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31  Using Arduino / Microcontrollers / Re: New optiboot; beta testers welcome... on: August 14, 2014, 03:14:52 am
Does this mean that the maniacbug optiboot for the mega1284 will fail for programs > 64K?
No, because it's a WORD count rather than a byte count.  The mega1284 (and the mega1280 as well) only have 64k words, so the optiboot loads (and works) fine using ArduinoISP.
32  Using Arduino / Microcontrollers / Re: Standard Fuse Settings for 16Mhz ATMega328p on: August 14, 2014, 03:11:35 am
I tried it out and now both arduino's are running blink at the same wrong clock speed
Even after you disconnect them from one another?  It turns out that the LED pin IS one of the signals used to connect the two arduinos, so both LEDs will flash when the non-broken one does the flashing...
33  Using Arduino / Microcontrollers / Re: New optiboot; beta testers welcome... on: August 14, 2014, 01:07:44 am
have you verified that the "Adaboot no wait mod" actually still works?
Hmm.  I works here on assorted atmega8, atmega168, and mega328p boards.  But not on my Uno SMD (r2)...
Your patch (actually, a variation of it) does seem to help...

( )
34  Using Arduino / General Electronics / Re: Best PCB degign for beginner. on: August 14, 2014, 12:42:35 am
I think its what you are all used to.
A lot of people seem to expect a PCB design package to be like a drawing program, but it really NEEDS to do a lot more than that,  and consequently is usually significantly different...  (One difference is that you really want all the bits and pieces to have NAMES.  Pin names, signal names, etc...)
35  Using Arduino / Microcontrollers / Re: Standard Fuse Settings for 16Mhz ATMega328p on: August 13, 2014, 10:36:41 pm
I think that the closest you can get to HV parallel programming with an Arduino is this 5V "rescue" shield:

The clock injection you can get with the adafruit-modified Arduino ISP is NOT parallel programming, and will not fix some "bricked" AVRs (although the clock injection with serial programming DOES fix the most common bricking scenarios.) (And ArduinoISP does not support HV parallel programming at all.)

36  Using Arduino / Microcontrollers / Re: ATmega168 Programming: Which board to use? on: August 13, 2014, 10:29:43 pm
avrdude: Device signature = 0x1e940b
avrdude: Expected signature for ATMEGA168 is 1E 94 06
The ATmega168/ATmega168A and ATmega168P/ATmega168PA have different chip signatures, just like the ATmega328 vs ATmega328p problems that have been pretty well covered in these forums.

When trying to change, I got this error
'MCU 'atmega168' supported for assembler only'
When trying to change WHAT, exactly, and to what, and what is giving you that error message?
And what software (and what device programmer) do you have installed, anyway?
It's been a long time since atmega168 was only supported by assembler, or since "Make" was not included in AVR development packages...  (The choices are essentially:  Atmel Toolset, Atmel Studio (which includes the toolset),  WinAVR, and Arduino (which includes WinAVR.))

37  Using Arduino / Programming Questions / Re: ENC28J60 vs WIZnet w5100 simple server code difference ? on: August 13, 2014, 06:39:17 pm
I want it to be a server using mac only to start
That's not what your current wiznet code does.  Behind your "server.begin" is ARP, IP, TCP, and other stuff that is hidden from you, but nevertheless THERE.  To get similar code to work on the ENC28J60-based network, you have to have a library that implements all of those protocols (they are implemented in hardware on the WizNet chip.)

(actually, I don't think the Wiznet code will work as shown, because it doesn't specify or acquire an IP address.  In that sense (ie "it doesn't do anything"), it should be easy to duplicate with the Microchip ethernet controller. :-) )
38  Using Arduino / Microcontrollers / Re: ATMega8a Bootloader on: August 13, 2014, 06:26:56 pm
This is because different atmega8 bootloaders work at different baud speeds.  ... Even worse, if the bootloader is not the same a change in the fuse settings and/or available memory may need to be updated for correct operation.
To be fair, this is true of the m328 as well, but there are fewer bootloaders "in common use", and all of them are at least some-what supported by someone.  Mega8 bootloaders are more of a "find one you like and make it work" thing.
39  Using Arduino / Programming Questions / Re: Arduino does not recognize new line from Matlab fprintf on: August 13, 2014, 03:50:32 pm
He's suggesting a delay.
In general, if you're expecting to read certain characters, you should replace calls with a function that waits for the traffic:
int getcwait() {
   while (Serial.available() == 0)
     { /* spin */ }
40  Community / Bar Sport / Re: How do they weigh.... on: August 13, 2014, 03:41:22 pm
2750 psi? That's good for 30 minutes?
That was the (old-ish) standard steel tank - 72 ft^2 at 2750psi, about 30 minutes at 30 feet depth (close to an hour at the surface.)
Modern tanks are bigger and higher pressure.  80ft^2 at 3000psi typical for Aluminum, and I see some composite tanks at 4300psi. (hmm.  All are negatively buoyant when full and float when empty.)  (The SCUBA "big idea" is that you breath gas an ambient pressure.   And then exhale as bubbles.  1 Atm additional pressure for every 10m depth, approximately.  So at 30m depth, you use up your air three times faster than at the surface.)

