[TriEmbed] Favourite electrical connectors?

[Carl Nobile]

Pete,

What Charlie is trying to do is create a board that the people working on
the CANInstall spec can use as a base line tool. We won't be using long
cables for this initial work.

I like the RJ11 for some things, but it needs to mate with a flat cable
which by its nature can't be twisted, CAT cables won't mate to it without a
lot of extra work. We need, as Charlie just told me, four wires, two for
the CAN protocol and two for power. Each one will go to some sort of sensor.

~Carl


On Fri, Sep 25, 2015 at 12:46 PM, Pete Soper via TriEmbed <
triembed at triembed.org> wrote:

> The cable requirement for CANBUS is explicitly dictated by the bus
> standard (covered in this TI blurb
> <http://www.ti.com/lit/an/slla270/slla270.pdf>): you'll be using 120 ohm
> twisted pair. Accommodating the 120 ohm termination resistors needed at the
> two ends of the bus is a side issue that might interact with connector
> choice. The easy choice for cable is UTP (aka CAT3/5/6) with as few twisted
> pairs as you can get by with (since canbus only uses one pair). Somebody
> recently gave away hundreds of feet of this stuff at a TriEmbed meeting, so
> I think this is a good choice.
>
> The bus is only two wires, plus one more for an optional shield. So a very
> simple connector will do it. IMO the lowly RJ11 will get the job done. I
> have three crimping tools you can borrow. :-) The male connectors are cheap
> as dirt. Here's a Digikey jack
> <http://www.digikey.com/product-detail/en/A-2014-0-4-R/AE10390-ND/2183641>
> (35 cents at Q50). Some of the "big boys" use RJ45, but I can't see the
> need for that and it's just extra cost wrt PCB area.
>
> The lowly RJ11 combined with UTP cable might be a practical solution. The
> connector is "keyed", trivial to get in and out, but stays in place. You
> could also arrange a convention where a termination resistor could either
> be crimped into two additional connector sites (so the termination is part
> of the cable) or handled on the PCB. A weather boot would be used for cases
> where crud might get inside the connector, as it is highly exposed. Using
> dielectric grease to exclude oxygen would be a good idea too for cases
> where the connection is going to be exposed.
>
> -Pete
>
>
> On 09/25/2015 10:18 AM, Charles West via TriEmbed wrote:
>
> Hello,
>
> I'm working on a board for the CanInstall autoregistration project and I'm
> not really sure what connectors to use for it.  I'm currently leaning
> toward either DF13-4 connectors or simple 4 pin headers.  If I may ask, are
> there any other connectors that you would recommend or have used in your
> projects?
>
> Pros/cons:
> DF13:
> The upside is that they are very small, connect very securely and SMD
> female connectors are $.41 per.  The downside is that they are extremely
> hard to get out (don't pull on cable, very gently pry with finger nail on
> one side, then the other) and cables for them are extremely hard to
> find/expensive ($1.5 per in lots of 20 is the cheapest I've found).
>
> Vertical Headers:
> The plus is I can get break apart SMD headers at roughly $.05 each
> including shipping at lots of $5 (
> <http://www.ebay.com/itm/10pcs-2-54MM-1-40Pin-SMD-SMT-1-40Pin-Male-Single-Row-Pin-Header-/261879748701?hash=item3cf93fd85d>
> http://www.ebay.com/itm/10pcs-2-54MM-1-40Pin-SMD-SMT-1-40Pin-Male-Single-Row-Pin-Header-/261879748701?hash=item3cf93fd85d),
> cables at $.22 per in lots of $5 (
> http://www.ebay.com/itm/20pcs-2-54mm-to-2-54mm-Dupont-Wire-Cable-Connectors-4P-to-4P-Pin-Header-20cm-YG-/111487505711?hash=item19f52c552f)
> and they are pretty standard for hobbyist projects (and extremely similar
> to servo connections).  The downsides are that they have no polarity
> control, are much more likely to slide out and take up a lot more board
> real estate (translating to either bigger boards or less connectors).
>
> Thanks,
> Charlie
>
>
> _______________________________________________
> Triangle, NC Embedded Computing mailing listTriEmbed at triembed.orghttp://mail.triembed.org/mailman/listinfo/triembed_triembed.org
> TriEmbed web site: http://TriEmbed.org
>
>
>
> _______________________________________________
> Triangle, NC Embedded Computing mailing list
> TriEmbed at triembed.org
> http://mail.triembed.org/mailman/listinfo/triembed_triembed.org
> TriEmbed web site: http://TriEmbed.org
>
>


-- 
-------------------------------------------------------------------------------
Carl J. Nobile (Software Engineer)
carl.nobile at gmail.com
-------------------------------------------------------------------------------
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.triembed.org/pipermail/triembed_triembed.org/attachments/20150925/c30e33ec/attachment.htm>