10 dollars more per year, which is the packages I'm looking at).  Now 100 SMS messages is potentially ~15.6 MBs of data, however, each message sent is at minimum 160 Bytes, so smaller amounts of data sent will waste some bytes.  So by that fact it makes the 5 MB monthly data look more attractive, because that is enough data to send 512 - 10 byte messages.  However that brings me to my question.

I'm sure GPRS connections have some overhead data usage that I'm not taking into consideration.  And I'm wondering how much data usage that overhead is.  I imagine the initial connection talk with the web server is going to use some data, as well as the web server response.  If we assume the page that loads on this webservice only contains 1 byte (either a 1 or 0 or something like that to indicate success / failure), how much overhead is each message of 10 bytes going to have?  Will I still come out ahead in the number of messages I can send on a data plan, or will the overhead make it as limited as SMS?

One huge advantage though to SMS still is the fact that I would be able to send SMS messages to the device, where as with GPRS only, due tot he nature of the celluar network, the device would have to query a webserver to check for messages every so often which means more wasted data.  I just don't think 100 SMS will be enough in the long run for my project, and the next plan up is 500 SMS and costs twice as much =/

Thanks for any advice!
3  Using Arduino / General Electronics / Re: What are these wire headers called? on: November 22, 2013, 09:45:24 pm
Awesome, thanks!

Gonna go order a bunch of these now smiley
4  Using Arduino / General Electronics / What are these wire headers called? on: November 22, 2013, 07:03:02 pm
I haven't been able to find somewhere to buy wire headers like these.  I'm sure they can be bought, I just don't know what they are called and haven't seen them for sale somewhere.

Can someone help me out?  (Not the ones plugged into the breadboard, the ones attached to the end of the wires that allows them to plug into the header on the breadboard.)

5  Development / Other Software Development / Re: Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches on: November 20, 2013, 09:49:44 pm
Hey, sorry if this has been asked somewhere above, but with 24 pages I couldn't find anything and trying to search didn't have much luck.  In the first post it says

version 1.0.10 is now tested on openSUSE
Latest version are tested and running on MAC
Added serial monitor

I'm having trouble finding the serial monitor.  I've looked through all the menus and at all the buttons but don't see anything labeled as or that looks like a serial monitor.

I'm looking for an alternative IDE because for some reason the Arduino IDE will simply not work in WIndows 8 for me.  After a few minutes the GUI stops refreshing itself.  Near as I can tell, it's updating, simply not refreshing.  I can move the window around and when I change the window state in order to force a window redraw operation it updates with anything I've done while it wasn't updating.  Highly annoying and happens with both 1.0.5 and 1.5.4 r2.  I've always liked eclipse in the past for side projects so thought this might be a nice plugin to try out.
6  Development / Other Software Development / Arduino IDE and Windows 8 problems on: November 18, 2013, 11:40:57 pm
I'm having some weird problems with the Arduino IDE on a fresh install of Windows 8.  The gui just randomly stops updating.  The window itself still responds (minimize, maximize, close), but the Menus won't respond, can't scroll text or type in text, and the buttons don't highlight or seem to work when I mouse over them.

I've tried both 1.0.5 and the beta 1.5.4-r2, both installed and just running from a zip.  All ways has the same problems.

Anyone else experience this or similar problems and have any work around for them?
7  Using Arduino / Audio / Re: HDMI Audio decoding on: November 08, 2013, 10:22:38 am
Just a little more information that I just uncovered.

It looks like a chip like this one: can split the video and audio signals on the HDMI.  But it maintains a digital format.  After that another chip is needed to process the audio (I assume this is where it gets separated into individual channels but not 100% certain), and finally it goes through a chip to get decoded.  The decoding is where the hang up is.  I haven't found anything for sure but it seems you are supposed to have a license to decode HDMI audio.  And most of the chips I could find to do such were sold in bulk only.

So maybe this is something that is beyond a DIY project simply because of the licensing and supply requirements.  I read in one place that it was 15,000 dollars to purchase a license lol.  Unless someone has more information on a cheap alternative method for decoding the audio.  If that's the case I'll probably end buying something like that devices I linked on ebay and simply integrating it into my "unit".  Either that or perhaps I will consider switching to a Linux based Carputer system in order to use a USB soundcard that has the outputs I want already on it...  Lots of downsides to work around for that though, I'd lose Googles built into android voice recognition, google maps navigation, and a lot of other convenient for a  car pc android apps.  Or perhaps I'll just stay with my current audio set up and use a IoIo board or something to integrate with android and control the duplicated channel balances that way.
8  Using Arduino / Audio / Re: HDMI Audio decoding on: November 08, 2013, 09:44:40 am
Have you read the HDMI specs?
I can tell you that HDMI uses (up to) 3 channels of balanced serial data onto which things like video and multiple audio soundtracks, and other data is multiplexed at a very high data rate.

