USB discussions getting a bit heated

Reading that "USB - the Elephant in our Room" thread on the RPF forum again is really depressing.

From the fanbois' typical "It works for me so your complaints make no sense", or "You shouldn't expect it to work because the Foundation makes no money", to JamesH's repeated strawman of "We would need to test EVERY SINGLE USB DEVICE", it makes you wonder what it is about the Foundation that its most vocal defence comes from those with impaired logic ability.  The correlation seems strong.

There's probably some kind of thesis in psychiatry available there.

Reading that "USB - the Elephant in our Room" thread on the RPF forum again is really depressing.

Don't read it then   I think it's unfortunate that while there's a couple of people who seem willing to discuss solutions, Pete & dom spring to mind, most of the productive discussions are getting swamped in the noise.

obviously don't expect to power the thing from the regular 3V3 power supply.

What, no 1.8v version that I can power from the lan9512 ? 

Nice looking board..  I know it'll work - Chris Boot and Simon Arlott were using them along with sd-card on spi during their 3.5 kernel efforts.

Hmmm another alternative would be, based on something close to the current design but fixing the power supply issues and other things that Pete may have on the list, os for the distributors to bundle the board with a power supply, keyboard and mouse that were proven towork at an attractive price, and it can still be a low cost platform for education.

But a that time, I'd guess that some Linux distro would be running on the APC board, yes sans GPIO now and a bigger board but you get other features ...

-J

selsinork wrote:

 

Ok, but... Alternatives ?

Zillions of alternatives, as long as one is free to choose designs and components in response to functional requirements.  Unfortunately RPF is driven more by politics and facial egg than by engineering so it's academic, but anyway ....

The simplest solution is to use the most appropriate SoC or SoCs for Pi version 2.  If the BCM2835 is still the best multimedia device available, fine, use it, but it's crap for USB, networking, and computing, so put another SoC next to it to do those functions better.

This is no theory, I'm looking at the basis of a solution here on my table.  Since the BeagleBone's TI AM3358/9 SoC costs $5 in volume, throw away the Pi's LAN9512 and add the TI SoC instead.  That would give the Pi a more powerful Cortex-A8, on-chip Ethernet MAC, two on-chip USB (one host and one OTG I think), and a zillion hardware ways of interfacing to the BCM2835 for multimedia.

It's totally pointless even thinking about it though.  RPF has all the mobility of a block of granite entombed in an ancient lava flow.

Morgaine.

If the BCM2835 is still the best multimedia device available, fine, use it,

I'm still uncertain how that matters. Right now all that potential still hasn't found an outlet. Lack of codecs prevents serious multimedia use and lack of accelerated X driver means you get no benefit elsewhere. Those things are being worked on, but without a timetable. So it could still be the best unused multimedia device in 5 years.

Since the BeagleBone's TI AM3358/9 SoC costs $5 in volume, throw away the LAN9512 and add the TI SoC instead.

Hmm. I'd be tempted to throw away much more.  I know it's been commented on before, but if that thing is $5 why hasn't someone done something like the Pi at equivalent cost using it ?  Or alternatively is the BCM2835 available to RPF at significantly less ?

selsinork wrote:

 

If the BCM2835 is still the best multimedia device available, fine, use it,

I'm still uncertain how that matters. Right now all that potential still hasn't found an outlet. Lack of codecs prevents serious multimedia use and lack of accelerated X driver means you get no benefit elsewhere. Those things are being worked on, but without a timetable. So it could still be the best unused multimedia device in 5 years.

+1.

Reminds me of another unrelated discussion I was having, about hidden costs and liabilities.

The BCM2835's closed nature is proving a liability to the Pi community already, and the USB core's closed nature is proving a liability to Broadcom already, as well as to the community.  It's somewhat incredible that the Pi is being marketted on the multimedia strengths of the BCM, yet neither X11 nor open media players like mplayer are accelerated yet just because it's closed tight as a drum.

Well I suppose I'm "reaching out" to Broadcom/RPF and throwing them a crumb (not that they deserve it) by suggesting to continue using their device to handle the graphics at least, but in reality you're right.  Designing in a liability is not sensible.

Morgaine.

[Addendum:  It's worth pointing out that chucking out the BCM2835 wouldn't leave us without graphics.  The TI AM3358/9 contains a PowerVR SGX530 GPU, and it's no slouch.  Of course it's nearly as closed as the Broadcom so it's still a liability, but it comes for free with a Cortex-A8 and proper USB and Ethernet controllers.  Oh and <shock horror>, documentation.]

