Show Posts
Pages: [1] 2 3 ... 451
1  Using Arduino / General Electronics / Re: What's this peice called? on: Today at 03:17:07 am
Adafruit is an evangelist of open source, and AFAIK all their boards have online schematics and pcb layout files.
In this case:
It's a 10uF 0805 ceramic cap (C7) on the 3.3V regulator output.
2  Using Arduino / Microcontrollers / Re: Standard Fuse Settings for 16Mhz ATMega328p on: Today at 02:21:39 am
If you've really set HFUSE to 0xE1, then you've disabled SPI programming, and indeed "bricked" your chip to the extent that you'll need a HV Parallel programmer to un-brick it.  (However, you're not supposed to be able to disable SPI *using* SPI, so this shouldn't be the case.)  Most likely, you've just programmed the crystal oscillator to a mode that doesn't work with the actual crystal you have installed, and you can fix it by injecting a clock "manually."
3  Using Arduino / Programming Questions / Re: Free Flash memory remaining? on: July 23, 2014, 03:10:38 am
You can certainly READ the flash memory from within a sketch.  So you could theoretically start from the known end of flash and scan pages until you find one that isn't full of 0xFF (pages full of 0xFF at the end of flash are presumably "unused.")

I still don't see how you expect to "push to flash", though.

You could look at serial flash/eeprom, which is physically easy to connect to the AVR (slightly easier than an SD card), and MUCH easier to write to than an SD card (no filesystem; just a straight memory array.)  Not anywhere near as large as an SD card, but you should be able to get about 1MB for reasonable cost (actually, ridiculously cheap...): is one example
4  Development / Suggestions for the Arduino Project / Re: Does Arduino have a future? on: July 22, 2014, 05:02:32 pm
It's intended for artists, designers, hobbyists and anyone interested in creating interactive objects or environments.
For this market, a product has to be "right-sized."  The Duemilanove with m168 was about perfect for a lot of things; the m328 versions added additional memory space "for free", so that was OK too.

The next question is "what else will people pay for?"  Arduino MEGA?  Networking?  Depressingly overpriced in the Arduino arena, IMO.  But a lot of those "art" and "design" projects seem to have a weird budget model (compared to "hobbyist" or "commercial" anyway.)

After that, perhaps "how much can be improved at the same price points?"  I haven't been inclined to do much with MEGA or Due, but I have some Teensy3 modules, ChipKits, and m1284 boards.  They're swell, I think.  Arduino Zero might have potential.

Things like the RPi, BeagleBone, ST, NXP, and TI ARM boards have always bothered me.  As a hobbyist, they're OK.  But my theoretical "goal" is small scale production of custom electronics (say, 100 to 1000 boards?)  With a mega328-sized design, I can easily plunk down the "meat" of an arduino on my own board design, assemble them by hand, and be done.  For the small pitch parts on the "more powerful" designs, I don't think that there is any way I can duplicate the cost of the sold boards with my own board, by the time I do the 4+ layer PCB and contract assembly.  Maybe I shouldn't care, and using vendor-subsidized
modules with questionable product lifetimes and licensing issues is the way to go. :-(

I watched with some amusement and horror as linux system administration issues on RPi and BB replace the programming and electronics issues people have with Arduino/etc. :-(

I'd like to see an OS that is closer to Bare Metal for BB and RPi.  Or an OS for  Teensy/NXP/ST/TI that is better than the current bare metal, without sacrificing the "ease of use" of the Arduino libraries.  But I don't think that either one exists yet. :-(
5  Using Arduino / General Electronics / Re: Recommendations for Waterproofing, clear dippable potting compound on: July 22, 2014, 03:50:46 am
Aside from the "professional electronics products" from the likes of
you might check out or ask at smooth-on, who are generally pretty maker-friendly and have explored a lot of applications for the casting products they sell.  Eg:
6  General Category / General Discussion / Re: What is the difference between Arduino IDE version 1.0.5 and beta 1.5.7? on: July 22, 2014, 03:27:47 am
Mostly, 1.5.x supports more boards; specifically, the non-AVR boards like the Due.
In fact, it implements new infrastructure that allows any number of platforms to be supported or added to the IDE.
7  Development / Suggestions for the Arduino Project / Re: Bug in serial uploading on: July 22, 2014, 02:56:38 am
I don't see how this is an Arduino problem.  Complain to the author of the ch340 USB driver.
 "tty.wch ch341 usb=> RS232 1d120" is an amazingly bad choice of name for a unix-like file!
8  General Category / General Discussion / Re: Good career options for arduino enthusiasts, and similar tech minded people? on: July 21, 2014, 04:07:52 pm
Yeah: artist, electronics technician, entrepreneur, "consultant."
Most of these are pretty "iffy" (check out the average yearly income for an "artist"!); for a good career, you should go after a degree.  The ability to build working Arduino projects will put you quite a bit beyond the CS or EE majors that did nothing beyond their classes and assignments.  But the degree will put you far beyond the hobbyist in areas like physics, math, "theory", and other areas that employers think might be important someday.  And they can be: you may never need to solve a symbolic differential equation, but I can't imagine doing much with PID control algorithms without having done calculus.  Or that blank look some people get when you explain that graphics transformations can be done with matrix multiplies.  For those entrepreneur and consultant careers, you ought to have some business classes (perhaps a LOT of business classes.  Depressing, but true.)

