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4921  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Sending Video to PC via Xbee? on: May 08, 2010, 12:49:22 am
As noted before, you are unlikely to get any form of real video going the route you are wanting to take, but to get you started, this camera, and its breakout board, could be a starting point:

Someone has already gotten it working, and as you will be able to tell from the above links, it isn't expensive, and there is/was a pretty active users forum for the camera, discussing how to interface to it and use it (likely there is a port or some code for the arduino).

That would take care of the camera portion, but at 640x480 resolution, you won't have enough room on the Arduino itself to store the image.

What you could do (perhaps) is stream the data directly to your PC as fast as Xbee will allow, and store it there, or use an SD card adapter/shield and store it there, then stream the image data to your PC as needed. You could also potentially process each image in "chunks" of data, as well as possibly scale or crop the input data to a particular size/area to allow a higher "frame rate".

Hope this helps...

4922  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: What is Arduino? on: May 04, 2010, 01:09:12 pm
Mike, I think that thing needs its own spot in the Exhibition forum!


The prblem with being old is that people are always inventing names for stuff you did years ago before they had names.

Yeah, I'm starting to experience that myself...

Separates data and programming in different spaces.

I guess I didn't make that too clear, but that is what I was trying to convey (poorly, as it were!). I also keep forgetting that the "Von Neumann" architecture is referenced to Princeton, so thanks for clarifying that as well.

I am probably going to have to take a copy of that pic for my "archives" - its just such a great homebrew example (btw, thanks for also posting about that coin detector and the linear array yesterday; that went into my archives for later possible reference - just have to find a similar array - I haven't looked to see if that TLS array still is made or not)...

4923  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: What is Arduino? on: May 04, 2010, 11:56:56 am
I believe he's referring to a Single Board Computer.

I believe you're correct.

I am also surprised at Grumpy_Mike, mowcius, and MikMo for -not- knowing this...


Though I guess we all have our areas of interest and knowledge; all's good...


Regarding SBC's, though - while I suppose one could define the Arduino as an SBC and the ATMega as the microcontroller, I am not completely certain the Arduino can be technically classed as a true SBC.

This may be a personal bias, but I tend to think of an SBC as a single PCB with a microprocessor (such as a 6809, Z-80, 68000, etc), plus additional peripheral chips (MMU, address decoders, RAM, EPROM, etc), to make a "Single Board Computer"; the KIM-1 of eons past was an SBC, today's PC/104 boards are SBCs, the BeagleBoard is an SBC.

I also think of SBCs as being more general purpose, and generally having less dependence on the Harvard architecture for memory usage (I realize that modern CPUs all use a variant of HA internally, but for the most part this goes unnoticed by most programmers - whereas on many microcontrollers, like the ATMega, where HA is -very- apparent and noticed by the specific segmentation of memory into "program code", "data", "ram", etc).

Really, it doesn't make sense to ask if the Arduino can be made into an SBC; as a microcontroller technically -is- an SBC, shrunk down to a single IC. That doesn't mean it wouldn't be possible; I can envision setting up the data ports on a ATMega to act as address lines, r/w and control lines, and data lines, connected as a bus to other peripheral chips (ram, rom, eprom, etc) - but it doesn't make much sense to do it, especially since these functions can also be done using a fast serial bus (SPI or I2C). Plus, since the ATMega uses the Harvard architecture, you wouldn't gain anything for program running space, only extra data storage space.

Which brings up another point: Are there any Atmel processors that could be used and ported to the Arduino platform that -do- support external memory for expansion of program -and- data storage space? Are there any that support code execution from an external eeprom or other memory device? It would certainly be nice to have an 8-bit microcontroller with the ability to expand its memory up to the limits of its address space (without it being "pre-defined"); also, if such a thing were possible, you could do a segmented/paged address scheme to expand beyond that limit (boo, hiss, I know it is a hated thing, but you gotta admit its a slick hack - especially when it was common back in the day, when RAM was DIP-based and expensive!).

4924  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Looking for cheap, non-conductive thermal adhesive on: May 04, 2010, 09:57:00 pm
Something you might try (that may or may not work?) would be to use a shaft key (with a rounded top) of the right size:

Arctic silver the shaft key to the regulator, and the key to the inside of the tube...
4925  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: L298V? on: May 04, 2010, 09:50:18 pm
Well, while that wasn't a datasheet, it had enough specs that comparing it to the ST datasheet for the 298N, it seems pretty much the same.

Thank you.

4926  Forum 2005-2010 (read only) / Frequently-Asked Questions / L298V? on: May 04, 2010, 12:25:24 am
Hello, all.

This past weekend I visited (again!) my favorite electronics junkyard here in Phoenix, Apache Reclamation and Electronics. While I was there, I picked up a few parts after rummaging thru several parts bins. I was able to find spec sheets for the MOSFETs I picked up (10 pcs of MTP3055E - unfortunately not logic level - but they were only 75 cents each, so meh - maybe I can use them somewhere). However, I am having trouble with another part, a particular version of the L298 h-bridge driver.

