Make sure the backup battery is good, correctly in place, and making good contact.

i added the caps and still 20v in and 19ish out

i have tried this on two brand new regs

one is 5v the other is 15v

could i have damaged them running without caps ?

Time to post a picture if you can, the whole circuit, maybe several pics if that works best.

1. Is the binary sketch size reported when compiling the same for the two?
2. Are the leads on the crystal and load capacitors short?
3. Do the load capacitors match the crystal? Load capacitance as specified on the crystal's datasheet is not the value for the load capacitors.
4. Run the Blink sketch, does the LED keep in sync with the second hand on a clock or watch? If there's a 20% error in the clock speed, it will get out of sync quickly. Alternatively, just run Blink on both.

...the range I need to measure ranges from 0.5 mega ohms to 100,000 mega ohms...

Really? 100,000 MΩ, or 100 GΩ? That's lots o' ohms. There might be some unusual considerations to get reasonable accuracy with such high values.

I haven't tried AVR Studio, but have used WinAVR a bit with some degree of success. I did find 43oh.com but haven't spent much time there yet.

I splurged to the tune of $12.90 and ordered the maximum allowed (three) LaunchPad kits (I'm a sucker for free shipping), and it looks like they will ship soon. Being a relative microcontroller noob, I only know AVRs, and while they seem to be just super devices, part of me feels compelled to explore others. Not sure what I'll do with these, or even when, but I'll have them just in case I get bored or something.

If I were to choose one aspect of Arduino that makes it so easy to use, it would be the inclusion and availability of more-or-less "standard" libraries for common functionality, e.g. SPI, Wire (I2C), Serial and its software cousins, etc. Do these exist for "real" microcontroller development? I poked around AVR Freaks and such a bit, perhaps not enough, but didn't find much along those lines. It sure seems like there could be a lot of wheels reinvented. Maybe standard libraries exist within the bounds of various MCU development organizations, and that works well enough.

Hi Doc! Would love to kick around ideas. This is a pretty informal thing so far, so the more the merrier. It's just two of us, and we usually just chat about whatever occurs to us. (We may actually have one agenda item for the next meeting, and that is to configure a couple XBees for point-to-point communication.) Pontiac's not a bad drive, I go there occasionally for work, and there's lots of places in between, too.

Thanks for posting! ... Jack

The "IEEE Spectrum Tech Alert" email arrived with the subject line "With the Arduino, Now Even Your Mom Can Program". This evidently caused some serious backlash, as later I received an exceedingly apologetic email from IEEE Spectrum Editor in Chief Susan Hassler which said,

I'm an IEEE member, and a mom, and the headline was inexcusable, a lazy, sexist cliché that should have never seen the light of day. Today we are instituting an additional headline review process that will apply to all future Tech Alerts so that such insipid and offensive headlines never find their way into your in-box.

When I first read the article, the quote was attributed to Massimo Banzi. Now I see that it's been removed from the text. I was glad to see an Arduino article, and personally I wasn't terribly offended, but then again, I'm a Dad.

Are resistor leads steel? I never even thought about them.

But if so then the answer is 100%

______
Rob

I think a lot are, capacitors and other components too. They are pre-tinned however. They stick to my cutters sometimes as they have somehow become slightly magnetized. Rectifier diodes are an exception for obvious reasons.

In addition, do not leave any pins floating.  They will eat way any power savings you gain from putting the processor to sleep.

I found that setting unused pins as inputs, and turning on the pullup resistors works well.

I'm late to this party (not sure how much of a party it was), just starting to look the thing over. I might pick up a couple, doesn't look like a super impressive MCU, but for the price I figure I can't go too far wrong.

Anyway, I read through a lot of old posts about it, mostly 2Q and 3Q2010, and mostly debating its merits, prospects, and the difficulty of actually obtaining one during the initial crunch.  So now I'm just wondering if folks are still playing with it, what they've used them for, etc., now that the initial hype has calmed down.

I forget the web site, had a unique Captcha-type thing, "What is the value of this resistor?"

Yes, capacitors are required, but their absence doesn't explain to me why the output isn't pretty close to 5V. Technically speaking, a transformer doesn't supply positive and negative, but AC. What exactly is the "transformer" being used here? DC needs to be supplied to the circuit as illustrated.

That's always quite an accomplishment! 

I'm using 0.020" Kester 245, which is 63/37 and has a no-clean flux. Works fine, no problems so far. Got it from All-Spec. I also considered Kester 275, couldn't tell the difference just from reading the description, so I just tossed a coin.

I forgot: encoder0Pos should be declared "volatile"

And should be accessed atomically in loop() ?

Hey that's great news! Your place sounds great, although 180° from Arizona, ha! We get winter here, but not like Vermont. Starting to lay in next year's firewood, but haven't fired the wood stove up this season yet. Might have to give you a shout sometime on the Google Graph stuff. I've just felt my way along the wall in the dark with it once or twice.