The Raspberry Pi Model B+ Q&A thread

[arm2]

The 5v to the HDMI socket is fed by an AP2331W current limiting device. This limits the maximum current to 400mA.
-Gordon

Thanks Gordon. How do you know that?
Have I missed the schematics being published?

[redhawk]

Just out of curiosity did the Model B+ go through the same rigorous EMC testing as the model B board??

I'm currently looking on the FCC website for the Raspberry Pi but can only find one set of reports filed under the ID "2ABCB-RPI21".

Richard S.

[jdb]

Just out of curiosity did the Model B+ go through the same rigorous EMC testing as the model B board??

I'm currently looking on the FCC website for the Raspberry Pi but can only find one set of reports filed under the ID "2ABCB-RPI21".

Richard S.

B+ went through the same level of EMC/compliance testing as the B. There's a considerable lag between reports being submitted to the FCC and them turning up on the website.

[gordon@drogon.net]

The 5v to the HDMI socket is fed by an AP2331W current limiting device. This limits the maximum current to 400mA.
-Gordon

Thanks Gordon. How do you know that?
Have I missed the schematics being published?

There's a small one-page update that was published - I think if you search the raspberrypi.org site in the documentation it has it there. It doesn't contain everything, but a few important and handy bits so-far.

found it:

http://www.raspberrypi.org/documentatio ... /README.md

-Gordon

[redhawk]

Is there an FCC ID report for the Model B+ when I search for Raspberry Pi I under "Applicant Name:" can only find "2ABCB-RPI21" - https://apps.fcc.gov/oetcf/eas/reports/ ... Search.cfm

Richard S.

[jdb]

Is there an FCC ID report for the Model B+ when I search for Raspberry Pi I under "Applicant Name:" can only find "2ABCB-RPI21" - https://apps.fcc.gov/oetcf/eas/reports/ ... Search.cfm

Richard S.

B+ went through the same level of EMC/compliance testing as the B. There's a considerable lag between reports being submitted to the FCC and them turning up on the website.

[redhawk]

Ah okay good point I guess the FCC are a bit slow with the paperwork.

Richard S.

[arm2]

The default current limit setting for the USB ports is 600mA (aggregate across the 4 ports). This can be increased to 1.2A via software config if you have a sufficiently powerful PSU.

How do you configure it in software?
start.elf?

[DirkS]

The default current limit setting for the USB ports is 600mA (aggregate across the 4 ports). This can be increased to 1.2A via software config if you have a sufficiently powerful PSU./quote]

How do you configure it in software?
start.elf?

See https://projects.drogon.net/testing-set ... erry-pi-b/

[gordon@drogon.net]

The default current limit setting for the USB ports is 600mA (aggregate across the 4 ports). This can be increased to 1.2A via software config if you have a sufficiently powerful PSU./quote]

How do you configure it in software?
start.elf?

See https://projects.drogon.net/testing-set ... erry-pi-b/

Or if you have wiringPi v2.20 (you'll need to do a pull as I've just done a checkin), then

Code: Select all

gpio usbp hi|lo

-Gordon

[plugwash]

One thing i've noticed with the B+ is that the act light comes on at power on, even if there is no SD card or a SD card without usable firmware. This was somewhat confusing at first (especially as I was testing firmware compatibility*) as on the previous models the ACT light illuminating indicates the firmware has been loaded successfully and the system is booting.

Was this a deliberate design descision or a side affect of some other change (I'm guessing the latter)

* others reported that old firmware booted but the USB didn't work but for me it didn't boot at all. Go figure.

[dom]

One thing i've noticed with the B+ is that the act light comes on at power on, even if there is no SD card or a SD card without usable firmware. This was somewhat confusing at first (especially as I was testing firmware compatibility*) as on the previous models the ACT light illuminating indicates the firmware has been loaded successfully and the system is booting.

Was this a deliberate design descision or a side affect of some other change (I'm guessing the latter)

The ACT led did change from active low on rev1/rev2 to active high on B+. I guess that is what caused this.
As this behaviour occurs without any software being run, it can't be changed.
I guess this need to be mentioned in the FAQs that ACT solidly on (on B+) means firmware couldn't be loaded at all (Working firmware will flicker for 20/30 seconds and then go off).

[mahjongg]

The ACT led did change from active low on rev1/rev2 to active high on B+. I guess that is what caused this.
As this behaviour occurs without any software being run, it can't be changed.
I guess this need to be mentioned in the FAQs that ACT solidly on (on B+) means firmware couldn't be loaded at all (Working firmware will flicker for 20/30 seconds and then go off).

I did add this new info to the boot problem stickies (which were completely overhauled for the B+).

[solar3000]

What's the new safe overclocking speed for the B+??

[dom]

What's the new safe overclocking speed for the B+??

There has never been any evidence of hardware damage through overclock, so any speed is safe.
Whether a specified overclock works for you or not is something specific to your pi (and power supply) and we can't answer that.

You'll have to try it and see. Start with a clean raspian install (or make a backup of sdcard first) and try the options from raspi-config.
If you get any unexplained crashes the try a lower option.

A combination of improved processes at the foundary and better the better power supply on the B+ means more people should achieve a high overclock than before, but there's no guarantee.

