contents of micro:bit reference design: web and repo

[OwenBrotherwood]

From my analysis.

1. https://github.com/microbit-foundation/microbit-reference-design/tree/master/Altium

• should contain the master of the schematic design
• the ascii export, let us call it "ACCEL ASCII" should be included
• it is questionable if any Altium binary blobs for schematics give any meaning in the git repro
• it is questionable if Altium binary blobs for pcb give any meaning in the git repro

2. Concentrate on ensuring the schematic is correct

• remove all pcb designs until this is met and the web should only give a general idea of possibilities with perhaps the main goal of true shareability of schematic design to ensure pcb IRL.

3. Others like Eagle etc etc (the list is endless)

• document import for the interesting list of schematic/pcb sw
• ensure that the import works with active community support for checking
• "if it doesn't work, issue it" and concentrate on issues from people who are actually using the schematic/pcb sw instead of a broad range of possible sw users.

The above are just a few of my thoughts, dependant on feedback to 1 2 3 this issue may come into other areas.

[sjwiseman]

1. I think that the Altium binary blob should stay. It's the source, like it or not. Everything else is derived.
   Yes, any useful derived intermediate files should be published. I didn't think the Accel was particularly useful. (It's also not something that I can generate automatically from the outjob.)
2. Not at all convinced by this. The PCB is (imho) an important part of the design. If people want to generate derivative works rather than starting from scratch, it'll save a few days. It's also something to swipe footprints from).
3. Yes! Import was surprisingly flaky and unsatisfactory. Given the maker movement's reliance on reuse, I'm surprised just how hard / bad it was. Obviously I'm spoilt with Altium's generally competent importers.
   I'm partly assuming that I'm doing it wrong(tm), and am hoping for assistance from seasoned users of those packages.
   I'm somewhat busy at the moment, but will watch, and do what I can. Shout if there's anything in particular.

[OwenBrotherwood]

1: Jep: let the blob be in: but never without a commit without the ASCII as documentation for change.
2: Jep: I am basically wanting more concentration on the sch to ensure 100% correct. I am not sure if anyone has actually used the pcb and tested: but I am sure someone will say something.
3: only with a little help from our friends, will the effort come forward: I do stuff as a total amatour and in many ways this gives a good result, relying on open mind and stubbornness.

At the present time: no immediate need for work by @sjwiseman : the documentation of how to export from Altium and import into a subset of interesting sw products is up to the community.

---

My current need for what I believe is "footprints", is the bottom connection layout on the micro:bit, otherwise I will have to do by hand :(

[OwenBrotherwood]

Export possibilities that are a available at the moment for upverter.com

• with due deference to Altium as source but possible way to another collaboration source with high attention to export to other tools

https://upverter.com/acornway/f52fb058b10f0566/acornway-reference-design/#design-exports

https://github.com/upverter/schematic-file-converter

https://forum.upverter.com/t/documentation-for-open-json-format/154

https://forum.upverter.com/t/import-from-altium-designer/149/2

[OwenBrotherwood]

[sjwiseman]

Ah yes, I remember - rotated components all over the place!
Do you want to raise a ticket with Upverter?

[OwenBrotherwood]

I think we wait a bit: I would prefer to break the diag. into smaller sections.
I am not sure of the terminology but there should be a way.
For programmers, reading all these lines of code (lines/pin nr etc) is hard: prefer to break into sections from start and reuse with no pain.

---

Edit: if a diagram has a problem, then it can be easier to finde a fix with smaller sections

[sjwiseman]

You're welcome to break the design apart, and stitch it all back together with hierarchy - but on a design this small and interconnected, I personally like to have it all visible.
(I suspect that hierarchy will also open a whole new can of worms when it comes to transferring between packages!)

[OwenBrotherwood]

I concentrate on learning more import/export and the copper pattern of the edge connector.
Modular ref design could give "something", but as stated: could get wormy

[OwenBrotherwood]

And seeing what footprints to swipe: but really missing the connector and edge copper

The PCB is (imho) an important part of the design. If people want to generate derivative works rather than starting from scratch, it'll save a few days. It's also something to swipe footprints from).

[sjwiseman]

On 9 January 2017 at 10:04, Owen Brotherwood ***@***.***> wrote: And seeing what footprints to swipe: but really missing the connector and

edge copper It's a Modulebit, not a Microtbit(tm). Designed to plug into breadboards, designed to be a start point for your own project. If you want a Microbit, I'd strongly suggest you buy one! You'll also note it's bigger, to give you some area on the PCB to build stuff, without interfering with the basic functionality - just blow away the audio section, and you have a decent amount of space. No-fit the audio and the battery, and you've (just!) got enough space for a little breadboard to stick on, then jumper wire to the 0.1" connections. Or do something else, that's kinda the point :) I wasn't just cloning the Microbit.

[OwenBrotherwood]

Or a baggybit
https://github.com/microbit-drill/baggybit :)
Rapidly having a Pi 40 pin interface to pi accessories
with SD flash and i2c extra io or capacitive touch and audio: if enough area
Keeping the present micro:bit v1 and hoping for more ram/flash in v2 and the edge copper on the back of the micro:bit having some i2c extras for i/o :)

[OwenBrotherwood]

Found a nice verified Nordic nRF51822-QFAA with pcb
May not quite be a Nordic nRF51822-QFAA-R rev 3 as in tech.microbit.org but I hope it is good enough
https://upverter.com/acornway/9b6866459a4eb097/microbit-raspberry-pi-and-mbed-pins/

I search for other ref design components

[OwenBrotherwood]

@sjwiseman @jaustin
#7 (comment) contains the first module of the mega:bit modular system.

[OwenBrotherwood]

@sjwiseman I found out today that the ic on the ref diagram is not an ic for nRF51822 but a module, as you may have hinted at earlier in the thread (I didn't get the hint :) ).
https://upverter.com/acornway/150e8cc130b43e8d/megabit-Ratac-MDBT40-nRF51822-Module/ is done I think
https://upverter.com/acornway/65697ed30d7e35d3/megabit-nRF51822-QFAA-Module/ will document the implementation of the Ratac module

---

I have done some successfull imports of Eagle today: but Altium sch and pcb from this repro still does not work