You must be a brave man to try and make a circuit to analyze the data stream, extract only the digital audio data then convert to analog, filter and playback.

My honest advice, buy a unit to do this.

It doesn't really seem to be that brave to me.  This technology has already been pioneered, I just need to know how they do it.  Buy pretty much any entertainment system with a good stereo receiver these days, and it does this.  I don't know what magical chip they have inside that does it, but it can be done.  And I've see units as cheap as 100 dollars that can do it, so it can't be an expensive component.

I figure if I built this device it would be great if I could just split the HDMI cable from my motherboard, send one to the LCD for video and one to this receiver unit for true 5.1 audio.
They do make HDMI splitters.   Does your receiver have HDMI, or is that what you're trying to build?

If your receiver doesn't have HDMI, I'd consider a 5.1 USB soundcard instead of HDMI.  I think that's the easiest, cheapest, best, way to do it.    With a USB soundcard, the right drivers, and the right applications, you should be able to handle any format as well as set-up bass management, etc.    If you get one that supports Dolby Pro Logic II, there are "soundfield" options for using the surround speakers with 2-channel stereo.  (I have my home theater system set-up for reverb in the rear channels when playing stereo music.)

If your receiver/head unit doesn't have HDMI but you really want to use it, I have some ideas.    

I don't have a receiver at all atm.  I'm wanting to do this for my carputer so I can take the HDMI out from my motherboard and split it into the individual channels to have connections for the speakers.  Instead of doing it the way I have it right now and taking a single stereo left / right output and just duplicating it to the rear speakers and amplifier for the subwoofer.  I mean doing that works, I would just prefer a cleaner output that can have better balance adjustment and a proper low frequency line to the subwoofers.  The motherboard I'm using does have SPDIF out too, but I think that is just as complex to split to individual channels as HDMI is.

I have seen small devices that can supposedly do what I want, but was hoping to build it myself so that I can make some customizations to it and add a 4x50w amplifier for my door speakers all in one unit.  For example this device on ebay claims to be able to do it:

Oh and the problem with a sound card is drivers.  Right now my carputer is running on Android 4.1, it will not recognize most sound cards.  But it does output 5.1 sound through the HDMI (I've tested that using my in home stereo receiver).  And my carputer is a headless unit (or rather the carputer is the head unit I guess hehe) currently.  The carputer does everything, I'm just using a secondary small amplifier for the door speakers.
9  Using Arduino / Audio / HDMI Audio decoding on: November 07, 2013, 11:33:12 am
Ok, so this isn't really an arduino specific question (although maybe it can be answered with arduino, I don't know!), but I figured all the expert tinkerers around here might be able to point me in the right direction.

I'm wondering how / what do I need to build a device capable of receiving an decoding HDMI audio in order to output it to speakers (just like a receiver does).

A little more detail about exactly what I want to achieve.  I have a carputer project that I've been working on off and on for the past few years.  Right now my solution to audio is rather basic and not what I'd like for it to be.  The LCD controller board that I'm using has an analog audio out for 2 channel output.  I just duplicate that to have front and rear channels (but I have no way to adjust their volumes individually), and feed off the rear to amp for pass filtering on the subwoofer.  This sounds ok, but I'd really like to beef it up.  What I would like to do is build a device that would serve as an amplifier for the door speakers, as well as have preamp outputs for the subwoofer amp.  I figure if I built this device it would be great if I could just split the HDMI cable from my motherboard, send one to the LCD for video and one to this receiver unit for true 5.1 audio.  I know it should be possible since living room recievers can do it, I just don't know what it would take to build one of my own.  And then I'd be able to adjust all the sound levels individually (both in software on the motherboard side as long as the output is actually 5.1, as well as the possibility of adjusting it in this device I would build).

I'm also hoping it would be possible to analyze the signal during processing and see if the source is 5.1 audio or if it's only 2 channel audio and if it's 2 channel audio duplicate the signal to the rear channels and preamp outs automatically so that I don't get a situation where something is only playing on the front speakers or such.  Would be even better if during that processing if it's duplicated like that to the preamp outs that I can do a software based filtering instead of relying on the amplifier to do it all, I think that could clean up the signal going to the amp resulting in better bass from the subs.

Thanks for any advice!
10  Development / Other Software Development / IDE for high DPI screens? on: November 07, 2013, 12:12:52 am
So, I got a new laptop a couple of weeks ago it's a Lenovo Yoga 2 Pro (3200 x 1800 13.3" screen).  Installed the arduino IDE on it today to realize that it apparently does not support DPI scaling.  So I have itty bitty tiny buttons and text.  Really, unusable.  Changing my screen resolution is not really the solution I'm looking for.  So I'm wondering if anyone has any suggestions?  Is there an alternative IDE that will work with this screen resolution, or another work around that I might be able to use?
11  Using Arduino / Displays / Re: Where to start on trying to connect arduino to a lcd? on: November 06, 2013, 06:41:12 pm
Ah, ok thanks for the feedback.

