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Please tell me I'm wrong


#1

As I’m in the early stages of making a FEZ Panda board for myself I tried to figure out the pin locations for all the new IO pins.

As we all know the headers of the Arduino has a flaw http://brettbeauregard.com/blog/2009/07/arduino-offset-header/ and now looking at the Panda board picture it seems to me that the new headers might not conform to the 0.1 grid. I’m attaching a picture where the Green lines indicate correct headers that conform to the 0.1 grid and you could use a perfboard on those. The Red line is the problem header. But judging by the photo, the Yellow line (header) is aligned with the problem header??

So my question is; Ignoring the bad Arduino header, will all the new FEZ Panda headers including the good Arduino headers line up to a 0.1 grid and a perfboard?


#2

I plugged an ethernet shield into a Panda today with no difficulty. Does that answer your question?


#3

he is wondering if the yellow line. The inside i/o row is off set and not spaced standard. The red line is known to be spaced out wrong and makes so you can’t do a normal protoboard on top. I will check with my prototype panda tonight.


#4

On the prototype panda it is fine. Spacing is tight but it fits. Mine was a prereleased board so it maybe different on the production board.


#5

Funny bstag, when I did my measurements, the board was NOT a simple fit on a breadboard/perfboard/stripboard - it seemed it was marginally out of tolerance. I ended up mounting my headers on the (admittedly prototype) Panda on an angle so I could at least get them into the stripboard. I was also told that the layout won’t change from the prototype to the production boards. I guess once we get the eagle files we can custom make a shield (or buy the protoyping board we saw a few weeks back!)


#6

The image below might be able to tell the story better.
yellow and red are aligned.
green is not aligned to both red and yellow.
I thing this is what Geir is questioning.


#7

You are well aware of the flaw in Arduino layout but we have no choice to to continue since this board is “pinout-compatible”. I hope the new pins we added do not make problems for your inventions but when something starts wrong then it is hard to make right later. Look at Rhino and Cobra for example, perfect pins layout right on the edge for easy access.


#8

Wouldn’t it be an idea to correct the “Italian” mistake by aligning the pins correctly, and provide some “pass-through” adapter?


#9

Gus;
Im not suggesting that you correct the error on the Arduino headers, that would be wrong and none of the Arduino shields would fit.
But if you aligned the new pins to the bad header, then the new IO header wont line up on a perfboard either. Then instead of having one header where we have to bend pins to align, we have a whole lot more.


#10

I see that the Prototyping shield is listed as a Panda component. Is it even possible to access the new IOs through this shield or are we limited to the Arduino headers?
(and No, I dont want to bend pins or drill new holes)

Can anyone verify that all headers align with the Prototyping shield?


#11

I still not have my Panda with me yet.
But here is my DIY solution that I’m going to do with my Panda

  • Use the existing Arduino’s pin compartible headers 2x6, 2x8) as the connectors to stakable shield
  • solder the two rows of male headers (as shown in the picture) to 12 and 14 holes on Panda,
    so we can hook the Panda on to the top of large size breadboard or perf. board and able to use those pins
  • use male right angle 2x5-pin header solder to UEXT connector on top of Panda board.
    So we can use the extension cable to connected to, for example, 128x64 Graphics LCD, etc.

This might not be the best solution, but I thing this would work for me.


#12

Seems ok to me. I was thinking of maybe modifying my domino this way.


#13

That is one great illustration Sam. Not only are you a programming electronics wiz but also a great illustrator. :clap:

Your DIY solution will work fine if all the stuff on your bottom perfboard doesn’t have to interface with anything on your top “Arduino” layer. Then you have to pull wires and that is the sort of thing I am hoping to avoid.

Well Sam, -as you of all people know the Panda is finally on its way so I will have my answer soon enough. If i’s like I fear we might have 68 misaligned pins instead of the original 8 pin Arduino error.

I know this is a fan site and negative comments are not that popular, but I hope the FEZ team has a look at this before they start building all sorts of shields for it.

Again, I hope I’m wrong about the layout :slight_smile:

By the way, any news on the eagle design files?


#14

As far as I know, right now they are working on the prototyping board too, (image below)

the layout in the Panda area should be one-to-one to between Panda and the prototype board,
so I don’t thing there are going to be the problem right there.

I haven’t heard or see the Eagle’s file post on the Panda Hardware page yet!

No we are not the fan. We are all help designing the Panda, and we ask for it. Look at the Panda Threads.


#15

Of course the protobard will line up. The point Im trying to make is that there is no way a regular spaced 0.1 perfboard is going to fit the good headers of the Arduino layout and the new IO pins at the same time.

Too bad none caught this earlier. :frowning:


#16

Yes it would have been nice. The good news is that our new base board is open source and so you can take it and modify it anyway you like. Soldering the base board is very easy since it is mostly headers and very large components.


#17

And when can we expect it? ;D