PYBD WBUS connector

The official PYBD running MicroPython, and its accessories.
Target audience: Users with a PYBD
User avatar
pythoncoder
Posts: 4164
Joined: Fri Jul 18, 2014 8:01 am
Location: UK
Contact:

Re: PYBD WBUS connector

Post by pythoncoder » Fri May 08, 2020 6:48 am

The Pyboard D schematics show pin numbers from 1 to 40.
Peter Hinch

kesterlester
Posts: 10
Joined: Sat Nov 17, 2018 10:04 pm

Re: PYBD WBUS connector

Post by kesterlester » Fri May 08, 2020 1:56 pm

Attached is mashed-together image where I overlaid a pyboard D (both sides semi transparent) onto a 50mil grid to help me better visualise where the WBUS connectors are relative to other things on the board. I couldn't find something similar pre-existing. This is just done by eye, so take it with a pinch of salt. It is not definitive. Perhaps others will find it useful.

Notes:
  • I have only drawn the central 40 pins of each WBUS connectors, not the two extra mystery (mechanical/electrical/redundant?) connectors that are sometimes seen as an extra pair of pins at each end of the connector.
  • The WBUS pins are drawn with metric 0.4mm pitch, meaning that the y-value of the uppermost pin on either connector is 0.4mm*(19/2) = 3.8mm ..... which in is about 2.992 squares on my 50 mil grid -- which is why they appear to line up with a gridline, even though they don't. (3x50mil is 3.81mm).
Pyboard D native v blurry.jpg
Pyboard D native v blurry.jpg (159.69 KiB) Viewed 237 times

User avatar
tve
Posts: 200
Joined: Wed Jan 01, 2020 10:12 pm
Location: Santa Barbara, CA
Contact:

Re: PYBD WBUS connector

Post by tve » Fri May 08, 2020 4:08 pm

pythoncoder wrote:
Fri May 08, 2020 6:48 am
The Pyboard D schematics show pin numbers from 1 to 40.
Plus pins 81, 82, 83, 84! I counted the contacts on my PYBD and there are definitely 44 contacts in that connector.
Screenshot from 2020-05-08 09-05-47.png
Screenshot from 2020-05-08 09-05-47.png (112.28 KiB) Viewed 231 times

User avatar
dhylands
Posts: 3359
Joined: Mon Jan 06, 2014 6:08 pm
Location: Peachland, BC, Canada
Contact:

Re: PYBD WBUS connector

Post by dhylands » Fri May 08, 2020 4:50 pm

There is a photo with some dimensions on it here:
https://store.micropython.org/media/pro ... F2_ds3.jpg

chuckbook
Posts: 115
Joined: Fri Oct 30, 2015 11:55 pm

Re: PYBD WBUS connector

Post by chuckbook » Sun May 10, 2020 3:10 pm

According to Hirose specs the four extra pins on the 40 pin connectors are only for mechanical stability. They can't be used as extra contacts.

User avatar
tve
Posts: 200
Joined: Wed Jan 01, 2020 10:12 pm
Location: Santa Barbara, CA
Contact:

Re: PYBD WBUS connector

Post by tve » Sun May 10, 2020 4:10 pm

chuckbook wrote:
Sun May 10, 2020 3:10 pm
According to Hirose specs the four extra pins on the 40 pin connectors are only for mechanical stability. They can't be used as extra contacts.
Can you provide a link to the "Hirose specs" you are looking at, and perhaps a pointer where to find that statement in the doc?

I'm looking at https://www.hirose.com/product/document ... =D31649_en and right at the top it shows a photo of a 40-pin connector and there are 40 contacts, unlike the 44 contacts visible on the PYBD. The document mentions the "style B" of the connector "with reinforcing metal fitting" and that adds 4 extra pads to solder the connector down to the board, but they are clearly separated from the rest of the 40 contacts, see page 4 "recommended PCB layout" right figure.

User avatar
tve
Posts: 200
Joined: Wed Jan 01, 2020 10:12 pm
Location: Santa Barbara, CA
Contact:

Re: PYBD WBUS connector

Post by tve » Sun May 10, 2020 4:29 pm

Ah, mystery solved after checking the measurements with a caliper: what's on the PYBD is the header, not the receptacle. Page 10 of the doc linked in the previous post applies. It has "Note 3 : Use the contacts at the four corners as metal fittings. Do not use them as signal or power contacts." So it's really a 44 contact header but the receptacle apparently only has 40 contacts (I don't have a daughter card to check) and the 4 corner contacts on the header are actually mechanically not fully accessible (some of the end plastic overlaps them a bit). Confusing stuff!

Post Reply