awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Compute Module

Fri Jan 12, 2018 7:38 pm

What can you do with the RPi 3 Compute Module?

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Fri Jan 12, 2018 8:08 pm

Anything you can do with any other Pi (given an appropriate carrier board), plus a whole lot more. The CM line is intended for embedded/industrial use. There is a sub-forum here devoted to the CM, though most of the traffic there is--unsurprisingly--devoted to issues and problems.

Like the Pi0/Pi0W, the CM/CM3/CM3L are not really good Pis to start with. Rather, they are useful when you have some very specific needs or are developing a product that needs a System on a Module, rather than a Single Board Computer. While the CMs are inexpensive in and of themselves, the carrier boards aren't always. The development carrier board (CPIO3) is (or, was, last I looked) about $120.

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Sat Jan 13, 2018 8:52 pm

I noticed that it says that the module has the "guts if the RPi 3". Does this include the integrated graphics? I heard that it doesn't have integrated graphics.

User avatar
fruitoftheloom
Posts: 16459
Joined: Tue Mar 25, 2014 12:40 pm
Location: Bognor Regis UK

Re: Compute Module

Sat Jan 13, 2018 9:04 pm

awesomelydeluxe wrote:
Sat Jan 13, 2018 8:52 pm
I noticed that it says that the module has the "guts if the RPi 3". Does this include the integrated graphics? I heard that it doesn't have integrated graphics.

All RPi and CM use a SoC which includes both a GPU and ARM CPU:

https://en.wikipedia.org/wiki/Raspberry_Pi

https://www.element14.com/community/doc ... e-module-3
""understanding the theoretical, but not always the end goal""

My other Devices are the ChromeBit CS10, ChromeCast & Huawei Mate 10 Pro SmartPhone

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Sun Jan 14, 2018 12:14 am

awesomelydeluxe wrote:
Sat Jan 13, 2018 8:52 pm
I noticed that it says that the module has the "guts if the RPi 3". Does this include the integrated graphics? I heard that it doesn't have integrated graphics.
The VC4, which is well over 90% of the Silicon in the SoC is the Broadcom VC4 GPU. That is part of all Pis, so far, and one would expect that it--or a follow-on upgrade of it--will be in any new SoC used in any future Pi. The SoC *is* the "guts of the RPi 3". The only other major components that is on the CM3L is a 1GB RAM module. The CM3 adds 4GB of eMMC flash. The NEC version of the CM3 replaces the 4GB eMMC with 16GB of eMMC.

I would be curious to know where you "heard" that the CM lacks the integrated graphics. Mostly, I'd like to know who is spreading disinformation and whether is it is done through ignorance or if it is malicious. In either case, thank you for *asking* so that we can set the record straight.

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Mon Jan 15, 2018 6:10 pm

So the CM is actually better than the RPi 3/B?

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Mon Jan 15, 2018 6:39 pm

awesomelydeluxe wrote:
Mon Jan 15, 2018 6:10 pm
So the CM is actually better than the RPi 3/B?
(Note: I am reading the question as referring to the CM3. The CM uses the original Model B/Model A/A+/B+/Pi0/Pi0W(H) SoC...single core ARMv11, 700MHz to 1GHz, 512MB RAM with 4GB eMMC added.)

Define "better". It's the exact same SoC. The exact same RAM. One can argue whether whether on not 4GB of on-board eMMC flash is "better" or not. For one thing, it isn't enough to hold the full Raspbian with a GUI desktop and all the extra software that comes with the package. It does expose additional interfaces (second camera, second display, *all* the GPIO), but you have to have/make a carrier board to access them.

On the other hand, a Pi3B has everything you really need to get started right there. Power circuitry, connectors, GPIO header. Just plug it in and go. Plus, if you trash the OS, you can rewrite the SD card and be back up and running very quickly. Or you can have cards with different OSes on them and running a different OS is just a shut-down-and-swap-cards away. (Granted, you can do that with a CM3L, too, but you still have to add a carrier board and it would have to have a card holder.)

For anyone looking to play around with/experiment, the CM3 is interesting but hardly "better" than a Pi3B. For a commercial product as an embedded SoM, well...that's what the CM series was designed for, yes, it would be the better choice. It all comes down to the use case.

I think what it really comes down to is "better for what?"

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Mon Jan 15, 2018 8:37 pm

OK, so this is what I've seen so far that's different:
1. Internal flash memory
2. Needs an IO board
3. More expensive
4. Open source (yay!)

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Mon Jan 15, 2018 9:55 pm

awesomelydeluxe wrote:
Mon Jan 15, 2018 8:37 pm
OK, so this is what I've seen so far that's different:
1. Internal flash memory
Yes--though not on the CM3L. Also "different" (in this case does not necessarily mean "better".
2. Needs an IO board
Yes, and the I/O board can be customized. The development board (done by the RPT), exposes lots of GPIO connections as well as both camera and display interfaces, but only a single USB connector. On the other hand--to give an example--the WD SATA Adapter has two USB ports, no Ethernet connector, no GPIO pins, no DSI, no CSI, but it does have a SATA connector...and an actual power switch.
3. More expensive
The CM3 sells for less than a Pi3B, and the CM3L sells for less than the CM3. The development carrier board costs considerably more. The WD SATA Adapter is less than a Pi3B, but a CM3 (or CM3L) plus the SATA Adapter comes to more than a Pi3B.
4. Open source (yay!)
The interface (the SODIMM-style edge connector) pinout is published. I don't know how that works with regards to your--or anyone else's--definition of "open source". The binary blob it takes to boot a CM/CM3/CM3L is the same closed source code that boots any other Pi.