PS. I've  just discovered that the Ethernet MAC on the TI AM 3358/9 is 10/100/1000 !!  It's only the PHY on the BeagleBone that limits it to 100Mbps.  So it's even more "proper" than I thought. :-)

Morgaine Dinova wrote:

PS. I've  just discovered that the Ethernet MAC on the TI AM 3358/9 is 10/100/1000 !!  It's only the PHY on the BeagleBone that limits it to 100Mbps.  So it's even more "proper" than I thought. :-)

Actually, the AM3358/9 have versions with two 10/100/1G Ethernet ports which can be coupled to make a three port Ethernet switch (the third port being the CPU).  It also has support for IEEE 1588 Precision Time Protocol, if you really want to know what time it is

John Beetem wrote:

 

Actually, the AM3358/9 have versions with two 10/100/1G Ethernet ports which can be coupled to make a three port Ethernet switch (the third port being the CPU).  It also has support for IEEE 1588 Precision Time Protocol, if you really want to know what time it is

Awesome chip.  It needs someone to make a rock-bottom board using it to compete at the Pi price niche.

There are quite a few things that could be whittled off the BeagleBone to bring the BOM cost down from $89:

• The PMIC expansion header and LCD/backlight interface are not essential.
• The PMIC itself has a lot of extra features outside of power management that may be superfluous in a bottom-end board so a cheaper PMIC may be available.
• The front-end USB hub is not essential.
• The front-end FT2232H that connects to the USB hub is not essential.
• The BeagleBone's USB device/host flexibility could be reduced by routing the SoC's two USB OTG ports to a combined host USB connector for lower cost.
• The reset button is not essential.
• The two large expansion headers provide good physical support for daughterboards, but could be shortened to reduce cost.
• If one must play RPF-type marketing tricks, don't supply the micro-SD card with the board.
• It must be remembered that in addition to BOM reductions, there will be at least one increase:  HDMI socket and associated circuitry, which must be on-board..

I bet that such reductions could get the BOM cost down down to the Pi price niche for Pi-type volumes.  BeagleBone is made in much smaller volumes than Pi, so their volume price breaks are probably not very good currently, but with volume sales that would change dramatically.

Morgaine.

Morgaine Dinova wrote:

 

I bet that such reductions could get the BOM cost down down to the Pi price niche for Pi-type volumes.  BeagleBone is made in much smaller volumes than Pi, so their volume price breaks are probably not very good currently, but with volume sales that would change dramatically.

I think the key here is volume.  In large volumns BB could probably come down to under US$50 even with the current BOM, and the DVI cape could come down to US$15 instead of US$50.  Another cost factor is USA manufacturing, but I'm happy to pay a bit more and not wonder about quality.

I like having a separate video cape so you have the choice of VGA (coming soon!) or LCD.  But à la carte is always going to be more expensive.

True, the flexibility of BeagleBone is very high, but unfortunately price is king.

Sadly, the board is priced above the point on the budget radar where price is no barrier for the average pocket in the "West" (often said to be the price of an evening out).  But the board is also so well specified that there is ample room for a bottom-end product of that line created through feature reduction.

The Beagle family would be rounded off beautifully with a "BeagleBite" (to stay within their naming meme), where everything except reliability is sacrificed at the altar of BOM cost.  And when sales rocket in reverse exponential proportion to price, the team would find itself with a whole product line ready to cater for different use cases, unlike Pi.

Morgaine.

Actually, the AM3358/9 have versions with two 10/100/1G Ethernet ports

Doesn't take a lot of imagination to realise that a lot of people would be interested in a cheap device with two decent ethernet ports.  Different target market, but still.  With three configurations, one with usb only for all the weird wifi lovers, then single wired port and dual wired port versions you have an interesting device.

Only question is whether the Arm is fast enough to deal with two 1G ports. I've come across a fair few of those little nas enclosures that do have 1G ports but barely manage 100M speeds on them.

Actually, the AM3358/9 have versions with two 10/100/1G Ethernet ports

Doesn't take a lot of imagination to realise that a lot of people would be interested in a cheap device with two decent ethernet ports.  Different target market, but still.  With three configurations, one with usb only for all the weird wifi lovers, then single wired port and dual wired port versions you have an interesting device.

Only question is whether the Arm is fast enough to deal with two 1G ports. I've come across a fair few of those little nas enclosures that do have 1G ports but barely manage 100M speeds on them.