Problem with RBBB/Atmel168

Questions about the Really Bare Bones Board
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jhornbr225
Posts: 7
Joined: Tue Dec 23, 2008 8:20 pm

Problem with RBBB/Atmel168

Post by jhornbr225 » Tue Dec 23, 2008 8:58 pm

Today I assembled my first of two RBBB kits that I got around Nov 7th. The service was excellent, prices were great, shipping costs and response time were great. I just thought I'd get all the kudos out at the beginning.

Let me start by saying that I have been in electronics for about 20 years, so constructing the RBBB should not be too hard.

I got it assembled, along with the P4 serial board and tried to get it to take a program, but found that I could not get the LED that I tied to pin 13 to light. Even when I press the reset button the LED does not light. I looked over the board and checked for power and ground at the pins stated in the schematic at the bottom of the document RBBBv1.6.revB2. So far everything looks good. The power LED on the board is on solid. I decided to take things back to the most primitive level and just plug the chip into my breadboard.

I ran +5VDC from my regulated power supply to pins 7 and 20. I ran common to pins 8 and 22.

I ran common to the center leg of the resonator, and the outside pins got to 9 and 10.

I have a 10K resistor going to pin 1 from +5VDC, with a jumper that I can put to common to reset.

On pin 13 I have a 330Ohm resistor and an good LED in the correct polarity. I took the end of the resistor out from the chip and tied it to +5VDC to make sure it lit, then put it back on pin 13.

After all this, I have the same result, no light from the LED on 13. I am reading about 80mV or so on pin 13.

I have not gotten the scope out yet to determine if the resonator is oscillating, but I am reading about 0.6VDC on the 2 outer pins with the DVM.

Got any ideas?

On another note, I bought a P4 Serial board and a serial cable so I do not have to use USB. There are three rows of 6 pins on the end of the board opposite the DB9 connector. The two sets closest to the outer edge of the board are tied together pin for pin. The third set in is the "live" pins coming from the inverter. The silkscreen on the board (P4B) matches the silks creen on the 6 pins on the communication end of the RBBB rev B2. Am I correct using that "live" set of pins directly into the header on the end of the RBBB, or do I have to invert RX and TX? I ended up putting the female headers on the RBBB and the males on the P4. Now that I think about it, I should not have done that, as I only have one set of females and two sets of males since I ordered two kits. Looks like I have a little desoldering to do.

Thanks in advance for any help/opinions/suggestions that anyone can offer.

ndpm
Posts: 6
Joined: Tue Nov 18, 2008 12:49 pm

Re: Problem with RBBB/Atmel168

Post by ndpm » Wed Dec 24, 2008 3:10 pm

I'd try some other pins to see if the problem was global. Are you using the provided LED test program that comes with the Arduino IED?

paul
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Joined: Mon May 12, 2008 4:19 pm

Re: Problem with RBBB/Atmel168

Post by paul » Fri Dec 26, 2008 3:10 pm

jhornbr225,

Sorry for your grief. We finally have some new P4 docs that Brian Riley of Wulfden.org did. He and I jointly developed the P4.
On another note, I bought a P4 Serial board and a serial cable so I do not have to use USB. There are three rows of 6 pins on the end of the board opposite the DB9 connector. The two sets closest to the outer edge of the board are tied together pin for pin. The third set in is the "live" pins coming from the inverter. The silkscreen on the board (P4B) matches the silks creen on the 6 pins on the communication end of the RBBB rev B2. Am I correct using that "live" set of pins directly into the header on the end of the RBBB, or do I have to invert RX and TX?
Just jumper the P4 pins straight across.

Here are some things to try - mostly just guesses. - Check the polarity on the chip - also push it firmly into the socket.
Reheat any solder joints that look suspicious.

Check power at proper pins on the chip to make sure it's not a bad connection somewhere in a trace or solder joint.
Check the power pins on the P4 inverter - it's getting its power from the board - so that could be an issue.

It's also possible that you have a bad PCB - I run across 1 or 2 per 1000 or so, so it hasn't been a huge issue, but I have seen it.
I guess there's some chance you have a chip that didn't get programmed.

Write back if you haven't found the problem and I'll see if I can think of anything else.

If you've got anther kit, you might try constructing that to compare and swap with for troubleshooting.

Paul

jhornbr225
Posts: 7
Joined: Tue Dec 23, 2008 8:20 pm

Re: Problem with RBBB/Atmel168

Post by jhornbr225 » Fri Dec 26, 2008 6:45 pm

Paul, thank you for the response. I know the holidays can be a busy time, and I'm glad you found the time to respond.

Like I said, I pulled the chip off the board and plugged it directly into my breadboard and hooked up all the pins that I though were needed. (Power, Common, Resonator, and a resistor on the reset pin to 5V.)

Should I do anything with RX and TX to ensure that no noise is coming in on them, confusing the chip?

Is pin 13 Active high or active low? I have a resistor coming off the pin, to the LED, with the proper end of the LED tied to common. Do I need to reverse the LED and tie it to the 5V line instead of the common?

From what I read, the simplest thing I should be able to do is reset the chip and get the LED to blink once showing that I reset it. Then I can move forward with trying to communicate with it. Without the LED even doing the most basic operation, I can't confirm if I am even communicating. At least at this point I know, I dont need to reverse my RX and TX.

Thanks again, hope you had a good holiday.

Jason

jhornbr225
Posts: 7
Joined: Tue Dec 23, 2008 8:20 pm

Re: Problem with RBBB/Atmel168

Post by jhornbr225 » Mon Dec 29, 2008 10:18 am

By golly, I think I've got it!

Thank you for all your help. I found that I was using pin 13 on the chip, not D13. When I tied to digital 13, it started to work as expected. I am able to communicate and upload sketches now.

Thank you,

Jason

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