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1  Using Arduino / Microcontrollers / Re: Alternative to 16U2 on: April 22, 2014, 11:59:40 am
of course we are all entitled to our opinions and mine is that pro is excellent for beginners.  i say this after providing 200 of the cheapies to several lab classes of engineering students. they are available with pins pre-installed but i thought it better to introduce some basic solder skills. my method involves mounting pins across the top of the pad instead of through the hole and only two out of hundreds failed to boot. and no lifted pads. the headers have even been removed on a few occasions w/o that happening.

as far as random pinout the actual "pro-mini" pads on the sides are consistent on all units ive purchased from many different asian sources, both ebay and aliexpress. only the enhanced signals like extra adc channels and serial varied and this was for improvement over the original sparkfun design. the current design also supports jumper selectable 3.3v or 5v operation which is another major improvement.

so considering  you can buy a dozen of these for the cost of a "real" arduino i highly recommend for beginners. if the official pro-mini, which was not designed by arduino btw, would compete in terms of cost and features  i would recommend it.
2  Using Arduino / Microcontrollers / Re: Alternative to 16U2 on: April 21, 2014, 07:41:07 am
personally, unless you are fixated on "shields",  i think pro-mini is the best target for those starting out. not only 1/10th the cost of the huge boards like duemanilove or uno  but actually more signal pins available. very friendly and standardized pin arrangement compared to those of the big brothers. much easier to build from scratch too.

admittedly nice being able to plug in a new chip on those big socketed boards but pro-mini is so cheap at $2-$3 shipped dollars its almost not worth it.
3  Using Arduino / Microcontrollers / Re: Alternative to 16U2 on: April 21, 2014, 07:14:00 am
or inside the USB shell on a nice long cable

NOW we are cooking with gas. i am always amazed at the number of people who still like to put that usb/tll converter on every board. talk about redundancy.
4  Using Arduino / Microcontrollers / Re: FT232 vs 16u2 on: April 18, 2014, 02:52:41 pm
since literally hundreds of these are required heres one of my favorites, as low as 50 cents bid or bo:


http://www.ebay.com/itm/USB-2-0-to-UART-TTL-6PIN-Connector-Module-Serial-Converter-CP2012-NI5L-/281297404719?pt=LH_DefaultDomain_0&hash=item417ea1c32f

for cable i like servo extensions, also pennies per:

http://www.ebay.com/itm/180674241111?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

arduino "rainbow" jumpers also work but hard to get more than a foot long. in any case ive learned to avoid usb micro connectors. separating from the pcb is #1 failure mode for rc controllers. .1" header pins not only cheaper but virtually indestructible.

edit: wrong link
5  Using Arduino / Microcontrollers / Re: FT232 vs 16u2 on: April 18, 2014, 09:14:55 am
until recently you were right about driver support. however windows being THE platform even back then wasnt an issue.

not only personal use but having to support many other arduino users last couple years i found ftdi a constant nightmare while silabs tended to just up and run. both hardware and software incompatibilities etc. for example 6 pin ftdi that used the correct dtr signal were rare or expensiive whereas cp1202 easy to find and cheap. and then theres was the chasing port numbers around depending on usb port used. so if you were a linux fanboy or sparkfun "victim" then ftdi didnt seem too bad. but if not fiddling with drivers and staying out of the poorhouse were goals then silabs is way to go.

ps even now its hard/impossible to find 99 cent ftdi with usable reset pin.
6  Using Arduino / Microcontrollers / Re: FT232 vs 16u2 on: April 17, 2014, 12:29:55 pm
imo it makes little sense to put a usb ttl circuit on most product boards. few applications require usb as part of normal operation, mostly just firmware updates. since you need a usb cable anyway makes more sense to put the usb converter there and save big time.

btw silabs cp2102 is far better behaved than legacy "ftdi" chips and cost considerably less. good to see the old technology fade away.
7  Using Arduino / Microcontrollers / Re: Add a SIMM to your Arduino :) on: April 11, 2014, 01:06:27 pm
haha... i LOVE steam punk.

actually while its true that using flash for most ram applications will destroy it in jig time that wouldnt be the main drawback which is write access. hundred times slower than flash. just wouldnt work for the kind of use ram is required, ie dso, frame capture, logic analyzer, etc. and serial ram is not cheap and not fast in my experience. realistically though sram might be the better choice there.

as far as capacity i was careful to mention mega (arduino mega) in reference to the  256kbyte comment. i do plan to give that a try but probably using m1284. even though that chip already has more ram than any other avr it sounds like a really cool rainy day project.

