Raspberry Pi Compute Module 3 ReviewA new day is upon us, and it is glorious. After all, it’s not often that a new Raspberry Pi board is released.
Our Raspberry Pi Compute Module 3 Review
Hello what an exciting day this is, my names Sam from Core Electronics and today I’m really really excited to take a first look at the new Raspberry Pi Compute Module 3. It’s been rumoured for a while but we’ve finally got our hands on one and we’re going to take a look at the good and the bad, take a look at whether it’s going to be right for your project and what we think of it. So I’ve got the Compute Module 3 Development Kit here, now the Raspberry Pi Foundation have released 3 different products as part of this new Compute Module 3. So before we go to much into that what exactly is the Compute Module? I’m sure everyone knows the Raspberry Pi 3, it’s fantastic, probably the worlds most popular micro computing platform and its awesome but what about its lessor known brothers, the Compute Module. Well, the Compute Module, the first one was released in 2014 and it was designed to introduce Raspberry Pi, the Micro Computing platform based on Linux to industrial and commercial users and applications. So for those kind of designers they don’t need all of the physical USB ports and HDMI ports, they’d rather just have access to the BCM2837 the Broadcom System-On-Chip (SoC) that has CPU and GPU and all the rest in there. The supporting circuitry and be able to access all the hardware peripherals themselves and control what they want to use in a much smaller form factor and thats exactly what Raspberry Pi gave. Its awesome in the form of a SODIMM card which you might know, you might be familiar with if you’ve used computer RAM before, it’s the same form factor. It’s fantastic but it was languishing a little bit, when it was released in 2014 it had the same specs as the older Raspberry Pi boards back then, 512 MBs of RAM, I think 10 times less processing power on average than the current Raspberry Pi 3. So they’ve upgraded it and we now have the Compute Module 3 which is fantastic.
So, a few things ago about this, we’ve got the Computer Module 3 which brings the same BCM2837 System-On-Chip with 1.2GHz of processor,1GB of RAM, all the same tech specs that you are familiar with the Raspberry Pi 3 but, we’ve also, we’ve got 2 modules here, we’ve got that main Module, now we’ve got a second Module called the Compute Module 3 Lite. Now the difference here is that the main Module has 4GB eMMC Flash Storage on board and each ships as blank, you actually have to install an operating system on that flash data. The easiest way is from another Raspberry Pi, but we’ll get to that in another tutorial.
But this Lite offers another alternative to people where the bus that is used for either SD or eMMC storage is broken out on to the edge connector of the SODIMM package and it allows you to use it as storage external to the board or an SD card, you can actually use the same old SD card as you would use in your regular Raspberry Pi, which is pretty cool.
So I’ve got here today the Development Kit because the Module is all well and good but it’s just a Module, there’s no USB, ahh, physical USB port there’s no HDMI port, no power ports, that’s all on individual Pins. So the Development Kit comes with the Raspberry Pi Compute Module 3 iO Board and that allows you to, it comes with the DDR2 SODIMM socket where you can insert the Module and it breaks out the USB connection, the HDMI, CSI, DSI connectors really really well. So I’ve got that here now let’s take a look, let’s open it up and find out what’s in the box. So, I’ll open this guy up, we’ve go the safety guide and quick start guide, we’ll set those aside for now. It comes with a power supply, an official Raspberry Pi Power Supplier with international adaptors which is pretty nifty. Its the same power supply you use, nothing different in there, very cool. Now we have the iO Board! very important, some more stuff, some foam, a microUSB cable. Now we’ve got here the CSI and DSI Connector Adaptor Modules, we’ve got the Compute Module 3 Lite and more jumper cables. So that’s what in the box.
