Uploading small sketches is fine. I can load the blink sketch via serial every time. It only manifests with larger sketches, even 20k sort of size.
Atmel does not seen to have ever claimed it's a chip internal problem, but rather they speculate that it's most likely a problem that may be caused by noise coupling from the chips clock lines pin(S) to the RX0 pin, so circuit layout external to the chip may be a variable that increases or decreases the possibility of one having the problem,
That seems to be a new piece of information, unless I missed it in the jumble.
oric_dan(333):
Atmel does not seen to have ever claimed it's a chip internal problem, but rather they speculate that it's most likely a problem that may be caused by noise coupling from the chips clock lines pin(S) to the RX0 pin, so circuit layout external to the chip may be a variable that increases or decreases the possibility of one having the problem,
That seems to be a new piece of information, unless I missed it in the jumble.
It was a passing comment by one (or a couple of) avrfreaks poster that apparently sought out ATMEL's help, he was told effectively to clean up his circuit layout. That coupled with the fact that the problem is never mentioned in the errata section of any published Atmel datasheet for the 1284P lends credence to that 'speculation'.
Lefty
It was a passing comment by one (or a couple of) avrfreaks poster that apparently sought out ATMEL's help, he was told effectively to clean up his circuit layout.
This probably explains why Bob's boards "don't" show the problem.
oric_dan(333):
It was a passing comment by one (or a couple of) avrfreaks poster that apparently sought out ATMEL's help, he was told effectively to clean up his circuit layout.
This probably explains why Bob's boards "don't" show the problem.
That could very well be and I will add or subtract from that speculation when my 1284P chip finally arrives.
Lefty
tack:
Uploading small sketches is fine. I can load the blink sketch via serial every time. It only manifests with larger sketches, even 20k sort of size.
In my tests, the synch problems manifest both with small (Blink) o large sketches. Simply, without RC filter the chip doesnt' respond to the data sent through the serial line.
retrolefty:
It was a passing comment by one (or a couple of) avrfreaks poster that apparently sought out ATMEL's help, he was told effectively to clean up his circuit layout.
Uhm. this has a sense for me. Since today, I've only tested the 1284P on a breadboard because I didn't want to make a board for the serial programming using the bootloader if I wasn't SURE that I could do that to upload a sketch.
Uhm. this has a sense for me. Since today, I've only tested the 1284P on a breadboard because I didn't want to make a board for the serial programming using the bootloader if I wasn't SURE that I could do that to upload a sketch.
Well that leaves you in a catch 22 situation doesn't it?
So maybe make provisions in your PCB to install a resistor/cap filter near the RX0 pin and just don't install the components and jumper around them with a wire jumper or a 'zero' ohm resistor if testing proves they are not required with whatever layout you end up using.
Lefty
The only times I have trouble with serial downloading is when I accidentally leave the DTR cap off, or forget to burn the bootloader first. I'm slowly getting better about that!
CrossRoads:
The only times I have trouble with serial downloading is when I accidentally leave the DTR cap off, or forget to burn the bootloader first. I'm slowly getting better about that!
So OK fess up. Did you purposely do some 'special' PCB layout for the clock/RX0 lines on your 1284P boards being aware of the possible problems of noise interactions with serial communications? Or did you just get lucky.
Lefty
In one of my earliest design postings here, someone like Grumpy_Mike mentioned that it was good practice to not have signals going under the crystal.
When I wirewrap cards, the crystal is right next to the xtal pins also, with no wires crossing them.
This also goes along with Atmel's Design Consideration app note, see Section 5.
Being an electrical engineer who designed for the defense industry, I know how to follow good design practices.
"Atmel AVR042: AVR Hardware Design Considerations" Rev. 2521K-AVR-03/11
retrolefty:
Well that leaves you in a catch 22 situation doesn't it?
ROTFL
So maybe make provisions in your PCB to install a resistor/cap filter near the RX0 pin and just don't install the components and jumper around them with a wire jumper or a 'zero' ohm resistor if testing proves they are not required with whatever layout you end up using.
Good solution
CrossRoads:
Being an electrical engineer who designed for the defense industry, I know how to follow good design practices.
EDIT:
link doesn't work
Link works, its a forum wide problem. No downloads are working.
Just figured out why I couldn't find an online link earlier - I was searching at maxim-ic.com for it
I can design, I just can't surf 8)
I am using one of CrossRoad's Bobuino boards for a project of mine. I have loaded variations of my sketch about 50+ times with no problems. The date code is 1050.
Sketch size currently is:
Binary sketch size: 28,640 bytes (of a 130,048 byte maximum)
Estimated used SRAM memory: 2,352 bytes
cyclegadget, how did you get it to display SRAM memory usage?
How does one tell the datecode? Is it stamped on the chip under the p/n, like where
mine says 1216?
I have a bit more of information. First off, I've been reading through the interminably
long thread "ATmega1284P: End to End using 1.0 IDE", and there were gazillions of sketch
uploading and other problems over there, fuse settings/whatever. Was anything finally
resolved, or just a bunch of suggestions proferred?
http://arduino.cc/forum/index.php/topic,80483
My bit of information is, I've been uploading good-sized 32KByte sketches to my 1284 by
the bushload, using IDE 1.0 and 1.3, and using both FTDI cable and FTDI Friend, and not
seen even a single glitch.
I do have the 1284, and not the 1284P, chip programmed with the Bobuino variant of
maniacbug's v4.5 optiboot.
Secondly, my board here is a hacked proto typing shield with a lot of soldered wires and
a lot of wirewraps. In fact, the connection to the RX0 pin is a 3" long wirewrap wire
that I have now purposely strung "between" the crystal pins, just to try and inject some
extra noise onto RX0.
So, no low-pass filter on RX0, RX0 signal passing in between crystal pins, large 32KB
sketch, and nary an uploading glitch after several dozen burns. So, all in all, ...
no problema. Maybe the moon here is in its happy phase, or because I'm playing
Mozart. ???
oric_dan, yes, 1216 is the data code.
oric_dan:
cyclegadget, how did you get it to display SRAM memory usage?
I use ERW Arduino IDE http://arduino.cc/forum/index.php/topic,118440.0.html
I had to added the Bobuino board .txt file to make it work but, it is a very similar process to the standard Arduino IDE.
Also, I just realized that my chip is a 1284P if that makes a difference on my earlier statements. I know for a fact that I am using the maniacbug bootloader as I installed it myself to make sure I had the latest and greatest bootloader.
CrossRoads:
oric_dan, yes, 1216 is the data code.
And it is usually decoded as year 20(12) and week(16) or possibly batch(16)
Lefty
Thanks in regards the datacode. So I have chips from a fairly recent batch.
Also am using the 1284 rather than 1284P. Maybe it's the 'P' pico-power version that
has the RX0 sensitivity problem, as I figure draping the RX0 line around the xtal pins
like I did should aggravate any noise issues, but uploads are solid. I plan to get some
1284P chips soon to try.
Does anyone know of a very large sketch I could try uploading? For my 32KB sketch, I
just created a humungus initialized data array, clearly far over the RAM size for the
chip.
One other question - there was talk on some of the other threads about Arduino-central
producing a standard pinout for 1284P chips. Is that a possiblility?