8  Using Arduino / Microcontrollers / Re: Add a SIMM to your Arduino :) on: April 10, 2014, 04:18:58 pm
joe, you dont seem to recognize the difference between ram and flash. by my calculation only .05% of cpu time to refresh and 256kbyte not 4kbyte. using mega on that same simm would give 256kbyte. i have i huge box of those am tempted to give that a try.
9  Using Arduino / Microcontrollers / Re: AVR Programmer on: April 01, 2014, 05:07:53 pm
I can't get it to program the Atmega8

 sorry, i was replying to the m8 comment, ive no experience with trying to do atmel 8051 variants using arduino as isp. i dont know anybody who has succeeded there either. personally i use custom socket board and software to do those.

btw, nice adapter board.

10  Using Arduino / Microcontrollers / Re: AVR Programmer on: April 01, 2014, 02:48:36 pm
I was hoping I could connect RX to MISO and TX to MOSI directly, but it appears I need other components.

actually it is possible to use a serial port to directly program avr (see ponyprog etc) but arduino as isp is easier and more reliable. if you have trouble with m8 its most likely a wiring error because there is no difference between that and t45 regarding programming algorithm.
11  Using Arduino / Microcontrollers / Re: Arduino @ 8MHz instead of 16MHz on: March 22, 2014, 07:34:29 pm
lol! obviously i was just trolling for trouble with that one.

seriously though, arduino chips are just about the best of the bunch for directly powering from batteries with 3v-4v being a good range. i forgot to mention the highly popular 3.3v dc supply fits right in there and that can be had from just about every ftdi dongle. " we doe neeeeed no steeenkin' 5v"
12  Using Arduino / Microcontrollers / Re: Arduino @ 8MHz instead of 16MHz on: March 21, 2014, 04:59:26 pm
1. rasy is right. except its "caveat insurancium compania".  ive personally run torture benchmarks on several part numbers for 3v@8mhz from freezing to boiling w/o issues. ok for hobby. apparently many commercial too judging from the market.

2. osc drifts very little during temperature but more for voltage. rs232 is workable for direct lipo power (4.2-3.6v) but only if properly calibrated at median. the real problem is divisors just dont work out for 115kbaud @8mhz. thats why a reasonably designed bootloader would choose 57k as default. little to do with osc stability.

3. no need to change bootloaders going from 16mhz to 8mhz. one size fits all. simply use next baud rate down.

4.  regulators would not "just eat too much power". ldo which is the only type that makes sense here draw picoamps.

5. "code" is not  always a mass noun. ie "morse and enigma codes proved useful during the war".

ps lipo or 3 rechargeable aa cells no regulator are personal favorites for 99% of my projects. they are really interchangeable.

13  Using Arduino / Microcontrollers / Re: Optiboot on Arduino Pro Mini 5v 16MHz not available on: March 21, 2014, 04:25:46 pm
Trouble is: There's no "Uno" either.

mainly because uno, duemilanove, promini, and aprox 200 others are all the same as far as that menu goes. the only ocd are those who demand a different entry for every brand of 16mhz board. if they had their way it would be several pages long and since gets truncated only 1% visible. 5-10 minutes to get to your particular favorite.
14  Using Arduino / Microcontrollers / Re: (solved?) Sudden power jump in sleep mode on: February 25, 2014, 01:32:16 pm
he already set pins to outputs which does the same thing. looking more and more like it was the ldo. unconnected pins there can also cause spurious draw. specially those 2980 clones.
15  Using Arduino / Microcontrollers / Re: ATMega328P on BB, no sign of life on: February 25, 2014, 11:38:54 am
Speaking of which, any cheaper alternatives?

my favorite is ebay usbasp for 2$-3$.  i found it more reliable and easier to use than my dragon or mkII not to mention you can buy a dozen or more for the cost of one of those. arduino as isp would be my second choice.

maybe try simple blink program before getting into bootloaders. if that works then the problem is unlikely the programmer.
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