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Tue Jan 16, 2018 12:14 am

I'm thinking of making a media center out of this, like Slice http://fiveninjas.com/index.html
Is it hard to make stuff with the module?

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Tue Jan 16, 2018 12:19 am

awesomelydeluxe wrote:
Tue Jan 16, 2018 12:14 am
I'm thinking of making a media center out of this, like Slice http://fiveninjas.com/index.html
Is it hard to make stuff with the module?
How are you at circuit board design and surface mount soldering? Remember that you will be responsible for having the required power and power safety circuitry correct as well as an interfaces you want on the carrier board.

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Tue Jan 16, 2018 2:29 am

I've actually never soldered anything before. So for the CM + an I/O board you need a power PCB?

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Tue Jan 16, 2018 3:31 am

awesomelydeluxe wrote:
Tue Jan 16, 2018 2:29 am
I've actually never soldered anything before. So for the CM + an I/O board you need a power PCB?
The power circuits are generally on the carrier board PCB.

If you really want to move forward with a project of developing your own carrier board, I would suggest two things. First, buy an RPF/RPT development carrier board (CMIO3). You can get just the board, or you can get it in a kit with, among other things a CM3 and/or a CM3L. Examine the board to see what is on it. The second suggestion is that you actively read the Compute Module forum. If you have questions about the CM, that is a good place to ask them. You will also see the areas that people have issues with. Like any forum, most of what you'll see are problems. After all, when everything works the way we like, we don't bother to post.

Again, bear in mind that the CM and the custom carrier boards to go with them are--generally speaking--industrial or embedded projects done by companies. Most of the time, those companies will have teams of people with the relevant knowledge and skills to do the work in-house. Still...if you want to *develop* the needed expertise and skills and--perhaps--become a professional in the field, learning to make your own CM carrier board is certainly one way of going about it.

In the mean time, there is something simple and useful far beyond working with CMs that you ca do. Learn to solder.

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Tue Jan 16, 2018 3:34 am

So basically I can use any kind of board I want as long as it works with the CM3? So when I get experience, I can make my own?

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Tue Jan 16, 2018 4:26 am

I'm not one to make PCB's, but to put them to others instead. Since I don't want to do it by myself, is there a place where I can get a custom made I/O board?

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Tue Jan 16, 2018 5:02 am

awesomelydeluxe wrote:
Tue Jan 16, 2018 3:34 am
So basically I can use any kind of board I want as long as it works with the CM3? So when I get experience, I can make my own?
You *really* need to get your hands on the RPF CMIO3 board so you can get a glimpse of what is involved. I trust that you are aware that it is quite common to have 4 or more layers with winging and ground planes in them.... Designing a modern PCB is a complex process and it's really a 3D structure. What the CM3 does is to take the hardest part of the design--putting that in the module--so that the carrier can be *comparatively*--but not absolutely--imple.

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Tue Jan 16, 2018 5:07 am

awesomelydeluxe wrote:
Tue Jan 16, 2018 4:26 am
I'm not one to make PCB's, but to put them to others instead. Since I don't want to do it by myself, is there a place where I can get a custom made I/O board?
I'm sure Element 14 could do it through their custom Pi program. Of course, you'd have the up front expense of covering the engineering development charge and you have to commit to buying 3000 to 5000 of the boards once they've been made... Alternatively, if you can find a local maker space, there may well be people there who could help you get started and might have the equipment to make a one-off, fairly simple, carrier board...or know of companies that will make small (i.e. 10 or less) runs from your design. There is the minor problem that if your design doesn't fork for some reason (even the pros don't always get it right the first time...or the second), then you'll have to pay for another set with a revised design. Repeat as needed.

User avatar
Paul Webster
Posts: 726
Joined: Sat Jul 30, 2011 4:49 am
Location: London, UK

Re: Compute Module

Tue Jan 16, 2018 6:02 am

awesomelydeluxe wrote:
Tue Jan 16, 2018 12:14 am
I'm thinking of making a media center out of this, like Slice http://fiveninjas.com/index.html
Is it hard to make stuff with the module?
To get an idea of how hard it is, take a look at the public information (e.g. About and Forum pages) on the fiveninjas site.
Their objective was different to yours in that they wanted to build a commercial product but look how long it took and look at the skills and connections that they brought.
Slice is no longer sold as a commercial product.
You might be able to buy an old Slice - sometimes people offer them for sale on that forum.

However, you can make a great media centre using a regular Raspberry Pi and you do not need any software/hardware engineering skills at all.

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Tue Jan 16, 2018 4:56 pm

Actually... WD makes a media stick based on the CM... https://www.wdc.com/products/wdlabs/med ... WDLB004RNN

awesomelydeluxe
Posts: 86
Joined: Tue Dec 26, 2017 3:24 am

Re: Compute Module

Wed Jan 17, 2018 1:41 am

It's just the whole industrial application and custom I/O board that I was interested in.

W. H. Heydt
Posts: 8294
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Compute Module

Wed Jan 17, 2018 1:50 am

awesomelydeluxe wrote:
Wed Jan 17, 2018 1:41 am
It's just the whole industrial application and custom I/O board that I was interested in.
As a concept or to go into a business? Once more, I can't emphasize enough that if you are interested in the CM, read the Compute Module forum. That's where the active CM discussions take place.

Return to “Compute Module”

Who is online

Users browsing this forum: No registered users and 2 guests