Does this thread help?

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1193955465

Quote by: Windell

Does this thread help?

http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1193955465

It did, sorry I just edited my post

One thing to check: Make sure that your USBtinyISP is *not* providing power to the Meggy-- that is, make sure that the power jumper by the ribbon cables is disconnected, and make sure that Meggy is providing its own power.

(Alternate scheme: USBtiny provides power, but Meggy Jr is switched off. Just make sure that both are not on at the same time-- that will guarantee trouble.)

Yeah, my USBTiny is not providing power... Goodness, I wish I had socketed the 168 now

>Goodness, I wish I had socketed the 168 now

Do you have a reason to believe that the '168 has been damaged?

No, but if I had, I could use my target board to program it... Well, now that i think of it, I don't need the target board... There's an ISP header build in - Duh! Ha ha... I'll either have to try to get AVRDude set up on my Mac or resign to using my PC again, I guess

> I'll either have to try to get AVRDude set up on my Mac or resign to using my PC again

The best way to get the AVR toolchain on the Mac (including AVRdude) is to install this bundle:
http://www.obdev.at/products/avrmacpack/download-de.html

Hmmph! I installed AVRDude and everything looks good with that, but when I tried to program the Meggy, it's still a no-go. Here's the output:

Okay, so now we're debugging *two* different problems: USB-TTL cable programming and ISP programming.

For the USB-TTL programming, you can use the scope to test the USB-TTL cable. Connect the cable to your computer but not to Meggy Jr. The 6-pin end of the cable has bits of exposed metal, which you'll want to look at with the scope. Set the scope to 1 V/division scale, auto trigger, 100 ms/division, and look to see that pin 6 (green) is high, pin 4 (orange) is high, and pin 1 (black) is low. When you hit "upload to I/O board," pin 6 should go low for an extended period of time. (OK if it's not consistently down.) Try again, looking at pin 4. You should see the signal dip low-- briefly-- a few times. If this is the case, your cable is probably working correctly.

On the ISP programming front, *first* make sure that you can program your Arduino with your existing setup-- that will verify that your programmer and software setup are working well. The "initialization failed" error can be caused by any of the connections from that port to your chip, so check them all, and make sure that you don't have any accidental shorts on those pins.

Sorry to bring up an old thread, but I haven't been able to get this working still... I've tried everything in here except using an oscilloscope, I really don't have a working one, nor do I know where to go to use one... I got a new computer, everything has worked so far (Arduino, USBTiny, AVRDude), but still nothing works with my Meggy Jr...

Well, this is weird indeed. And I'm sorry that it has dragged on so long.

Let me make sure that I understand what's going on here: Your Meggy Jr is basically working, EXCEPT that it can't be reprogrammed, right? It's got power on when you're trying to program. Your computer is set up and able to program an Arduino through a USBtiny, but not the Meggy Jr, and USB-TTL programming is not working either. Correct so far?

Next... You're sure that the ISP-6 header is on the bottom of the Meggy Jr, and that pin 1 of the cable is facing the right way, right?

I'm suspicious that perhaps this is a "reset" problem, because the only pin common to bootloader (USB-TTL) programming and ISP programming is Reset. If that pin were held high-- by a short to +V, or if the value of the reset pull-up resistor (R4, supposed to be 10k, the one small-size resistor) were wrong, it might not be possible for the Meggy Jr to initiate programming. Also possible: a bad solder joint at pin 1 of the microcontroller. Check these out carefully. You might also, with the power off, measure the resistance between pin 1 and +V.

Hmm.... R4... 10k? My R4 is 220... It's been so long since I've made this now... Maybe it was a 10k it didn't come with and I mistakenly thought it was a 100 so I used a 220 to replace it? I'm not sure. All my resistors look the same size, so I'm guessing that's the only problem. Would that cause the issue? And should I just replace it to get it working? (If I can't find a 10k here, I know I have 1k... Would that work?)

Here are some pictures just in case you can pick up on anything else that wrong.

Yeah... that would do it. Substituting a 220 ohm resistor for the 10 k would almost certainly have no effect *except* preventing programming from being possible.

The value there needs to be at least 5 k, but 10 k really is better. It will also work but for ISP programming only if you just remove the resistor. If you leave the resistor off, that disables the "auto-reset" feature of Arduino-style programming. If you want to leave the resistor off and program through the USB-TTL cable, you'll need to (1) reburn the default Arduino bootloader (with the USBtiny) and then (2) every time you reprogram, press the reset button at the right moment.

If you don't have a 5k - 10 k resistor, you can make one by stringing several 1k's in series, or you can e-mail our store and we'll send you a replacement. But for the moment, *just remove it* and things should mostly work okay.

I had to dig through a couple boxed from Mouser, but I finally found a small pack of 10ks. I'll get that replaced in a little bit and hopefully get to start programming for it soon!

Thanks for the help, I hope this was the problem!

Phew! Finally. That took way too long... Now I feel bad that it was such a simple problem I had overlooked. Thanks for being patient with me. It all works now