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P2 full datasheet badly wanted and needed — Parallax Forums

P2 full datasheet badly wanted and needed

Some of us have already invested a substantial amount of time and some (not so substantial) money in the P2.

The fact is there are many documents available on the P2 scattered over many places, some of it not so up to date.

I'm not complaining but expressing a strong and genuine desire to have a FULL P2 datasheet with all the information usually found in one.

Money come and go but time spent on searching for answers that should be found in a proper datasheet we will never be able to regain.

I am sure, I'm not the only one who misses that datasheet.
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Comments

  • I can second that. But I think there should be two data sheets versions.

    1. A short one for marketing listing all the features, the advantages over other µCs and the most important electrical characteristics. This one is really urgent, I think. It's bad for the P2 reputation if DigiKey lists the P2 with totally false specifications. Even the smallest and ugliest chinese shops have a link to a data sheet for every item they sell. If you can't provide a data sheet then nobody except the enthusiasts who are already here will buy it. The technical details can be left out.

    2. A verbose one for the developpers. At the beginning this could be a brushed up version of the already existent silicon, and smart pin documentation. The ultimate goal should be something like the documentation for the P1 which I like very much. There are examples for every instruction with detailed explanations of special cases and so on. I'm fully aware that this takes time...
  • bob_g4bbybob_g4bby Posts: 146
    edited 2020-12-24 15:09
    In the three electronics companies I worked in during my career, we had technical authors. They would come and interview us, as the hardware designers, during the time they wrote the user documentation for the new equipment. That way the documentation got written in time for the hardware launch, whilst the designers got on with what they were good at - designing.

    Some P2 users are finding gaps in the documentation. We presume Parallax are stretched and can't finish these right now. I wonder can we, the forum members, be more proactive and help produce that documentation ?

    Chip and Ken have found time to do the Early Adopter Series of presentations / discussions, which is great. The last one on A/D conversion was good.

    Is show-and-tell + pencilled drawings and sketches on a specific topic by Chip and other knowledgable people also the way to feed us 'volunteer technical authors' ? Just a suggestion - I would do some of this, if there's a few of us, so it would make a significant difference. But would it work with the detailed subject matter? As pointed out above - we've got the P1 document as framework and style guide and the 'P2 silicon' as a great jumping off point.

    1. Who else is able to help?
    2. What topics are most missed at present?
    3 Is the documentation currently being produced, just be patient for a bit longer or
    4. Does Parallax think this would work and is a 'P1 document' for P2 what's required?
  • I am fairly sure the only document that matters is this one:

    https://docs.google.com/document/d/1gn6oaT5Ib7CytvlZHacmrSbVBJsD9t_-kmvjd7nUR6o/edit#
  • Cluso99Cluso99 Posts: 17,470
    bob_g4bby wrote: »
    In the three electronics companies I worked in during my career, we had technical authors. They would come and interview us, as the hardware designers, during the time they wrote the user documentation for the new equipment. That way the documentation got written in time for the hardware launch, whilst the designers got on with what they were good at - designing.

    Some P2 users are finding gaps in the documentation. We presume Parallax are stretched and can't finish these right now. I wonder can we, the forum members, be more proactive and help produce that documentation ?

    Chip and Ken have found time to do the Early Adopter Series of presentations / discussions, which is great. The last one on A/D conversion was good.

    Is show-and-tell + pencilled drawings and sketches on a specific topic by Chip and other knowledgable people also the way to feed us 'volunteer technical authors' ? Just a suggestion - I would do some of this, if there's a few of us, so it would make a significant difference. But would it work with the detailed subject matter? As pointed out above - we've got the P1 document as framework and style guide and the 'P2 silicon' as a great jumping off point.

    1. Who else is able to help?
    2. What topics are most missed at present?
    3 Is the documentation currently being produced, just be patient for a bit longer or
    4. Does Parallax think this would work and is a 'P1 document' for P2 what's required?

    There have been many documents written by forum members over the years. Unfortunately they we’re outdated by the continual P2 design changes, and then we’re ignored by Parallax which left those authors disheartened.
  • The potential for errors in any 'user written' datasheet are substantial and could potentially harm the reputation of the P2. Does Parallax want to risk the possibility of errors in the documentation?

    In my opinion, the datasheets have to come from Parallax to have any value. If you have an IC and no instructions to allow people to put that IC to work, you don't have a complete product. Few will buy an incomplete product.
  • evanhevanh Posts: 10,425
    A datasheet, as opposed to a programming manual, won't be done until Chip has transitioned from developing. There will need to be testing of the environmental and behavioural limits. On Semi will provide much data but there'll be gaps that need filled.

  • RaymanRayman Posts: 11,842
    It took years (as I recall) for P1 to get a data sheet ...

    If I were doing it, I’d probably start from that...
  • pik33pik33 Posts: 942
    edited 2020-12-26 08:41
    What needs update is: to add - on the start of the manual:

    - recommended and maximum available CPU clock,
    - 1.8v current draw (vs cogs# and frequency) which I saw somewhere on the forum, then I didn't bookmark it and can't find it anymore,
    - critical voltages (min and max on 1.8V line, min and max on 3.3V lines, min and max on pins) and authorized answer for a question - "can I connect 5V logic to GPIO pins via 1 (10?) kOhm resistor? (or I cannot and it will fry the P2)"
  • cgraceycgracey Posts: 13,403
    edited 2020-12-26 11:03
    Agreed.