Let’s take a look first up at the iO Board, now note, you want to handle this carefully as like other Raspberry Pi products they can be particularly sensitive to static damage so make sure you’re not handling the circuit board too heavily. So it’s already got the Compute Module 3 inserted onto here, so the Development Kit comes with both the Compute Module 3 and the Compute Module 3 Lite so it really is a great Development Kit covering all options. I know this because it has, take a look at that circuit board there, you’ll see that there’s a section there where you’ve got a chip and there’s a missing chip there which is normally where that eMMC Flash goes. Whereas on the other side of this Module there will be the eMMC Flash Chip on there, so that’s how you can tell the difference.
So this is the iO Board, lets take a look, we’ve got a microSD Port, a HDMI and it looks as though we’ve got 2 Display Connectors here so you can use these as DSI Connectors to connect up to liquid crystal displays just the same way you would the Official Raspberry Pi touch display and they’ve included a nice little Breakout Board here. So we’ve got one for the camera and one for the display. Now there’s a little V groove there, you probably can’t see it on that top down camera but there’s a V groove running there from production now the idea is that you break those boards apart. There’s no copper that you are going to damage, they’re designed to be snapped apart because they’re not actually going to fit there so one of those is for the camera and the other is for the display - you can’t interchange them, that’s very important. So we’ll set that aside.
We’ve got 2 camera and 2 display port sockets there because the hardware peripherals for the BCM2837 actually include support for both. I’ll got down to where the peripherals are (06:23) yeah so you can see there’s a 4-lane CSI Interface, there’s a 2-lane CSI Camera Interface and there’s a 4 and 2-lane DSI Display Interfaces, very very cool. Camera Serial Interface and Display Serial Interface in case you were wondering. So there we’ve got SD Card, CSI DSI Connectors, we’ve got USB Slave here, so this Port, I believe will allow you to flash the on board eMMC Storage on the Compute Module 3 so you wouldn’t want to do that with an external Raspberry Pi and there’s a process for that, as I said that’s a conversation for another day as this is just an unboxing and a review. Now we’ve got a USB port, that’s the slave USB and we have a host USB port so this is to connect it straight up to the USB bus. Now an important note here is the Compute Modules don’t include WiFi, Ethernet or Bluetooth. This is because WiFi and Ethernet and Bluetooth they all came off a different add on peripheral. So for example with the Ethernet and the 4 USB ports they were chained on to the, it’s got 1 USB-2 Bus, now off a single bus you can have multiple physical hardware ports but on this they’ve only expanded it to a single one. You can add more if you like but you’re going to need a powered USB hub in order to use multiple USB devices. So no WiFi, no Bluetooth, no Ethernet but of course as a hardware designer you could take the hardware peripherals there, the USB bus and add those on in your physical product, that’s up to you. So, I’ve got the USB port there now we’ve got the Power In, taking the familiar microUSB power adaptor and then we have Header Breakouts. So this DDR2 SODIMM Module is actually a 200 Pin package, 200 Pins the size of that. This has approximately a third of the physical real estate that a Raspberry Pi 3 Model B does. You can lay two of those plus an extra one and it’s less than 4mm thick which is so cool.
08:31 So why would you use a Compute Module? That’s a bit about the board and the Development Kit and how you can use it. Well it’s designed for industrial and commercial applications primarily, it’s designed for people who don’t want that physical bulky factor, they want to be able to sleekly integrate it into their products and have access to all the peripherals and all the power of the BCM2837 board but to be able to harness that versatility and flexibility of all those ports and just pick and choose what they want which is really cool. So it’s not really designed for the average DIY Maker to pick one of these up and use it as per they would a traditional Raspberry Pi 3 Board, its actually a different product aimed at a different market.
So with that in mind, bear in mind the different market let’s take a look at the good and the bad of this board because it’s very very cool. So the first point is that it’s a very stable platform, the best thing about the Raspberry Pi Compute Module 3 platform is that it’s made by Raspberry Pi and that means it’s got a well developed operating system, it’s got a huge online community, millions of people around the world are using it and it’s a tested and proven recipe. It’s the same chip that’s on the Raspberry Pi 3 so there’s fantastic software support out there, you’re not being thrown in the deep end, you’re already in that life-cycle which is very cool. We mentioned before the micro form factor - super super small, can fit anywhere and really good for integrating into products with a constrained size.
