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[on:]

HI all.

The folks over at OMS drafted up 3 possible additions to their prototyping shield offerings.  They asked that we show them here and ask for your comments.

All of the designs currently feature a little extra width and this serves two purposes.  First, it provides for very legible and easily seen markings of the pins, which will be marked on both the top and bottom of the board.  Second, by placing the pin makings on the outer edge of the board it allows the full space between the headers to be utilized for component placement.  Additionally, the topside silk screen on each depicts the foil pattern that is on the bottom and they are cut out for the Arduino USB connector.  This was done to allow use with the more common stackable female headers with 10.5mm pins.  Each also provides the ability to accept regular perf-board as shields by correcting the right-side connector spacing.

This first one is just a sea of 406 uncommitted plated through holes.  It has a single set of header rows and is ideal for use with stackable female headers, or male headers if it is to be the top board.

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This one provides two DIP areas, one with 19 rows and the other with 10 rows each with 3 connected holes on both sides and power busses between the rows.  It has 69 additional hole pairs and 2 additional hole triplets to simplify the mounting and connection of other components and connectors.  It has a single set of header rows and is ideal for use with stackable female headers, or male headers if it is to be the top board.  It also includes a properly located area to connect to or provide connection to the ICSP header on the Arduino.

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The third one has an identical pattern to the second one with the exception that it has a double set of rows for headers so that is can be used to provide staking via offset male/female headers.  This has a couple of advantages over stackable headers due to the size and shape of common male header pins.  They are .6 mm square rather than the .6mm x.35mm rectangle of the common stackable female header.  This allows them to make better contact with the Arduino sockets, especially on older more worn boards.  They are also much stronger due both to the square section and their shorter length and much less prone to bending and breaking. However, that said it could also be used with stackable female headers if one wished.

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www.aztecmcu.com

[Reply #1 on:]

I like the 2nd a 3rd ones.  Do you know when they will be available?

[Reply #2 on:]

I'll have to look at them in more detail, but compared to your previous prototype boards, in addition to my previous complaint (in email) about stackable headers which is addressed in the boards with offset headers (or as you mention female headers), the top side silk screening did not indicate which pins are connected to which.  As I was looking at it, I had to keep flipping the board over to make sure I had the alignment correct.  Please have the silk screening indicate what pins are connected to what, particularly as you will soon have several different board layouts.

I also did a circuit continuity test, and the two power rails down the middle aren't connected to ground or 5v.  Now obviously, that can be more flexible, but I suspect it will be friendlier to people like me moving from breadboard to prototype shield (or use other prototype shields that do connect the rails) if the connections are made.

[Reply #3 on:]

I'll have to look at them in more detail, but compared to your previous prototype boards, in addition to my previous complaint (in email) about stackable headers which is addressed in the boards with offset headers (or as you mention female headers), the top side silk screening did not indicate which pins are connected to which.  As I was looking at it, I had to keep flipping the board over to make sure I had the alignment correct.  Please have the silk screening indicate what pins are connected to what, particularly as you will soon have several different board layouts.

The previous boards are to be updated with top-side silk screening of the connections, bottom side identification of the pins and the new shape.  We also added a link to the stackable headers from the web page for ordering the previous boards.

I also did a circuit continuity test, and the two power rails down the middle aren't connected to ground or 5v.  Now obviously, that can be more flexible, but I suspect it will be friendlier to people like me moving from breadboard to prototype shield (or use other prototype shields that do connect the rails) if the connections are made.

There are too many possible configurations for the power rails to make it generally beneficial to connect them to one power pin or another.  On the Adruino, there are 3 choices (5V, 3.3V and Vin) and then there is the possibility of external power, two voltages and no ground connected via wires, which side should be power and which side ground, or even using them for something else besides power. 

[Reply #4 on:]

I like the 2nd a 3rd ones.  Do you know when they will be available?

We don't have a time frame yet.  OMS wanted to wait to get feedback from this site and some other sources.

[Reply #5 on:]

I'll have to look at them in more detail, but compared to your previous prototype boards, in addition to my previous complaint (in email) about stackable headers which is addressed in the boards with offset headers (or as you mention female headers), the top side silk screening did not indicate which pins are connected to which.  As I was looking at it, I had to keep flipping the board over to make sure I had the alignment correct.  Please have the silk screening indicate what pins are connected to what, particularly as you will soon have several different board layouts.

The previous boards are to be updated with top-side silk screening of the connections, bottom side identification of the pins and the new shape.  We also added a link to the stackable headers from the web page for ordering the previous boards.

Sounds good.  The lack of silk screening makes it harder to use.

I also did a circuit continuity test, and the two power rails down the middle aren't connected to ground or 5v.  Now obviously, that can be more flexible, but I suspect it will be friendlier to people like me moving from breadboard to prototype shield (or use other prototype shields that do connect the rails) if the connections are made.

There are too many possible configurations for the power rails to make it generally beneficial to connect them to one power pin or another.  On the Adruino, there are 3 choices (5V, 3.3V and Vin) and then there is the possibility of external power, two voltages and no ground connected via wires, which side should be power and which side ground, or even using them for something else besides power. 

Yes, I can imagine that.  The question is who are the boards targeted towards.  Do you target newbies who might assume a 5v and ground connection on the rails, or do you target people who want the minimum connections, and maximum flexibility?  Since I am just starting out to use prototype boards and my other boards used the standard 5v/ground on the middle, I just assumed the OMG board to be the same way.  It isn't a big deal either way, but I can imagine you might get somebody with floating pins because it isn't grounded.