machinabio wrote:Since the new Pi 2 was announced, I'm curious what the plan is on revising the compute module? The new ARMv7 architecture would make a world of difference to my application. We had to do a lot of extra work to get a NodeJS/Meteor app running on a Pi. It works fine for a demo, but for a production application we were considering switching to a beagle bone specifically because of the ARMv7 architecture. If we had that on a compute module, we could get everything running smoothly pretty easily.
Looks like compute v2 will be compatible.Q. When the version 2 Compute Module becomes available will we able to do a straight swap from the version 1 module?
A. That's what I've been told
why?mikemoy wrote:Tiny bit disappointed that it will be backward compatible, though I understand why.
I would have really liked to see you guys throw on the LAN9514 onto the CM.
On the BCM2835 the core voltage is provided by an on-chip adjustable switching regulator supplied through the "VBAT" pin of the SoC. On the Pi1 "VBAT" is connected to the 5V line. On CM1 "VBAT" is brought out to the edge connector and the hardware design guide says you can supply it with anywhere from 2.3V to 5V. On the compute module IO board VBAT is connected to 3.3V (dunno why they went for 3.3V and not 5V)wirelesstings wrote:Does that mean the regulator is different on the PI2 than the Compute base board. We might have time before the OpenPi kickstarter ends to revise if necessary.
Given that the SoC connections should be identical to those on the Pi 2 B (which for all intents and purposes _is_ a Pi 2 B+ from what I can tell - 4 USBs, B+ voltage regulators, "non-mounting alignment" holes, etc.), the PCB layout for that portion of the CM2 is already done. Since the flash RAM for the CM2 will likely be the same 4 GB on the CM1 that part of the layout is also done (lots of OS features and app packages fit well within 4 GBs of space). Most of what needs to be done is routing Pi 2 unique connections (if any) to the SODIMM board edge connectors, and the second 90% of what needs to be done is the FCC/CE compliance testing and mods (the first 90% of a project takes 90% of the allotted time, and the last 10% takes another 90% of the allotted time ).RaTTuS wrote:as the RAM is not POP now it will be more a a redesign on the package than a simple replacement chip
I've been disappointed, but not surprised, by the slow uptake on the CM, at least in production volumes. I wonder how many dev kits were sold, as that would give a clue as to how much interest there really was. My take was that netbook and tablet component manufacturers were some of the larger anticipated customers and given that we see new Android tablet designs every week (each of which can't possibly be making any money on their own, what with their paltry individual model sales numbers) it is a bit puzzling why we haven't at least seen a basic netbook based on the CM(1) (and the performance and screen size would put such a device firmly in the netbook, and not laptop, category). The Slice doesn't really count since its form-factor is anything but modest in size, composition ... or especially price - I have no idea why they used the CM(1), particularly in light of Gordon's statement where drop-in compatibility between a potential CM2 and the CM(1) isn't guaranteed, AIUI.10robinho wrote:I hope we will see CM2 soon, I'm sure there are many industrial customers (like us) that already have big plans with this little thing
The compute module has every IO pin hooked up, the B series doesn't. So the layout under the processor will need work to get those connections out. I don't know how difficult said work will be (it depends a lot on how the ball arrangemnets of the 2836 match up with where the signals need to go).Jim Manley wrote:Given that the SoC connections should be identical to those on the Pi 2 B (which for all intents and purposes _is_ a Pi 2 B+ from what I can tell - 4 USBs, B+ voltage regulators, "non-mounting alignment" holes, etc.), the PCB layout for that portion of the CM2 is already done. Since the flash RAM for the CM2 will likely be the same 4 GB on the CM1 that part of the layout is also done (lots of OS features and app packages fit well within 4 GBs of space). Most of what needs to be done is routing Pi 2 unique connections (if any) to the SODIMM board edge connectorsRaTTuS wrote:as the RAM is not POP now it will be more a a redesign on the package than a simple replacement chip
I agree with that. As I said couple of posts earlier, I can't wait to get CM2 released.jamesh wrote:Why do people think the CM hasn't been selling? Figures have never been released.
Consumer items (like Slice) are only one part of the CM's abilities, there are lots of industrial applications that could use them that the huge majority of people would never hear about.
I was about to ask if operations were on the UK Continental Shelf but there you get a paltry 12 atmospheres at depth... You have to be on the Abyssal Plain depths to get 400 bar...TangoMikeBravo wrote:We're interested in using the compute module to replace PC104 Intel processors for subsea applications where the processor has to run at seabed pressures of up to 400 bar. The main problem with any of the Intel-based PC104 units is that there are usually two or three crystals on the board (processor, Etherent and sometimes another, not sure what it's used for). These are pretty much the only pressure-intolerant components and we have to make special provision to protect them from pressure. On the simpler stuff like Ethernet switches, we do that by ripping the crystal off the board and replacing it with a MEMS oscillator, which we have tested and works nicely at the highest pressures we can test (400bar). We can't do that with the PC104 processors though because they're quite densely packed on the PCB making it quite difficult to rework and there's usually not space to fit the MEMS. That means we have to bodge them with a metal cap and epoxy to isolate them from the pressure environment, which works well enough up to 100bar but is unreliable above that.
The RP2 though, and the first generation compute module, are nicely laid out which makes removing the crystal and replacing it a doddle, and I'm about to start a round of pressure testing on them to see if there are any other gotchas, but I suspect they'll be fine, particularly the CM which we would prefer to use because we can then choose known good components for stuff like Ethernet magnetics and the like on a motherboard we can make ourselves.
We're not quite sure that the original CM is powerful enough for us though, but the RP2 certainly is and we're looking forward to the Rev 2 CM (assuming everything else passes the presssure qualification of course). Not that our volumes will make a difference to the Foundation's bottom line, at a few 10s a year though
Arr, no, it's one bar per 10m of seawater depth. The UK and Norwegian oil and gas lines currently operate up to about 1000m or 100bar and are being expanded to areas over 1300m or 130bar. There are fjords in Norway with depths of over 1000m, for example Sognefjord where we have tested some stuff has a maximum depth of about 1300m. Some wells overseas are drilled at about 3000m below the sea surface, hence the 400 bar requirement (to give a safety overhead).jdb wrote:I was about to ask if operations were on the UK Continental Shelf but there you get a paltry 12 atmospheres at depth... You have to be on the Abyssal Plain depths to get 400 bar...
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