I've got a few x86 atom boards laying around, maybe I'll just try to do something with it on one of those.  They aren't THAT much bigger than a Pi hehe, I'm sure I can find something to do with them.
12  Using Arduino / Displays / Where to start on trying to connect arduino to a lcd? on: November 05, 2013, 09:49:44 pm
Ok, so I recently have gotten back into tinkering with my arduino stuff and am wanting to get back into displaying information on LCDs.  I ordered one of the Sainsmart 3.2" LCDs recently and am waiting on that to come in, but while digging through some of my old parts and such in the closet I came across a 7" LCD I bought a few years ago that was originally intended for my carputer project.

It's a VGA / S-Video display, but it's been so long since I bought it I can't really find any information about it.  The main video controller on the controller board though is a RTD2662 chip.  I found this pdf for that display controller:

It's also got a resistive touch on it, and there must be an audio chip on the controller somewhere as well because it has audio inputs and buttons  on the button board for volume up and down.

It's got this chip on there as well although I'm not sure of the purpose of it:

So do you guys think it would be possible to do something with this with an arduino?  I'm not sure what else I will do with a 7" vga lcd lol.  My carputer idea got upgraded to a capacitive touch screen so I don't need it for that project anymore, and all of my small system boards (cubieboard, raspberry pi, etc) are HDMI output.  The raspberry pi has an S-Video out, but I didn't have any luck getting that to work, not sure why really, haven't investigated it a whole lot.

I'm hoping maybe there are some libraries that I could modify, and hints somewhere that I could use to play around with this as an arduino interface.
13  Using Arduino / Displays / Re: Sainsmart 3.2" questions on: November 04, 2013, 02:55:25 pm
Awesome thanks for the info!

I also used my head a little and searched for some youtube videos for the screen and found some to show me the speeds and they are quite adequate for my projects smiley  A exponential amount better than the SeedStudio shield that I have.

So I just ordered two of these screens from Amazon smiley
14  Using Arduino / Displays / Sainsmart 3.2" questions on: November 04, 2013, 11:11:22 am
Hoping someone here might be able to help me with some questions I have on this display.  It's a pretty cheap display that has touch built in.  I haven't been able to mess around with my arduino hobby in a while, and last time I did all the displays available were expensive, and it was hard to find one that would work at a descent speed with an arduino.

So my questions concerning this display is, first would an arduino be able to handle the processing and displaying of graphics very well?  And if so, how fast is it at doing full screen changes (like say I had a full screen image and wanted to change to a different full screen image).  The screen that I have now and played with before was a smaller one from SeedStudio and it sucked bad for things like this.  It would take an arduino mega 20 to 40 seconds to redraw an entire screen because it had to update every single pixel and was very slow.  This screen says it has a controller built in, so I don't know if that would help with problems like this?

Second, another problem I had with the screen I was using before is that you could not turn the backlight off for a lower power mode (you had to cut power to the screen completely which added to slowness since you had to redraw whatever was on it when turning it back on).  Does anyone know if you can do that with this screen?  I consider it essential for any projects that are going to have a touch interface but not need to always be on.

Lastly, what kind of feedback does it send regarding touches?  Is it pressure sensitive at all?  How fast is the touch update (if I were writing controls to display on the screen for dragging this would be a big deal).

Alternatively, does anyone have any recommendations for a better 3" to 4" screen without getting to pricey.  I have multiple projects I'd like to have touch screens on, so don't want to have to spend 100 dollars per screen lol.  Although I do have one or two projects that could do with a bigger screen like a 5" or 7" and would of course be willing to spend a little more on those.  So on that same note, if anyone has any recommendations for a screen in that size range that could be driven with an arduino I'd like to hear those as well.

Thanks for any information anyone has.
15  Using Arduino / General Electronics / Re: Calculating amperage used by an inverter on: April 17, 2013, 06:55:40 pm
If my math is right, then surely there are some efficiency factors in the inverter that I need to take into account as well?
Yes it depends on the inverter. If you do not know then you have to measure it. The efficiency will normally be between 70 to 90 %

I'm assuming this means I am calculating it correctly at least?

What would I use to measure the efficiency?  I don't think my multi-meter could handle amperages past 10 amps, I'd have to double check it but pretty sure that is the size of the high amp side fuse.

What I'm thinking about using for my inverter is an APC UPS unit.  It's convenient in the fact that it should be fairly easy to rig it up to auto switch to grid power if the battery pack runs down.
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