What are the other two USB ports for?

[Mark Fishman]

The B2 uses a Raspberry Pi 3 B+ board. While swapping out my SD card today I noticed (and confirmed via the web) that the RPi3B+ has four (4) USB2.0 ports on it. Two have cables plugged in, connected by short cable to the other (large) board, and thence presumably to the back panel USB ports. I understand that the hard disk uses a USB to SATA kind of interface, which is why there's no external "USB B" jack -- but there's a fourth port unaccounted for.

Is either of the "uncabled" USB ports on the motherboard available for use?

And then there's that microUSB port that comes out the back -- the Raspberry Pi folks say thats for loading the OS and transferring data (unspecified); presumably that's not something that we could make any use of? (yes, that's a question)

Inquiring minds, and all that -- thanks -- Mark F.

[PMB]

Hi Mark,

I've often wondered that myself. It appears there are two spare USB ports on the R Pi board as the HDD appears to connected somewhere else (haven't identified where yet). As the B2 recognises devices connected to USB A or USB C and displays these accordingly, I would assume some extra software would be needed....

The micro USB is used for power and a programming interface when using the R Pi in standalone mode - not sure it has any practical use on the B2.

The 3.5mm (unmarked) socket is audio and video out from the R Pi board - not sure if it is enabled or not.

Paul

Brennan Support.

[Peter Lowham]

Hi Guys,

The following information has been gathered during my SD card swapping and other activities on both an early model B2 (SD card late 2016) and a late model B2 (microSD card mid 2020).

My early model B2 uses the Ras-Pi 1 Model B v1.2 (c)2011 (stamped on the board).

My late model B2 uses the Ras-Pi 1 Model B+ v1.2 (c)2014 (stamped on the board).

The only notable differences between the two versions are:

The two models have a different physical layout of the hardware components so they cannot be swapped over.

The Model B has a 26 pin header plug to the daughter board, the Model B+ has a 40 pin header plug.

The Model B has 2 USB ports on board, the Model B has 4 USB ports.

Both  models use the same processor and run at the same speed and have 512MB of memory, so there is no performance difference between early and late model B2s..

I think that the reason for the change from early to late model B2s was probably that the Ras-Pi 1 Model B was being taken out of production by Raspberry and was replaced by the Ras-P1 1 Model B+.  This new model is sold @ $10USD cheaper than the old model (Model 1 B $35,  Model 1 B+ $25).

With regard to the Ras-Pi 3 B+, this has the same physical layout as the Ras-P1 1 Model B+ and will physically fit into the later model B2.  However, the Pi 3B+ runs on a different processor and uses a different instruction set, so the B2 software is not directly compatible wiith the P1 3B+.  I have tried this, but the B2 only presents the flashing green & red lights, just as it does if the microSD card is corrupt.  

I haven't done any checking of the two additional USB ports, mainly because I don't need them.  If I get some spare time, I'll have a look at this, but it won't be soon.

Regards,

Peter.