BMS Doug
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Re: Difference between B and B+

Wed Jul 30, 2014 1:47 pm

I had a very Monty Python feeling while reading this thread:
All right, but apart from the sanitation, medicine, education, wine, public order, irrigation, roads, the fresh water system and public health, what have the Romans ever done for us?
Doug.
Building Management Systems Engineer.

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mahjongg
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Re: Difference between B and B+

Wed Jul 30, 2014 7:07 pm

P.S. I learned the B+ has two hardware PWM engines, not just one:

source: http://www.raspi.today/the-making-of-th ... el-b-plus/

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AndrewS
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Re: Difference between B and B+

Wed Jul 30, 2014 7:25 pm

mahjongg wrote:P.S. I learned the B+ has two hardware PWM engines, not just one:
source: http://www.raspi.today/the-making-of-th ... el-b-plus/
Correct, PWM0 and PWM1 http://elinux.org/RPi_BCM2835_GPIOs
With PWM0 used for right analogue audio, and PWM1 used for leftt analogue audio 8-)

(the difference between the B and B+ in this regard is that Model B only has PWM0 available on the GPIO header, whereas Model B+ has both PWM0 and PWM1 available on the GPIO header)

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mahjongg
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Re: Difference between B and B+

Wed Jul 30, 2014 7:37 pm

so no analog sound and hardware PWM simultaneously, but that was already true for the B also (unless you cared for
mono audio).

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AndrewS
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Re: Difference between B and B+

Wed Jul 30, 2014 7:51 pm

Egzakkirlee! ;)

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rpdom
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Re: Difference between B and B+

Wed Jul 30, 2014 8:17 pm

Handy. I do use analogue sound for a couple of Pi's, but the rest run headless and don't have audio out. I have things that could benefit from a second HW PWM on those.

I presume I just need to unload the relevant sound module before I use it?

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Re: Difference between B and B+

Wed Jul 30, 2014 8:19 pm

I presume the PWM driver would do that for you!

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Jim JKla
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Re: Difference between B and B+

Wed Jul 30, 2014 8:43 pm

I caught somthing in passing and I can't remember where but there was something about the B+ having a couple of contacts that would alow you to reset the B+ without having to pull the plug after a shut down.

Is this a new feature of the B+ or just something I missed on the B or is it a couple of the new pins on the extended GPIO.

Given all of the above and under the assumption that it's a couple of contact points and I am not wildly mistaken would it not be better for this to be pins so that you could if wanted mount a switch on a couple of fly leads.

I am prepared to shot at for mis-reading this, I am aware that I have my head well above the parapet and will do my best take the pain of any flack with due humility. ;)
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Re: Difference between B and B+

Wed Jul 30, 2014 9:27 pm

Jim JKla wrote: Is this a new feature of the B+ or just something I missed on the B or is it a couple of the new pins on the extended GPIO.
Shorting the P6 header on the B rev2 can be used to activate the reset pin.
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rpdom
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Re: Difference between B and B+

Thu Jul 31, 2014 5:52 am

Jim JKla wrote:I caught somthing in passing and I can't remember where but there was something about the B+ having a couple of contacts that would alow you to reset the B+ without having to pull the plug after a shut down.

Given all of the above and under the assumption that it's a couple of contact points and I am not wildly mistaken would it not be better for this to be pins so that you could if wanted mount a switch on a couple of fly leads.
Like the P6 header on the B2.x it is an unpopulated 2 pin header. You could solder pins (or wires) into the two holes if you wanted, although I'd be wary of leaving a set of reset pins sticking out if you don't have your Pi in a case.

On the B2.x (and A), the P6 header is between the 3.3V regulator and the HDMI socket. On the B+1.2 the "Run" header is by the edge of the board next to the Display (DSI) socket.

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Jim JKla
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Re: Difference between B and B+

Thu Jul 31, 2014 6:52 am

If the pins are standard pitch it's very easy to protect these with a blank insulated jumper.

Whilst I do understand the reluctance to have the pins bare on an unboxed RPi the thought that I need to solder something to a new pristine board to access an engineered function abhores me as much as having to by pass built in poly fuses.

It smacks of incomplete engineering if the funcion is there then make it easily accessable the board allready has bare GPIO pins not to mention the lack of any sort of cover when supplied tends to negate a lack of potential insulation on two particular pins.

I know this is not an argument for this thread as strictly speaking it's off topic this is more a debate suited to additions I would like to see made to the RPi.

I suppose it is a suggestion that the Foundation lacked some joined up thinking or lazyness in following through as the alternative is braking and remaking the power train at some other point.

I would like to think that the original idea was to place a small surface mount reset button at this point and some bean counting accountant suggested removing the switch could save coppers allowing the RPi to hit a price point.

I would allways prefer to blame an Accountant over an Engineer. ;)
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rpdom
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Re: Difference between B and B+

Thu Jul 31, 2014 7:19 am

But you know very well that the Pi is designed to a very specific price point. The holes are standard 2.54mm pitch, so a normal 2-pin jumper will fit in there. It's a bit tight for a push button.

I'd say just be glad that the option is there rather than having been discarded to save copper ;)

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Re: Difference between B and B+

Thu Jul 31, 2014 2:52 pm

For more info about the reset / run header, see http://raspi.tv/2012/making-a-reset-swi ... spberry-pi
(AFAIK despite the change in name, the P6 and RUN headers are identical)

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Re: Difference between B and B+

Sun Jan 04, 2015 7:01 pm

Seems my post has gone missing.... My questions was - Does the B+ alleviate the crashing that was from the Ethernet and USB sharing the same bus/power? I had past experience of my B model crashing when J had medium traffic in network and medium read/writes on USB.

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