SX in a DIP package. ExpressPCB "FREE" prototypes. Submit your design here. (EN

Bean

There seems to be alot of interest in an SX in a small DIP package.

I will be ordering prototype boards from ExpressPCB on Dec 11 (deadline for entries is Dec 10, 6:00EST) they will arrive on Dec 14. I will put as many entries as I can on the board. When they arrive I will cut them apart and mail them to you (send your mailing address in a private message or to terry@hittconsulting.com).

You will get 3 boards of your submitted design. These are only prototypes so there will NOT be any soldermask or marking layers. And only two layers (top and bottom).

To submit your design post the ExpressPCB file in this thread. Your design will be public domain, so keep that in mind.

I'd like to limit it to 8-Pin, 14-Pin, or 18-Pin designs.

So fire up ExpressPCB (or download it from www.expresspcb.com) and get to work.

I have attached a design with the SX20 to get you started.

Bean.
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Post Edited (Bean (Hitt Consulting)) : 12/19/2007 12:20:14 PM GMT

Peter Verkaik

Hi Bean,
Attached are my latest SX20DP8 (schematic and pcb).
Since I never use expresspcb it probably needs some adjusting.
The pads and components are in place. What might need a little
shifting are the vias and resonator pads.
Also, does expresspcb allow for filled areas with pouring over nets?

regards peter

Bean

Peter,
· If you right-click on a pad, you can select "Top Layer Pad Shape" or "Bottom Layer Pad Shape". There are options for thermal connection, solid connection, or no connection to the fill.

[noparse][[/noparse]Edit] I took the liberty of touching-up the board. See if this is okay.

Bean

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Post Edited (Bean (Hitt Consulting)) : 12/5/2007 5:41:56 PM GMT

Peter Verkaik

Looks much better now. Thanks.
Is it possible to remove dead copper from the filled area?
I tried to link the pcb with the schematic, but there appear
no net wires. How can I check/set nets to copper lines?

regards peter

Post Edited (Peter Verkaik) : 12/5/2007 6:25:20 PM GMT

Bean

Peter,
Sorry I didn't download the SCH file so I guess the net list is gone.
When you use the tool to draw a filled plane at the top of the screen is a radio button to draw a "keep out" area.

Bean

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Peter Verkaik

Bean,
You stated when posting your dip8 design, that pins 1 and 8 must extend to
both top and bottom of the pcb to allow both insertion into a dip8 socket
and provide the sxkey pins. Did you have a particular pinheader type in mind?

regards peter

Bean

Peter,
I was thinking a header pin that is long on both side (like the 3 pin header that comes with the parallax LCD extension cable).

Bean

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Peter Verkaik

Bean,
I just tested a pinheader with 0.6mm diameter round pins, long side of pins is 6mm, short side
of pins is 3mm, isolation strip height is also 3mm (so total height is 12mm).
If I mount the header on the bottom of the pcb but with the long side
of the pins on top of the pcb, I get 4.6mm pins on top (pcb thickness 1.4mm)
which is enough to hold the sxkey.·And the 3mm pins on the bottom side are long
enough for a precision (no spring contact) dip8 socket.

regards peter

Bean

Peter, do you have a part # for that pin ?

Bean

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Peter Verkaik

I think these will do:
http://www.sparkfun.com/commerce/product_info.php?products_id=117#

The short side is 3mm.
The long side is 5mm instead of 6mm, but the sxkey even makes good contact
on my 3mm short side. With 5mm long side and 1.4mm pcb, there will be
3.6mm for the sxkey connection.

regards peter

Bean

Here is a SX20 in an 8 pin DIP.

This one features:

· Direct connection of SX-Key to pins 5-8.

· All parts on top side (except optional resonator)

· Access to pins RB.0 thru RB.3 on pins 1 thru 4 respectively
··· Allows use of comparitor & pin interrupts
····RTCC is connected to RB.3

If you only need 4 I/O pins this design is really easy to program and debug. And allows you to use an external resonator/xtal/etc.

Bean
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Post Edited (Bean (Hitt Consulting)) : 12/7/2007 5:37:12 PM GMT

Bean

Here is a better version of the SX20 in an 8 Pin DIP

This one features:

· Direct connection to the SX-Key/SX-Blitz programmer on pins 5 thru 8.

