A DIY servo 'wire-wrap' board

Post Reply
Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

A DIY servo 'wire-wrap' board

Post by Richard-TX » 12.12.2013, 13:33

Here is the latest from the bench,

The wiring between the RJ45 jacks and controller is not done. There is enough room on the header pins to wire-wrap the wires on. Wire-wrap is nice as it is quick and easy.

Image

Total cost for the board which includes the $15 Adafruit controller is $16.50

rjversluis
Site Admin
Posts: 42044
Joined: 10.04.2006, 08:48
Location: Speyer, Germany
Contact:

Post by rjversluis » 12.12.2013, 13:48

Why not using/buying the GCA-Pi03?
If everyone copies and publish the Pi03 the complete production costs will hang at Peter which is a private investment... (About 200 Euro.)
::roll:
You do not have the required permissions to view the files attached to this post.

rjversluis
Site Admin
Posts: 42044
Joined: 10.04.2006, 08:48
Location: Speyer, Germany
Contact:

Post by rjversluis » 12.12.2013, 15:17

"wire-wrap"... Hard to believe you did post that...

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 12.12.2013, 16:00

Old school still works.

I have the wire wrap stuff here including a wrapping gun so I am using it. Welcome to the 1980's :D

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 12.12.2013, 16:59

rjversluis wrote:Why not using/buying the GCA-Pi03?
Peter's board does not meet my requirements. I think I mentioned this before. Here is why.

The RJ-11 6P6C connector is an odd one here. RJ45 is everywhere. Just buying 6 conductor cable requires a 50 mile round trip journey for me. The other option is to order it and have it shipped. Cat6 and RJ45 plugs are at the hardware store 2 miles away. Patch cables are too. Cat6 is what most people recommend for I2C due to it's low capacitance per ft./meter. In addition 6 conductor phone cable here is usually flat cable which means it is unsuitable for I2C FM+ (Fast Mode Plus) speeds. I have tried, It does not work.

If Peter's board had provisions for RJ45 sockets and would adopt a wiring scheme similar to what I posted so that 568A or 568B patch cables can be used, I would buy several and scragp everything that I have. On the plus side I think that RJ-11 plugs will work in a RJ45 jack.

I am sorry if this is upsetting. If want to, erase the thread. No hard feelings if you do. I won't be upset or mad.

If Peter changes the board, put me down for 20 pcs. That should keep me happy for a while.

Richard

rjversluis
Site Admin
Posts: 42044
Joined: 10.04.2006, 08:48
Location: Speyer, Germany
Contact:

Post by rjversluis » 12.12.2013, 17:03

Richard-TX wrote:The RJ-11 6P6C connector is an odd one here. RJ45 is everywhere.
Problems reading the WikI?
All GCA-Pi boards can be used with RJ11 or RJ45.

http://wiki.rocrail.net/doku.php?id=gca ... escription
Connection between these boards are either RJ12 cable or RJ45 Ethernet, just by selection of the right connector.

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 12.12.2013, 17:18

The wiki article is for the pi-01 so I assumed that that statement did not apply to the pi03

There are no board drawings for the Pi-03 otherwise I would have checked that.

I don't agree with the RJ wiring scheme but that issue can be resolved. The SDA and SCL signal lines should be twisted pairs with ground. +5 and +3 should be available or be sourced via the RJ45 too.
Last edited by Richard-TX on 12.12.2013, 17:27, edited 1 time in total.

rjversluis
Site Admin
Posts: 42044
Joined: 10.04.2006, 08:48
Location: Speyer, Germany
Contact:

Post by rjversluis » 12.12.2013, 17:26

Richard-TX wrote:The wiki article is for the pi-01 so I assumed that that statement did not apply to the pi03
That would be inconsequent... A RJ45 socket on the Pi01 and no support for a RJ45 socket on the Pi03!?

On the GCA-Pi boards a I2C line driver is added to make it unnecessary to use special cables or schemes.

You can rely on Peter's designs; He is a professional.
I don't agree with the RJ wiring scheme
Well, just cook your own soup and keep it for you.

(Last comment in this thread from my side.)

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 12.12.2013, 17:34

Logically you are correct, but I have learned to never assume anything.

Call it a fault.

As far as the wiring goes, I am going to change what he has. My own tests have shown that the signal lines should be a twisted pair with ground or with VSS.

I will be emailing Peter for a quote for some boards.

Richard

rjversluis
Site Admin
Posts: 42044
Joined: 10.04.2006, 08:48
Location: Speyer, Germany
Contact:

Post by rjversluis » 12.12.2013, 17:53

BTW: RJ11/12 is what USA's Digitrax/Loconet is using and Lenz in Europe.

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 13.12.2013, 19:47

rjversluis wrote:BTW: RJ11/12 is what USA's Digitrax/Loconet is using and Lenz in Europe.
That is true. I have some Loconet stuff. I had to drive almost 70 miles round trip to get them and a set of crimper dies to install the connectors.

Crimper dies? Yes, That AMP crimper is one of those heavy duty industrial grade crimpers. It has proven to be one of the better tools investments I have made.

Image

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 15.12.2013, 08:04

Rob,

I am curious. Why were you surprised by wirewrap? Wirewrap is pretty good for certain things. Wirewrap used to be the de facto standard for prototyping or small production boards.

The first Mac was done in wirewrap.
http://www.digibarn.com/collections/par ... ap5-board/

I don't do everything in wirewrap. Wirewrap sockets are too bulky. A regular socket or even a DIP pin works fine for a single connection. Works great for headers. For connecting a resistor to a led, it is quicker and easier than soldering.

Richard-TX
Posts: 1320
Joined: 10.07.2012, 04:00
Location: Texas, USA
Contact:

Post by Richard-TX » 15.12.2013, 08:52

I am ordering 20 boards with connectors from Peter. It is easier and cheaper that way.

Post Reply

Return to “DIY Hardware”