There's also a "job security" issue: you may find a perfect job hacking arduinos and such, but if you lose that job, finding new opportunities without a degree may be difficult.  I know people with 30+ years of experience who were laid off and now having troubles getting their resume past the 'first tier' of screeners at potential employers. :-(

9  Development / Other Hardware Development / Re: Help programming atmega328 chip on: July 21, 2014, 02:08:28 am
There are two bootloaders commonly found on m328 chips, and you need to match your "board" setting to the bootloader, rather than to the hardware of your board.  Try "Uno" for the optiboot bootloader, and "Duemilanove w 328" for the older atmegaboot bootloader...
10  Using Arduino / Programming Questions / Re: Free Flash memory remaining? on: July 21, 2014, 01:31:10 am
The linker produces a symbol "_etext" just beyond the last flash address used.  So this should be the first free flash location when your sketch starts.  As you write flash, you'd have to keep track of how much you've written on your own.  (though I still suspect that things are not going to work the way you expect.  The AVR is NOT one of those architectures where it is "easy" to use the flash program memory as non-volatile storage.  You might look at "amforth" as an example of a program that does rewrite flash on the fly...)

extern const short PROGMEM _etext;

void loop()
  fp("\nCompiled for " __CPUNAME "\n");
  fp("Etext = 0x");
  Serial.println((unsigned long)&_etext, HEX);
Compiled for ATmega328P
Etext = 0x1DC2
11  Using Arduino / Programming Questions / Re: Arduino uno R3 timer 1 in CTC mode pulses once after reset, will not re-trigger on: July 21, 2014, 01:10:30 am
I don't actually see anything wrong.  But I'm not an expert manipulating the AVR timers...

I'd be a lot happier if you separated the timer initialization (modes/etc) from the code that you expect to repeat.  "Restoring to initial state" seems like a poor idea.  (Hmm.  Are you restoring to the AVR "reset" state, or to the state that the arduino init() code sets the timers to?)

How about some symbolic constants for those timer register bits?

It doesn't seem like a good idea to me, to reset the port pins to inputs immediately after the OCC matches both occur.  don't you want the pulses to be "active" ?

You want something like this, right?
   while (1) {
     start_timer(); // start both pulses.
     while (!(doneA && doneB))
        ;  // spin, waiting for both pulses to complete.
   }  // repeat the pulses 

Why don't you start by writing it just like that?  if it's too slow AFTER it is working, you can work on optimizing it by glopping all the code together.  (but the compiler will probably do that for you anyway...)

In general, I think we don't emphasize breaking code into modular pieces enough in these forums...  :-(

12  Using Arduino / Microcontrollers / Re: The Armalite, SAM3 32-bit "Arduino-Due-compatible" design on: July 21, 2014, 12:16:40 am
Teensy 3.1?
13  Using Arduino / Microcontrollers / Re: I want to be sure before going to the next step..... on: July 20, 2014, 09:00:00 pm
I want to be sure this board will "work"
That's a problem with the cheap eBay variations: being "sure" is pretty tough.  Frequently you have some design that has "propagated" through several layers of designer/manufacturer, and a vendor that is clueless about arduino (or ANY electronics) (and is also selling toys, clothing, etc.)  You have to buy them and try them out, and hope that your source doesn't change the board they provide sometime mid-way through the number of boards you were planning to buy from them.

I've heard that the ch340 USB chip used in this version does not have a MacOS driver, for example.  (but spycatcher's file include one, so perhaps that it obsolete info.)  ( )
14  Using Arduino / Microcontrollers / Re: Reburn STAMP BASIC on: July 18, 2014, 01:15:14 am
Note that while this board would work pretty well as a general purpose prototype board, it's designed for using the Propeller chip, which isn't even a Basic Stamp...
15  Using Arduino / Programming Questions / Re: Free Flash memory remaining? on: July 18, 2014, 12:50:06 am
I'm adding and holding data as needed in FLASH thanks to PROGMEM.
You can't "add" to PROGMEM data in flash at runtime; PROGMEM is read-only data.  you use pgm_read_byte() or similar to read the data from PROGMEM variables, and there is no equivalent for writing data.  (The "bootloader section" of the AVR can write to flash, but that doesn't use PROGMEM and requires manual operations considerably more complex than dereferencing pointers.  And Arduino sketches are not in the bootloader section, so they can't do it anyway.)

Now, the flash memory space goes from 0 to 32k, and part of that overlaps the RAM address space (which goes from 0x100 to 2k+0x100), so if you carelessly dereference PROGMEM pointers, you'll end up reading/writing to RAM instead, which MIGHT look like it's working as long as the addresses you write doesn't overwrite data important for something else...)
Pages: [1] 2 3 ... 451