All I can seem to find online for a spec sheet are the same-ole' ST L298 spec sheet PDF, which talks about the L298N, L298HN, and L298P. I have 5 pcs of L298N (yay), and 5 pcs of L298V (?).

I can't locate a spec sheet for the L298V specifically, and the ST spec sheet says nothing about it; both look the same otherwise (multiwatt 15 vertical package with the staggered leads). Is there any difference between the two I should know about, or can I treat it just like an L298N?

Thanks, guys!

4927  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Is My Project Possible? on: April 26, 2010, 11:18:14 am
The only thing is, would I be able to easily give it a different soundset?

Have you ever programmed a computer to make sounds (what I mean here is generating a waveform and playing it - not using a library or something, but bit-banging a speaker, or even a sound card directly)? If you haven't, then you will have to learn that; fortunately, it is fairly easy if you have the coding chops.

As far as the hardware is concerned, yes, it won't be easy to hook up an Arduino to a keyboard - but you have to start small, just like you did with programming (or at least, I hope you did). Buy an Arduino, a switch, a few other parts (piezo buzzer, resistors, etc) and a breadboard, and start playing with the examples. There are plenty out there on how to use the Tone library, for instance, to make sound and play music. There are plenty of other tutorials out there on how to make other sounds with the Arduino as well. What you won't find much of is how to shape a sound with an ASDR (attack-sustain-decay-release) envelope, which is the heart of FM sound synthesis (allowing a simple sine or triangle wave to become a piano or flute tone, respectively; or noise to become a drum) - but there is plenty of other information about this in PC sound generation (look into old-school demo sound coding using an R2R network on the PC parallel port - you'll find a ton).

Take it slow, one step at a time. Get sound to play; learn how to use a switch to control a program, then combine the two - and there, you have one "key" controlling a single "sound". From there, it is just a matter of expansion...

This won't be an easy or quick project, but it could be one that will teach you a ton of things about hardware interfacing, sound synthesis, control, etc - that you don't get from other projects. Nothing worthwhile is quick or easy - nothing.

4928  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Is My Project Possible? on: April 25, 2010, 04:55:57 pm
If I were you, I would definitely -not- go the route of wiring up a keyboard; depending on how well you want it to work (and how you want it to react), it could eat up your entire budge. Instead, I would visit a local thrift/second-hand store, and see if I could find an old cheapo synthesizer. Depending on the item and where you find it, and how well it still works, you shouldn't have to spend more than $20.00 (unless it is a larger-size synth).

Make sure whatever one you find -doesn't- have MIDI IN/OUT - why? Because those keyboards, if they work, should be reserved for the budding (or poor) MIDI artists out there. Also, research the heck out of whatever cheapo synth you buy; there are a few out there that are considered "classic" (especially among bender crowd - but also among collectors), and if you tear one of those up, you will only end up crying when you find it is worth waaaay more than what you paid for it.

You might pick up a couple to expand the available octave range if the ones you find are of the smaller variety (and if you can find two or more the same size; or go tiered?); what you won't find on these keyboards, though, is advanced features like velocity control and other such things you find on better synthesizers (but that's OK - you couldn't build such things into a playable home-brew keyboard anyway for $100.00).

Once you have your cheapo-synth, and you know it isn't anything anyone cares about (or maybe you don't care; just realize, though that such an act of "restruction" would be considered by some akin to taking a crayon to an original copy of the Magna Carta), then you at least have a pre-made keyboard, plus a lot of other parts you could use in your custom synthesizer (including a sound chip and amplifier, if you care to interface to them!).

Oh - did I mention "Circuit Bending"? You may want to look into that scene; while in some cases they have done the above "sacrilege" against certain keyboards and electronics (especially speak-n-spells; then again, there were a ton made, so whatever), some of their techniques might be of interest to you.

I generally agree with Grumpy_Mike, and he has educated me on some things (and maybe he will here, too) - but I don't think sound generation is outside the scope of an Arduino. I have nothing to back this up (its on my "someday" list), but I think the Arduino would be more than capable of generating 8-bit single channel FM, or possibly 12-bit dual-channel FM (6 bits per channel), using simplified wave tables and ASDR envelopes (DDS - direct digital synthesis). Depending on how well you write the code, you might be able to have multiple voices mixed on the output. Output of the sound could happen either via a DAC (a simple resistor ladder DAC would be fine); you could also possibly output the sound using PWM and filtering.

What it couldn't do, though, is all of that plus keyboard scanning; I do think it could act as the synthesizer sound source, alone, though. Alternatively (and perhaps within your budget as well), you could interface with a sound chip like this one:

You might also find specs on-line for the sound chip in the original synthesizer; you have a number of options available ultimately.

Good luck with the project; take it in simple, easily digestible chunks and steps, and it should work out!

4929  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Driving a multiplex LCD on: April 29, 2010, 11:47:47 am
That is interesting - seems like there's an app note out there for everything if you are willing to look! Glad you were able to find that; were you successful?

4930  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Driving a multiplex LCD on: March 18, 2010, 04:33:41 pm
You're probably not going to have much luck interfacing with those LCDs unless you can find a spec sheet for them; if they don't have an integrated driver chipset (ie, the IC for the bike computer controls them), then you are either going to need to get such a driver IC or implement its functionality in software.