You would have to spend the hours breathing helium+oxygen+CO2 just to get the nitrogen out of your blood before helium in your tank would do you any good.
Huh?  Nitrogen has several problems:
1) At higher pressures, nitrogen starts behaving like an anesthetic.  Individual tolerance supposedly varies, but getting "drunk" at 150ft down is "not good."
2) Nitrogen dissolves in your blood.  At higher pressures, more dissolves, and then it un-dissolves when the pressure is reduced again, resulting in the infamous "bends."  The longer you stay in high-pressure situations, the more nitrogen dissolves in your blood, and you have to make "decompression" stops where you wait at various (shallower) depths for the nitrogen to exit via your lungs instead of as bubbles in your circulatory system.
Breathing Helium/oxygen mixtures is considered "Technical diving", which is one step past "Sport diving."  I believe it's done mostly to avoid the narcosis issues; my training didn't include any helium decompression info (In the 70s when I took my first class, Helium wasn't available to amateurs.  My second class in the early 90s, it was explicitly "not included" in the sport diver training); but I recall reading that helium mixes don't entirely eliminate bends-like problems.

I've never heard of a need to purge atmospheric pressure nitrogen from your system...  (although, after diving, even without needing decompression, you are supposed to avoid low-pressure situations (like airplane flights) for quite some time...)
41  Using Arduino / Programming Questions / Re: Arduino does not recognize new line from Matlab fprintf on: August 13, 2014, 01:55:21 am
I would expect "parseint" to "eat" the character that terminates the number.  So if you send "1 2 3\n", parsing the third number will read the \n as well, leaving the next to return the next character AFTER that (or -1 if nothing is there.)
(This doesn't explain why it seems to work when using the serial monitor.)

If this is correct, you can probably fix it by having the matlab code send an explicit terminator before the newline ("1 2 3 \n" - note the extra space.)
42  Using Arduino / Programming Questions / Re: Compiler math bug 2*60*1000 = -11072 on: August 12, 2014, 08:42:26 pm
The compiler assumes 16 bit for the #define expressions - that is different from all other compilers I am using.
Yes, this is likely.  Most modern C compilers run on 32bit CPUs and make an "int" be 32bits long.
Since the AVR is an 8bit CPU, it only uses 16bit "ints" (which are about twice as fast and twice as small (code-size) as 32bit ints would be.  This is allowable, and is NOT a bug.  But it can be surprising.  (The original PDP/11 "C" compiler had 16bit ints too.)
43  Using Arduino / Microcontrollers / Re: Arduino Mega2560 as ISP to program another Arduino Mega2560 on: August 12, 2014, 08:34:43 pm
It is equally a bug that the "bootrst" fuse is left programmed (0) on a  m328 when you do "upload using programmer."  It only works if the sketch is short enough not to overlap where the bootloader WOULD be...

This was apparently reported a long time ago, but never understood well enough to fix.  I've added a comment to the bug.
44  Using Arduino / Microcontrollers / Re: Arduino Mega2560 as ISP to program another Arduino Mega2560 on: August 12, 2014, 05:15:26 am
It was uploading sketches via ISP that wasn't working?
It's possible that that doesn't work on 2560, but does work on 328, because the program counter wrap-around happens differently on a chip with more than 64kwords of flash.  On a 328, if you start in the "bootloader section" at 0x3F00 (where there isn't any actual code), it will execute relatively useless but unharmful instructions till it gets to 0x3FFF, and then wrap around to location 0x0, where your sketch actually begins.  On a 2560, if the bootloader section starts at 0x1F000 and muddles along to 0x1FFFF, I'm not sure whether it will wrap to 0x0 (your sketch), or to 0x10000 (middle of nowhere, where it will eventually wrap again.)

I can't find this clarified in the documentation.  Not that you need a "long" jump/call or to use EIND to change the high bit during normal program execution.
45  Community / Bar Sport / Re: Holy Crap Lightning Strike Damage! on: August 12, 2014, 12:33:12 am
what was more surprising was that it blew up my telephone and (dial-up) modem. My telephone service cable runs underground until it enters my house!
conduction of lightning strike through the ground is apparently one of the common ways to get hurt...
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