Now the supporting circuitry and peripherals, we mentioned a bit about that but the cool thing about the Compute Module, I’ve said that about three times now! but the cool thing - there’s so many cool things - but another cool thing about the Compute Module is that it has all that supporting circuitry on there. Once you inserting into the correct adaptor and power is supplied to the correct pins and so on and so forth, it has everything on there that you need in order for the chip to work correctly. This iO Board is just expanding all those pins in to a useable way.
10:27 You can see a bit more about the pins there, 48 GPIO pins so more than is on a standard Pi Board due to size restrictions, HDMI, SD, UART etc etc.
Now we’ve covered a bit about the difference between the CM3 and the CM3L, now one’s not necessarily better than the other, they have exactly the same specs but it just depends on how you want to use the storage, bear in mind that when they announce the price of the CM3L it debuted slightly cheaper than the CM3 which is pretty cool. The CM3 can be picked up for AU$55 and the CM3L can be picked up for AU$46 so a bit of a price savings there, but it doesn’t indicate that one’s a lesser board, they are just there for different applications.
The Compute Module iO Board, of course is a big pro, it’s a fantastically designed board, really solid, really robust and the last thing is the price. The price for the Compute Module 3 environment is fantastic, as I said, the prices of those Modules are really really cheap so if you’re looking to embed those or even just get started as a one off it’s all there.
Now, the bad, there isn’t really a huge amount that I can say that is bad about this platform, it’s fantastic. There’s not a lot of criticism that can be had against the Raspberry Pi platform, especially for what it is. One thing though is the price of the iO Board or the Development Kit as a whole, I should say, it sets you back a little bit but the cool thing to bear in mind is that it has (another cool thing!) it has the iO Board, it comes with the CM3 and the CM3L - both are Modules for prototyping and there’s a lot of engineering inside this, you get the CSI the DSI adaptors, some job wires a microUSB cable, the power supply, it’s all bundled up there as the perfect development getting started kit.
The last thing I guess, is the complexity of using this versus the traditional Raspberry Pi for example, simply to get up and running with the CM3 Module you have to insert it into your iO Board, it’s useless without the iO Board for development. You can’t just plug it in, stick it in the RAM slot in your computer, I guarantee you will break it. You need that iO Board to get started unless you already have the hardware implementation for it. Note that they are not backwards compatible with the old Compute Modules, they share the same sort of form factor, CM3 and CM3L are compatible but they are not electrically pin mapped the same so you can’t interchange there. With that complexity if you want to set up the CM3 Module then first of all it’s blank, there’s nothing on that eMMC storage, the Raspberry Pi can’t boot anything so you have to go through and flash that using another Raspberry Pi and that’s where that slave USB port comes in handy. So there’s a bit to that but more on that in other tutorials. But that’s really the only two weak points I can consider is that extra complexity which if you’re an industrial designer it’s more of a pro if anything because it has that versatility and flexibility that you are after. Thats a quick over view of the Raspberry Pi Compute 3 Module, it’s a fantastic bit of gear, I really like them and I’m excited to try a couple of projects where that might be a much better application rather than a whole big traditional Raspberry Pi 3 Board. Same power, more hardware peripherals because you get more access to the BCM2837 but a bit more care to be taken with the design.
So that’s a bit about that, my verdict - our verdict - it’s awesome if this is what you’re after, this kind of development environment platform then it’s perfect. Grab yourself one of these today and start making and if you’re after any more tutorials or information check out our tutorials module and we’ll have more things up and going there as we continue to dive in with this board and find out more about some of the cool features there. Check out the projects module, hopefully we’ll have some projects up to inspire your next big project, product, application - what ever it is. I’m Sam from Core Electronics, happy making guys :-)