The Raspberry Pi Model B+ Q&A thread

[redhawk]

One of the launch videos does show a Raspi break out board mating to the new header without issue

What's the URL for the launch video??

Richard S.

[RaTTuS]

http://www.raspberrypi.org/blog/#introd ... del-b-plus

[jdb]

I've also noticed the presence of inductors and MOSFETs around the micro USB port, am I to understand that the LDOs have been replaced with switching bucks??

Is back feeding the USB port still safe with this board??

Richard S.

VBus now passes through the USB power switch. It is impossible to power up a B+ via backfeed, but reverse current (up to the reverse trip point of the power switch) on a powered-on B+ will pass through.

This is one of the reasons that there is now an "Ideal Diode" on the 5V input to the Pi. It's an exercise for the reader to figure out how it works.

http://docs-europe.electrocomponents.co ... 2faa1d.pdf

[fruitoftheloom]

http://www.linuxvoice.com/raspberry-pi-model-b

[jamesh]

One of the launch videos does show a Raspi break out board mating to the new header without issue

What's the URL for the launch video??

Richard S.

They are all linked from the launch blog post.

[arm2]

A lot of very useful improvements. Thank You RPF!
I can't see any pads for a reset switch, am I being blind?
I can see two pads marked 'RUN' what does it do?

[texy]

According to the CPC website the GPIO pins have been extended from 26 to 40 it also claims that it's backwards compatible with existing 26 pin projects.
This is actually wrong since a 26 pin connector will not be able to sit on a 40 pin GPIO due to the housing hitting pins 27 and 28.
Richard S.

That may well be true when talking about ribbon cable connectors, but not for fixed (pcb) mounted connectors. So if the additional hardware is ribbon cable connected, there may well be a problem, but for 'shield' type direction connection, it should be OK.
Texy

[jdb]

A lot of very useful improvements. Thank You RPF!
I can't see any pads for a reset switch, am I being blind?
I can see two pads marked 'RUN' what does it do?

The RUN header is the same as P6 on the Model B, it's just been moved next to the PWR/ACT LEDS (top left).

[jdb]

What is the board revision number as reported by /proc/cpuinfo ? Is there a complete list somewhere of all revision numbers that have ever been used?

I need this to update the RPi.GPIO module!

Board revision for the B+ is 0x10.

[0xFF]

Can model B+ be powered directly from 40 pin header's 5V rail ?

[ShiftPlusOne]

Can model B+ be powered directly from 40 pin header's 5V rail ?

GPIO, yes. But not USB.

[jdb]

Can model B+ be powered directly from 40 pin header's 5V rail ?

Yes. The 5V connection point is *after* the input diode.

For add-on board manufacturers that want to power the Pi this way, it is strongly recommended to add a duplicate of the input diode circuit between the power source and the 5V pin supplying the Pi.

USB Backpower is now not possible, as described previously.

[joan]

Can model B+ be powered directly from 40 pin header's 5V rail ?

GPIO, yes. But not USB.

Will the CPUs work?

[jdb]

Bonus feature: flip a B+ over. It's covered in test points (that you can void your warranty soldering to).

[SteveSpencer]

Since we are now told not to use ID_SD and ID_SC, presumably things that used P5 connections will no longer work, or will stop working at some point when the firmware changes to support the ID EEPROM mechanism?

I'm hoping that more details of this will be forthcoming soon, and I'm even more hopeful that RS genuinely do have stock so they can ship my order to arrive tomorrow as promised -- the joy of being an account customer.

[ame]

Does the new board have the capability to turn itself off (i.e. sudo shutdown -h now turns off power)? Or must we have an external switch?

[joan]

Since we are now told not to use ID_SD and ID_SC, presumably things that used P5 connections will no longer work, or will stop working at some point when the firmware changes to support the ID EEPROM mechanism?

I'm hoping that more details of this will be forthcoming soon, and I'm even more hopeful that RS genuinely do have stock so they can ship my order to arrive tomorrow as promised -- the joy of being an account customer.

I've had a dispatch notification and a Parcelforce tracking number from RS.

[arm2]

A lot of very useful improvements. Thank You RPF!
I can't see any pads for a reset switch, am I being blind?
I can see two pads marked 'RUN' what does it do?

The RUN header is the same as P6 on the Model B, it's just been moved next to the PWR/ACT LEDS (top left).

For those people like me who need it spelled out. P6 is the reset header! I wonder why the call it 'RUN' now?

[SteveSpencer]

I don't have a parcelforce notification, but it does say dispatched for my order

[ShiftPlusOne]

Can model B+ be powered directly from 40 pin header's 5V rail ?

GPIO, yes. But not USB.

Will the CPUs work?

Not sure what you mean, but I'm going to go with 'yes'. =)

[fruitoftheloom]

Since we are now told not to use ID_SD and ID_SC, presumably things that used P5 connections will no longer work, or will stop working at some point when the firmware changes to support the ID EEPROM mechanism?

I'm hoping that more details of this will be forthcoming soon, and I'm even more hopeful that RS genuinely do have stock so they can ship my order to arrive tomorrow as promised -- the joy of being an account customer.

I've had a dispatch notification and a Parcelforce tracking number from RS.

+1 hopefully receive tomorrow as have no Pi, as a relation has borrowed for school project !

[arm2]

Any Idea when the schematics will be released?
The Adafruit write up https://learn.adafruit.com/introducing- ... b?view=all includes quite a few parts of the B+'s schematic!

[joan]

...
Not sure what you mean, but I'm going to go with 'yes'. =)

I'm trying to find out what works if you supply power via the P1 header.

Yes, GPIO and CPUs.
No, USB.

Will everything else work, Ethernet, HDMI, audio, composite video, i,e, is it just the USB ports which won't work if you power via P1 rather than the microUSB?

[jdb]

Since we are now told not to use ID_SD and ID_SC, presumably things that used P5 connections will no longer work, or will stop working at some point when the firmware changes to support the ID EEPROM mechanism?

The board ID is different between B and B+. This will be used to differentiate whether the EEPROM gets probed or not. Firmware updates will be compatible across the revisions.

[jamesh]

...
Not sure what you mean, but I'm going to go with 'yes'. =)

I'm trying to find out what works if you supply power via the P1 header.

Yes, GPIO and CPUs.
No, USB.

Will everything else work, Ethernet, HDMI, audio, composite video, i,e, is it just the USB ports which won't work if you power via P1 rather than the microUSB?

Everything should work - that post was referring the power INPUT, not what is powered on. So you can still power up the device using GPIO, but not by backpowering via USB.