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Topic: New Mega2560 Layout (Read 2880 times) previous topic - next topic

CrossRoads

I've been playing with a 2560 layout so I could use it as a drop-in processor on projects into a 104 pin header.

This is what I have, all routed and with the caps, crystal, and resistor on the bottom, and ICSP and FTDI header for easy programming.

Thinking about pin labels - do you think having them around the outside like this is clear, or would moving a bunch inside the pins would be more clear?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

larryd

#1
Jul 20, 2014, 08:16 am Last Edit: Jul 20, 2014, 08:22 am by LarryD Reason: 1
I think the way you have it is best.
Would you want a jumper option on +5 on the the FTDI?
No technical PMs.
The last thing you did is where you should start looking.

CrossRoads

Yes, that can be added. Jumpers to allow 5V and DTR to be disconnected.

Am waffling on pin names tho - go with raw port names like I mostly have now, or go with the IDE names, such as D0,D1, Dxx and A0, A1, Axx?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

larryd

#3
Jul 20, 2014, 07:53 pm Last Edit: Jul 20, 2014, 07:57 pm by LarryD Reason: 1
I am curious, how will this board be used?

EDIT:
If you enlarge the PCB add 6-32 mounting holes in the corners then you would have room for both the controller names and the IDE name side by side.
No technical PMs.
The last thing you did is where you should start looking.

CrossRoads

My plan is to have a 104 pin socket on perfboard, or a PCB eventually, that this would plug into.
Looking at a project where this and several other processors would be connected together.
Going to wirewrap them to start until I find a connection/interface scheme I am satisfied with, and then perhaps go to a larger PCB for them all.
This provides kind of a DIP option for me, and if something blows I can pull it out and  insert another.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

No mounting holes - part will be treated like a DIP part, just plugged into a socket.
Or it could use wirewrap socket pins for legs instead.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Robin2


This provides kind of a DIP option for me, and if something blows I can pull it out and  insert another.


I would find that sort of thing more useful if there were just two rows of pins like a regular dip chip. I realize that would make it longer and would probably make the routing more complex.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

CrossRoads

Well, that's the engineering tradeoff, isn't it?
Remember the Intel/Motorola processors of the past, 1.5" to 2" square parts with 2 and 3 rows of parallel pins underneath? That's what I am after here.
Someone's already done a 2 x 50 DIP version of the Mega, I think using the leadless package.  I wanted something more compact, yet still relatively easy to solder.
At 47.8 x 45.3, this still fits into the inexpensive 50mm x 50mm PCB also, vs jumping up into the 50 x 130mm range.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

robtillaart

Great idea, would allow for easy replacement of processor.

Quote
Am waffling on pin names tho - go with raw port names like I mostly have now, or go with the IDE names, such as D0,D1, Dxx and A0, A1, Axx?


Go with raw port names, people that will use the " plug in mega " will know the translation
Rob Tillaart

Nederlandse sectie - http://arduino.cc/forum/index.php/board,77.0.html -
(Please do not PM for private consultancy)

CrossRoads

That's what I was thinking too.  And then making adjustments in pins_arduino.h can be more flexible too.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

This is one of the DIP style 2560 layouts that is available (but backordered apparently)
https://jkdevices.com/arduino-megamini
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

luisilva

I think your design is better than that! And you don't things that you don't need, like the USB.

CrossRoads

I've ordered a set of PCBs, we'll see how they turn out in a few weeks.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

larryd

#13
Jul 21, 2014, 04:48 am Last Edit: Jul 21, 2014, 04:52 am by LarryD Reason: 1
This is kind of interesting might be able to get some ideas here.
http://www.elecrow.com/tqfp64-breakout-board-08mm-p-355.html

$1.00  :smiley-eek:
No technical PMs.
The last thing you did is where you should start looking.

CrossRoads

Perhaps.
www.schmartboard.com and www.proto-advantage.com offer lines of similar components.
schmartboard are set up to be easy to solder. proto-advantage has board-stencil-solder kits, and will also order parts from digikey and do assembly for you.

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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