Move 2x3 pin headers to either end of PCB

[charlespax]

Put one connector on the left and one on the right. This should be pretty much where the switches are. Make the design symmetrical.

[Tsillen]

You could also switch to a smaller pitch (1.27mm) or even just use "test points" contact. As 90% of the people that use it will never use the ISP header to program it. For the 5% that does they can just solder an header on the contact pads themselves.

This Also makes more space for the mechanical side of things.

[charlespax]

Now that the components are on the LCD side there is plenty of room to keep the regular 2x3 headers in the areas marked in yellow.

[starno]

I added some experimental punch-outs in between some ribs on the back of the enclosure. This gives optional quick access to the ICSP and the extra i/o.

If there is room on the board to align those pads in this area, it could be a really cool feature.

[samchoy88]

It is nice to move 2x3 pin headers to either end. However the space of the board is large, here are the components that I can't move.

1. USB connector
2. SD card connector
3. LCD cable connector
4. buttons
5. ADC
6. Battery connector

As the MCU must place nearby USB and shorten the D+/D- signal. That means the MCU cannot place far away from USB connectors.

• Currently, the punchouts position is on the cutout area (ligh blue in board) and keep out area (red in board) of the board, please see below picture.
• The RTC battery connector is relatively large in the board, it is necessary to avoid the keepout area and place nearby the edge of PCB. (SD card will be at the bottom right side, remaining the bottom left side available for RTC battery holder).
• No components are allow under LCD cable area, as it should reserved for LCD cable. (Only traces are allowed in the middle part of the PCB).

[charlespax]

I see how the USB connector would an issue. Some of the other things I think we can work around. I'll take a look tomorrow and see if I can come up with something.

[starno]

The punch-out area that is dimensioned above is still flexible to move up from its current location.

The width is fixed so that a programming header can fit through, but the overall length of the punch-out is longer than it needs to be and can be changed to match whatever you have room for

[charlespax]

Okay, it is not possible to put the 2x3 header in the current location of the cutout. You can see in the image below that when the header is 6 mm from mounting hole, the header is on top of the milled thermal break.

I think we can make it work if we have the header about 1.5 mm from the mounting hole. @starno can we make this work in the enclosure? @samchoy88 does a location in this area work for you?

[starno]

At the moment there is a structural rib that connects those mounting holes vertically. We can probably make it work by eliminating a section of it or reworking it in different location. Can that USB MCU be moved below the USB connector instead?

[starno]

Oh, the thermal break is the bottleneck? I can rework the horizontal ribs to move the punch-out further down to accommodate. This is preferable vs. moving the punch-out sideways from where it is now

[charlespax]

In this screenshot the yellow area are the absolute keepout areas. Also, we cannot put the connector on the isothermal plane and not where the battery is.

[charlespax]

If the vertical rib must stay where it is, we cannot have the 2x3 header in a cutout. Another option could be to have a vertical inline 1x6 header. Just a thought.

[samchoy88]

I am working on @charlespax suggested location. Here is the exact location of the 2x3 header.

[charlespax]

Cool. Even if we can't get the feature in the enclosure, this will be a good location for the headers. @samchoy88 I pick pretty much a location that looked about right. Try to keep the connectors on a 0.1" grid if you can.

[charlespax]

Here is where they are for Electronics version 0.9. I don't want to close this until we have a PCB and enclosure that play well together.

[charlespax]

Let's consider this done. Opening new issue for aligning the headers with the enclosure. https://github.com/PaxInstruments/t400-electronics/issues/97