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More and better information about hardware revisions

Posted: Thu Aug 15, 2019 10:12 am
by start78
Not long after the Pi4 was out there have been reports that certain USB-cables won't work for powering the Pi4. That has been confirmed by Eben Upton and he talked about a possible board revision fixing it. He never promissed that fix and i now strongly doubt the arrival of that board revision will ever be officially announced.

That reminds me of the focus problems with the first patch of the Raspberry Pi Cam V2. At one point in the discussion Eben Upton talked about changing the glue that fixes the lense with some sort of "viscous compound". Never happened as far as i am informed.

There have been very few really annoying bugs in the history of Raspberry Pi hardware. And the one that was handeled best imho was the power problem with the POE HAT.

For the possible Pi4 board revision: Will there be any way to distinguish the different versions?

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 10:27 am
by davidcoton
start78 wrote: Will there be any way to distinguish the different versions?
Of course there will. At the very least the new component will be visible, if you know where to look.
I would assume that a new board layout (to accommodate the resistor and any other hardware mods made at the same time) will result in a new point version number on the PCB, as has happened with previous revisions.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 1:34 pm
by bensimmo
On the PCB as in v1.1, v1.2 etc.?

That didn't happen when the A+ gained an extra 256MB or the Pi2 changed to a different generation of SoC or the Pi3B moved to a new revision of the SoC.
My bad it did, didn't it? Pi2 v1.1 and v1.2
I've not seen the 3B with the newer SoC other than in pictures, I think that moved to 1.3, again a large change using the B0 SoC.
But that is quite a change, a resistor is not.

And they've not altered as components have been reduced on the boards.

The only ones have been the original B and then once the B+ was established it would have been the Zero as it gained a camera connector.

I think.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 1:52 pm
by rpdom
The ones without revision number changes are ones where the PCB wasn't changed.

Upgrading the RAM on the A+ didn't need a board change, so no point in setting up a new set of files just for a minor silkscreen change.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 4:24 pm
by davidcoton
rpdom wrote:
Thu Aug 15, 2019 1:52 pm
The ones without revision number changes are ones where the PCB wasn't changed.

Upgrading the RAM on the A+ didn't need a board change, so no point in setting up a new set of files just for a minor silkscreen change.
Exactly this. If the board changes, it gets a new revision number. If the board is unchanged (e.g., remove a component, add one to a previously unpopulated position, change to a pin-compatible alternative), then the board revision is unchanged. Normal engineering practise is that the board revision refers to the track layout, there may also be a module revision for the populated board but that won't be on the silkscreen -- just a sticker or an assembly overprint.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 5:16 pm
by W. H. Heydt
davidcoton wrote:
Thu Aug 15, 2019 10:27 am
I would assume that a new board layout (to accommodate the resistor and any other hardware mods made at the same time) will result in a new point version number on the PCB, as has happened with previous revisions.
While you may be correct, I note that the current Pi4B doesn't have a version number on the PCB. So *if* they include a "new" version number and it is silk-screened onto the board, the mere presence of such a number will be a distinguishing characteristic.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 5:25 pm
by W. H. Heydt
bensimmo wrote:
Thu Aug 15, 2019 1:34 pm
On the PCB as in v1.1, v1.2 etc.?

That didn't happen when the A+ gained an extra 256MB or the Pi2 changed to a different generation of SoC or the Pi3B moved to a new revision of the SoC.
My bad it did, didn't it? Pi2 v1.1 and v1.2
The shift from the Pi2Bv1.1 to Pi2Bv1.2 was probably the biggest change never to be announced. Word got out when people noticed the different SoC on the board (BCM2836 to BCM2837).
I've not seen the 3B with the newer SoC other than in pictures, I think that moved to 1.3, again a large change using the B0 SoC.
But that is quite a change, a resistor is not.
Has the Pi3B shifted to using the B0 stepping? The only practical reason to do that that I can think of would be to reduce inventory (one less part to stock), but that wouldn't happen unless the Pi2Bv1.2 also shifted to the B0 stepping...which--I think--would be noticed pretty quickly.

Adding another resistor may require track changes. Minor as that is, it would mean a new revision number. Whether the number makes it onto the board were we can set it is anybody's guess.
The only ones have been the original B and then once the B+ was established it would have been the Zero as it gained a camera connector.
The original Model B went through several revisions, with varying amounts of announcement being made. I have versions...with 70mA polyfuses for the USB ports, with zero ohm resistors in place of the polyfuses, and with nothing there at all (that's the Model B v2.0).

The addition of the camera connector to the Pi0 was announced.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 5:36 pm
by trejan
W. H. Heydt wrote:
Thu Aug 15, 2019 5:25 pm
Has the Pi3B shifted to using the B0 stepping?
Yes. https://www.raspberrypi.org/app/uploads ... 3B-001.pdf
W. H. Heydt wrote:
Thu Aug 15, 2019 5:25 pm
Adding another resistor may require track changes. Minor as that is, it would mean a new revision number. Whether the number makes it onto the board were we can set it is anybody's guess.
Splitting the CC1 + CC2 lines and adding the resistor definitely needs a PCB change. There isn't any easy way of splitting the two lines except for lifting one of the legs on the USB-C socket.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 5:40 pm
by W. H. Heydt
trejan wrote:
Thu Aug 15, 2019 5:36 pm
W. H. Heydt wrote:
Thu Aug 15, 2019 5:25 pm
Has the Pi3B shifted to using the B0 stepping?
Yes. https://www.raspberrypi.org/app/uploads ... 3B-001.pdf
I guess I need to get a couple more Pi3B boards....

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 7:41 pm
by webbsmurfen
Okay..

My Raspberry Pi 4B 4Gb is in version 1.1 for some reason. Anybody own a RPI version 1.0

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 7:45 pm
by trejan
webbsmurfen wrote:
Thu Aug 15, 2019 7:41 pm
My Raspberry Pi 4B 4Gb is in version 1.1 for some reason. Anybody own a RPI version 1.0
The public release of the RPi 4B was v1.1. Any v1.0 board will have been for internal testing.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 7:59 pm
by W. H. Heydt
webbsmurfen wrote:
Thu Aug 15, 2019 7:41 pm
Okay..

My Raspberry Pi 4B 4Gb is in version 1.1 for some reason. Anybody own a RPI version 1.0
Where are you seeing the version number?

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 8:05 pm
by trejan
W. H. Heydt wrote:
Thu Aug 15, 2019 7:59 pm
Where are you seeing the version number?

Code: Select all

$ cat /sys/firmware/devicetree/base/model 
Raspberry Pi 4 Model B Rev 1.1

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 10:05 pm
by W. H. Heydt
trejan wrote:
Thu Aug 15, 2019 8:05 pm
W. H. Heydt wrote:
Thu Aug 15, 2019 7:59 pm
Where are you seeing the version number?

Code: Select all

$ cat /sys/firmware/devicetree/base/model 
Raspberry Pi 4 Model B Rev 1.1
So you're *not* seeing it on the board.

Re: More and better information about hardware revisions

Posted: Thu Aug 15, 2019 10:14 pm
by trejan
W. H. Heydt wrote:
Thu Aug 15, 2019 10:05 pm
So you're *not* seeing it on the board.
Yeah. It is only inside the firmware. The board doesn't have it at all.