    I think we need these done:

    1) Electrical specs, including temperature vs. frequency performance
    2) Low-level smart pin specs

    Just working on the disassembler tonight for the single-step debugger.
  • I also see the documents beeing based on the knowledge you get if you know the P1 manual. Sometimes it is had to understand if you do not know P1 terms and names
  • Peter JakackiPeter Jakacki Posts: 10,043
    edited 2020-12-27 00:42
    Chip, before you get too bogged down in the tiny details can you just do the cover pages for it first much like I started to do with my unofficial shortform P2 datasheet wayback when. That way all the correct information regarding the features and pinout and package etc are there, then you have some breathing space to get all those min/typ/max/abs electrical specs together and fill in the other details. Bear in mind that there are datasheets and there are user manuals and there are programming manuals.

    Btw, the reason I created the datasheet in the first place was mainly so that I had a reference for hardware design. In the process of creating the datasheet I saw the need for a "typical circuit" which led to the P2D2 design (the very first P2 chip was assembled onto it as nothing else was available). The P2 chip pinout graphic was created to help make the P2 chip real, before we had silicon.

    You may have heard it bemoaned many many times on the forum, but all this volunteer work is such a huge waste of our time because Parallax doesn't leverage it or even acknowledge it. It is meant to help Parallax and to help you Chip.
  • cgraceycgracey Posts: 13,403
    Peter, that looks good. Do you have a link to the source material so that I could update it?

    I don't mean to drop the ball. There's just more than I can address, it seems. I don't want for these efforts to go unappreciated, of course, but I find it hard to work on these things.

    By the way, Jon Titus has written a nice paper on the smart pins, and I've proofed the first 20%, but there's more proofing needed. I've been meaning to ask on our Zoom meetings if anyone would like to pick up this effort, but I keep forgetting. I could share the document with anyone interested.
  • evanhevanh Posts: 10,425
    cgracey wrote: »
    By the way, Jon Titus has written a nice paper on the smart pins, and I've proofed the first 20%, but there's more proofing needed. I've been meaning to ask on our Zoom meetings if anyone would like to pick up this effort, but I keep forgetting. I could share the document with anyone interested.

    I'm up for that I think. Gaming with friends over the hols so not always around though.

  • Peter JakackiPeter Jakacki Posts: 10,043
    edited 2020-12-27 01:41
    All files are shared in my Tachyon Dropbox folder under P2 and docs etc.

    In the meantime I have saved the LibreOffice document to a docx format. There are other documents in their LibreDraw format but I don't know if MSO has an equivalent.
  • cgraceycgracey Posts: 13,403
    evanh wrote: »
    cgracey wrote: »
    By the way, Jon Titus has written a nice paper on the smart pins, and I've proofed the first 20%, but there's more proofing needed. I've been meaning to ask on our Zoom meetings if anyone would like to pick up this effort, but I keep forgetting. I could share the document with anyone interested.

    I'm up for that I think. Gaming with friends over the hols so not always around though.

    Thanks, Evanh. I just shared it with you. It's a Google Doc. Is that going to work for you?
  • cgraceycgracey Posts: 13,403
    All files are shared in my Tachyon Dropbox folder under P2 and docs etc.

    In the meantime I have saved the LibreOffice document to a docx format. There are other documents in their LibreDraw format but I don't know if MSO has an equivalent.

    Thank you, Peter. I've got it loaded and I can work on it now.
  • Hi Peter

    Libre Office 7.0.3.1 (x64) is overlapping the last two pages (5,6) of the .docx file you posted.

    Downloading last available stable version of it (7.0.4 (x64)), in order to confirm the issue has nothing to do with my side of things (it'll take a while due to my slow connection speed)...

    P2_Shortform_Last_Pages_Overlap_01.jpg
  • @Yanomani - thanks for the heads-up and I will check it but this part of an official datasheet doesn't need to be there either.
  • I think a good P2 manual is also needed, My P1 manual is quite thick.
  • @Yanomani - thanks for the heads-up and I will check it but this part of an official datasheet doesn't need to be there either.

    Fully agree with you!

    Initially I thought I was having a double-vision episode (uncommon with me, but, just in case), then, I've resorted to Irfanview, for a second opinion... :lol:
  • cgraceycgracey Posts: 13,403
    Yes, I noticed that things were layering on top of each other. Probably some problem with the format conversion.
  • I added the ppa for the latest LibreOffice version since LM20 uses 6.4 normally. But this is a new 1TB SSD on my laptop where I installed LM20.1beta so I may as well run betas on a beta. Opening the odt and saving in docx results in a slightly different file size but when I open it the text box is misaligned. However these text boxes are meant to be overlapping anyway and it was all left unfinished at the time.
  • evanhevanh Posts: 10,425
    Post the native ODT. M$ Word can open them.

  • They are all in the Dropbox folders, kitchen sink and all.
  • evanhevanh Posts: 10,425
    cgracey wrote: »
    Thanks, Evanh. I just shared it with you. It's a Google Doc. Is that going to work for you?
    Seems doable. The share provides an option to edit as visitor, account not required.

  • evanhevanh Posts: 10,425
    They are all in the Dropbox folders, kitchen sink and all.
    Ha, totally missed that link.

  • The lack of proper, quality docs, logically structured, all in one easy to access place is evident and spreads the frustrations across other threads, and rightly so.
  • cgraceycgracey Posts: 13,403
    Maciek wrote: »
    The lack of proper, quality docs, logically structured, all in one easy to access place is evident and spreads the frustrations across other threads, and rightly so.

    Understood.
  • We still don't have any electrical specs, have we. How much current can a pin drive?
    a) savely without too much voltage drop?
    b) absolute maximum rating without damaging the pin?
  • hinvhinv Posts: 1,033
    DigitalBob wrote: »
    I think a good P2 manual is also needed, My P1 manual is quite thick.

    Yes, exactly my P1 manual got thick with use and abuse. I loved that book. It was well written, especially the examples and tables. Having one online is just not the same. I would pay $50 for one if it was as well written as The Propeller Manual.
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