· Access to pins RB.0 thru RB.3 on pins 1 thru 4 respectively.
··· Allows use of comparitor and pin interrupts
··· RTCC is connected to RB.3
··· Series resistors on all I/O pins (to protect from burn out)

· Optional resonator on bottom

· Low battery indicator using RA.2 and RA.3
··· Make RA.3 an INPUT with TTL level triggering (1.4V regardless of Vdd)
··· Make RA.2 HIGH
······ If RA.3 = 1 then Vdd is ABOVE threshold set by the two resistor values
······ If RA.3 = 0 then Vdd is BELOW threshold set by the two resistor values
··· Make RA.2 an INPUT or LOW afterwords to save current

This can easily be made into a 14 Pin DIP with 10 I/O. I will post that as soon as I make it.
[noparse][[/noparse]EDIT] I posted the 14 Pin version. It also has optional pull-down resistors on pins RB.4 thru RB.7, and RA.0 and RA.1 (just because I could).
In fact you could take the 14 pin version and just cut the right 3 pins off to make an 8 pin version.

These features are useful because I would like to make (or offer to make) so custom ICs, and it would be nice to have the series resistors to the end user can't burn-out the pin. And the low battery is just a use of unused pins, but useful too.

I'm thinking stuff like a LED chase device for the 8 pin, and·"knight rider" type devices for the 14 pin.

Bean
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Post Edited (Bean (Hitt Consulting)) : 12/8/2007 6:18:14 PM GMT

Sparks-R-Fun

I tried to verify the wiring of the 8-pin dip design by Peter Verkaik but found I had insufficient time to do so. What I did was create three 4-pin components, one for the SX-Key, and one for the left and right dip sides respectively. I added these to the schematic and then to the PCB layout. The goal was to use the net-list highlight feature to verify that all the pads and pins had been routed properly.

The end result should be electrically equivalent to the one Peter posted and Bean modified. However, I changed some of the trace routes so that the design made sense to me. (It may not make sense to anyone else!)

Sadly, that is as far as I was able to progress before I realized I was out of time.

- Sparks

Peter Verkaik

Sparks,
The lower left pin (pin 1) ·is not connected to VSS.
(or so it appears on my screen).

regards peter

Bean

Sparks,
I think this is what you had in mind. I will add it to the board.

Bean

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Sparks-R-Fun

Peter,

Thanks for noticing that. (Last minute changes often ruin a design!)

Originally the connectors I added were placed off to each side of the circuit board leaving the original pads in place. Right before I posted I moved them onto the circuit board itself. At that time I did not notice such action isolated the lower left pin from Vss and the pin just above it from Vdd.

I have deleted these extra connectors from the attached design, which seems to have restored the power connection for the lower left pin and the pin just above it. Thank you for catching that!

- Sparks

Sparks-R-Fun

Bean,

Yes, that looks correct. Thank you!

- Sparks

Bean

· I will not be sending the file until tomorrow morning. So if anyone wants to submit a last minute entry, feel free. If you post it before tomorrow morning (6:00AM EST), I'll do my best to get it on the layout.

· Peter and Sparks, feel free to submit another design too.

Bean.

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Sparks-R-Fun

Bean's offer is too tantalizing to pass up! So here is my attempt at an 8-pin DIP circuit. I modified the design by Peter Verkaik to better match what I personally want a tiny SX to do. At the present time I have need of some inexpensive temperature sensors.

In order to fit more surface mount components on the board I dropped the resonator pads and moved the SX-Key connection entirely to one side. This should still allow for relatively easy programming connections. Four of the SX pins (A0, A1, B0, B1) are brought out to pins on the other side. On the top of the board three SX pins (RB5, RB6, RB7) are connected to a thermistor based temperature sensing circuit.

This should be a lot of fun.


Thanks Bean!

- Sparks

Bean

Here is the file that was sent...

There is 4 of each design on each board.·So you will be receiving 12 boards of each design.

Bean.
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Bean

Here is my 8 Pin DIP prototype and the code to make it into a 3 channel PWM controller.
It is controlled using pulse widths.

The parts are 0603 size. Kinda tough to place them without solder mask. And I MUST remember to NOT fill in the area when there is no solder mask.

Bean

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Post Edited (Bean (Hitt Consulting)) : 12/19/2007 12:24:49 PM GMT