I don't know much about bare LCDs like you seem to be describing, other than that they require an AC signal at a certain frequency to activate the segments (DC will typically kill the segments); you might be able to generate this with the Arduino (maybe running a pin PWM with a negative DC offset?), but what voltage level you need is unknown (more than 5V? less? my guess would be less, possibly much less).

A way to figure out which segments are controlled by what might be to figure out with pin is ground, then ground other pins to it - if multiple segments are affected, then that is probably some kind of common pin, whereas if a single segment is affected, then that pin is for that segment, of course.

Sorry I couldn't be of more help...good luck!

4931  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Assembly or GCC? on: April 13, 2010, 09:19:52 pm
gcc is a compiler, not a language; avr-gcc is (IIRC) the compiler instance of gcc that is called by the Arduino IDE to compile the code (AVR C) into the binary that is uploaded to the Arduino board (via avrdude).

So, in effect, you already know the programming language, which is AVR C.

If you want a challenge, though, I would expect AVR assembler to be  one (from my experience with 80x86 assembler - though that has its own quirks, especially with memory handling in 16 bit mode). But if you are just wanting to get something done and not learn an entirely new language, stick with what you know (AVR C).

4932  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Can i connect two 16x4 lcd displays to arduino meg on: February 26, 2010, 05:11:01 pm
Awesome pic on that quad display, floresta - I love it!

 ;D ;D ;D
4933  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: salvaging a cd drive - what can i expect? on: April 26, 2010, 12:44:49 am
You'll typically find some gears and such (mainly for the cd tray opener), maybe a micro-switch or an optical interruptor (to tell when the tray is open/closed). There will be some form of short linear slide mechanisms (for the laser to ride on); the laser itself (provided you can figure out how to power it); the focus mechanism for the laser (generally a part of the whole laser system - it may be almost impossible to separate the two without damaging one or both). Depending on the drive and your need, the flat sheet metal that forms the outer case of the drive could be handy for things like custom brackets and such (if you have some common hand tools like nibblers, sheet metal snips, etc).
4934  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Chaining modules on: April 25, 2010, 04:08:18 pm
Let's think of a R/C vehicle: one arduino would be the brain, one for "the legs", one for the sensors? They could communicate via their I/O?

It really depends on what you are controlling and how fast (or how "realtime") you need to control it; for a simple wheeled R/C vehicle converted to a robot platform, your idea would probably be overkill - unless some of your sensors were a GPS module, and you needed to do real-time path planning/mapping coupled to IR/ultrasonic distance sensors, all while the vehicle was running around 60 mph...

Alternatively, you might have something like a 6-legged walker, and you need to do all of the above, but each leg also needs a bit of "smarts" on its own (for path planning, IK, etc) - then maybe a processor per leg would be needed, even though things might not be moving as quickly (and if they are - even more so!).

Generally, the best way to approach things is to first determine your goals, research what is needed to reach those goals, then size the system accordingly; in a system I am (slowly) building, I am only using an Arduino for basic control of motors, with servos being handled by Pololu MSSC; but on the backend I have a full PC with a fair amount of RAM and hard drive space for a future vision/LIDAR system (something which the Arduino couldn't do, at least not to the level I think will be needed).

For most systems, though, the simpler you make it, the better...

4935  Forum 2005-2010 (read only) / Frequently-Asked Questions / Re: Arduino Hardware Choices - Help Needed on: April 23, 2010, 04:16:10 pm
You might be able to get all of this done with the Duemilanove; in fact, I would start with it, and the rest of the components, mainly because most people use it over the Mega, there is a ton of code out there already (and a lot of people have done GPS interfaces; plenty of threads on these forums), and it is geared toward the newbie.

There is also another reason to try this, and that would be to, in the "final product", incorporate the LilyPad 328 into the design - you would have to figure out what to do with the GPS module and LCD, but in theory you could make a "stack" with the LilyPad 328, GPS, LCD, and your buttons, and put it inside a slick round case, and end up with something real similar to that puck (especially if you can find a small LCD; maybe a Nokia cellphone serial GLCD could work?).

But first, prototype it out with the Duemilanove, then move it to the LilyPad once you are comfortable that everything is working; pick your other components (GPS and LCD, mainly) to fit in the footprint of the LilyPad. Sparkfun has plenty of options, there; if I was doing this I would go for these parts:

Arduino Duemilanove:


FTDI breakout for LilyPad:

GPS Module:

MicroSD breakout:


Plus your sundry buttons and such.

When you get to the LilyPad final, you will also want these, likely:

LilyPad LiPower Board:

LiPoly Battery:

Plus whatever case you want to put it in...

The only part that you may want to put more research into would probably be the GPS unit; I picked one of the small ones (I think it is smaller than the LilyPad) - but I don't know the particular merits/downsides to each GPS module; it may or may not be best for your application.

Hope this helps in some manner...


[edit]Another note: Some of these parts are 3.3V, some are 5V; you may need level shifters and such to get things working - which could make the "compact" bit more difficult; I am not sure how you could get around this (without having to create your own custom PCB layout)...[/edit]
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