[RichShumaker]

I am cross posting as this is a B+ question as well.
I am working on a way to immediately start from B to B+ and the SD card is now a micro SD card(not directly swappable)
Original Post I made on another thread
http://www.raspberrypi.org/forums/viewt ... =63&t=1253

This idea started from the 16MB RasPi Post
http://www.raspberrypi.org/boot-from-a-16mb-sd-card/

I have purchased 128mb sd micro cards(cheapest I could find)
I have gotten my B+ to work with
1. 128mb Micro SD and a USB Flash Drive(Raspbian Image)
2. 128mb Micro SD and an SD Memory Card Reader with a Raspbian Image SD Card
3. Not Working - 128mb Micro SD and an SD Memory Card Reader with a NOOBs Image SD card

My question is how would you specify the boot location for a NOOBs configured RasPi SD card or is it not possible?
So far /sda2 has worked for #1 and #2 above even when I had to move the SD Reader as it was to big and blocked the Ethernet port.

Thanks for your help.

[FTrevorGowen]

...
My question is how would you specify the boot location for a NOOBs configured RasPi SD card or is it not possible?
...

Whilst I can't directly answer the above, wouldn't the fact that NOOBS has to re-size it's original partition** (on its card) and add in new ones also cause problems (ie. I think the /dev entries for the latter would be different too, but I could be wrong)?
Trev.
** after the very first boot, creating what becomes its recovery partition.

[edo1]

The 9514 hub's power control is hooked up to the USB power switch. Sending a control message via USB can power it off/on.

http://askubuntu.com/questions/149242/i ... rom-ubuntu

Are you sure?

I just tried it with:

Code: Select all

echo 0 > /sys/devices/platform/bcm2708_usb/buspower/

and its powered down the hub/ethernet chip but the 2 things (Pi's) I have plugged into the B+ USB sockets are still running.

you can use hub-ctrl to turn on/off power on USB ports:
http://www.gniibe.org/oitoite/ac-power- ... hub-ctrl.c

I checked it with B+ - it works!

[edo1]

was http://www.microchip.com/wwwproducts/De ... ct=LAN9512

now http://www.microchip.com/wwwproducts/De ... ct=LAN9514

there is 9514 on my B (without plus)

pi-b.jpg (60.83 KiB) Viewed 9309 times

But the same 9514 on B+ is colder, I don't know why.

[RaTTuS]

yes the 9514 is pin compatible replacement for 9513 and 9512
so all fit and work on a plain B
if there is a stortage they can be directly replaced
you could wire up 4 ports on that B if you have the eyesight and steadyness

[RichShumaker]

...
My question is how would you specify the boot location for a NOOBs configured RasPi SD card or is it not possible?
...

Whilst I can't directly answer the above, wouldn't the fact that NOOBS has to re-size it's original partition** (on its card) and add in new ones also cause problems (ie. I think the /dev entries for the latter would be different too, but I could be wrong)?
Trev.
** after the very first boot, creating what becomes its recovery partition.

I am beginning to think 'impossible' to use the MicroSD to NOOBs SD solution. I understood it wrote multiple images to the card, but I thought they might be standardized, so that way sda2/boot1 is Raspbian or something like that.
I read and re-read the forum last night. Lots of 'someone' 'someday' might come up with a solution posts.
Read more posts on how to leave NOOBs behind, and how to do that.

Guess I recommend BerryBoot V2 to boot multiple OS's from USB. Now I need to confirm that BerryBoot fits on a 128MB MicroSD and can install multiple OS's on USB.

Thanks everyone again for your help.

[AndrewS]

...
My question is how would you specify the boot location for a NOOBs configured RasPi SD card or is it not possible?
...

Whilst I can't directly answer the above, wouldn't the fact that NOOBS has to re-size it's original partition** (on its card) and add in new ones also cause problems (ie. I think the /dev entries for the latter would be different too, but I could be wrong)?
Trev.
** after the very first boot, creating what becomes its recovery partition.

I am beginning to think 'impossible' to use the MicroSD to NOOBs SD solution. I understood it wrote multiple images to the card, but I thought they might be standardized, so that way sda2/boot1 is Raspbian or something like that.

I've not tried it myself, but it should be perfectly possible. You just need to understand how NOOBS' partitioning works https://github.com/raspberrypi/noobs/wi ... -explained

So if you try setting the root partition to /dev/sda6 that should then work...
The OS-selection menu of NOOBS will never work on a USB stick (multiboot can only work from an SD card), so you'll need to copy the contents of /dev/sda5 on the NOOBS card to your 128MB SD card.

But at least in theory (it'd need quite a bit of config file-editing and partition-shuffling) I guess you could have each of the OSes boot partitions on the small internal MicroSD card, and then each of the OSes root partitions on the big external USB-connected SD card (since the cmdline.txt in each boot partition specifies the device for the root partition).

EDIT: You'd never be able to use this method to "reinstall" an OS using NOOBS, since it always attempts to recreate all the partitions itself.

[RichShumaker]

Thank you very much for your reply and help!!!

I will work on this later today and see what I can come up with.

[deaftolight]

Does anyone know where to place the heat sinks on the new B+ model? I ordered a new set of 3 heat sinks, but I can only see where two of them go on the B+ model.

Also, since the heat sink already have thermal adhesive attached, I was wondering if I was supposed to apply thermal paste, or if that would mess things up and make the heat sinks not stick.

Thanks!

[gkreidl]

Heat sinks are only needed by the companies that sell them to make money.