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Tim Blythman takes a close look at the latest “Pi”: Raspberry Pi 3 Model B+ Arguably one of the most popular – and therefore most successful – singleboard-computers in the world today, the “Pi” can be found everywhere from the experimenter’s bench to revolutionary commercial products. The latest version, the 3B+, has a few niceties to make it even more capable! T he Raspberry PI 3B+ was released on Pi Day (March 14 or 3.14, maybe it makes more sense if you write your dates backwards!). It was six years ago that the first Raspberry Pi single-board computer (SBC) was released and in that time, 1.4GHz PROCESSOR SPEED there has been a variant or two released each year, with sales around 5 million units worldwide per year. If you Google “Raspberry Pi”, you’ll get somewhere around 181 million hits, ably demonstrating the popularity of this device! 40 GPIO PINS (26 I/O pins compatible with previous models) Moreover, if you’re looking for a particular Raspberry Pi application, the chances are very good that someone, somewhere has done just that – or something close enough that can be adapted to suit. And because of backwards compatibility, you should have POWER OVER ETHERNET (PoE) 5GHz WiFi FOUR USB PORTS MICRO SD STORAGE 10/100/1000 BASE-T ETHERNET DSI DISPLAY Features arrowed in Pi Green are new on the Model 3 B+; features arrowed in Pi Red are on some older models as well. siliconchip.com.au 5V POWER IN (MICRO USB SOCKET) HDMI SOCKET Australia’s electronics magazine 4-POLE 3.5mm SOCKET (STEREO AUDIO & COMPOSITE VIDEO) July 2018  57 Raspberry Pi Release Architecture Processor Memory Network GPIO pins WiFi Model 1B April 2012 ARMv6 32-bit 700MHz 512MB 10/100 Mbit 17 None no difficulties there. A surprise? The release of a model 3B+ came as a bit of a surprise, given that the rumoured Raspberry Pi Model 4 was expected to be released some time in 2019. With the Raspberry Pi Foundation noting a shift in their efforts towards software, this will no doubt push the ‘next Pi’ even further into the future. The Raspberry Pi Foundation is keeping their cards close to their chest on this one but that is to be expected, when it appears to be consistently setting the same low price point for new versions of their hardware. On the Foundation’s product page, there is also an obsolescence statement to the effect that the model 3B+ will be in production until at least January 2023. Interestingly, there does not seem to be a similar statement on any of the other models (except the cut-down Pi Zero), so we may see the Pi 3B+ around for a while. Educational background In the spirit of the Acorn BBC Micro, the Raspberry Pi started out as a computer suitable for education (much of the software included on the default Raspbian operating system still Model 3B February 2016 ARMv8 64-bit 1200Mhz 1GB 10/100 Mbit 26 802.11n 2.4GHz Model 3B+ March 2018 ARMv8 64-bit 1400MHz 1GB 10/100/1000MBit 26 802.11ac 2.4GHz/5GHz has an educational intent). But it has become the inexpensive computer of choice for all manner of DIY projects, such as arcade game emulators and media players. A (small?) step up While the step from model 3B to 3B+ sounds more like evolution than revolution, there are certainly some interesting changes which may make the newer model much more suitable for some new projects. Some core specs have not changed since the model 3B was released two years earlier. The new Pi still has 1GB of RAM, four USB ports, an HDMI socket and a 3.5mm TRRS socket for audio and composite video. The 40pin GPIO header remains the same, as does the remainder of the other main board features and physical compatibility appears unchanged. Network hardware Two of the biggest changes are in network hardware. The Pi 3B+ now has Gigabit Ethernet (although it is limited to 300Mbps practical throughput due to USB limitations) and 5GHz WiFi. This is a great advantage for users who are using the Raspberry Pi for Internet of Things Projects, especially as there is now modular compliance The front-side photo opposite is shown significantly over-size, for clarity. This shot, of the back of the unit, is reproduced same size (PCB is 85 x 55mm) so you can get a much better idea of the amount of power packed into the Pi. 58 Silicon Chip certification for the WiFi, meaning it is easier to certify products created around the Pi 3B+. The small metal can embossed with a Raspberry Pi symbol (top left) is the obvious visible change of the WiFi upgrade and the improved WiFi layout also appears to have improved the 2.4GHz range as well as adding 5GHz. There’s also a header designated for PoE (power over Ethernet) next to the GPIO header, although a separate HAT (Hardware Attached on Top) board is required to make use of the PoE function. Coupled with the introduction of PXE network booting (and USB booting) on the Model 3B, this means the Pi 3B+ can more easily be set up to boot and operate remotely in out of reach areas remotely. Benchmarks The processor speed is now 1.4GHz, up from the 1.2GHz of its predecessor, with the main system-on-a-chip also sporting a metal ‘heat spreader’ (as described by the Raspberry Pi Foundation). The obvious benchmarking tests and comparisons that have been run show no surprises in performance compared with the 3B, although the percentage rise in power consumption appears to be over double the performance gains. The 3B+ specifies a 2.5A power supply compared to 2A for the 3B. Power management An interesting addition which no doubt helps the new Pi achieve higher speeds is the dedicated power management IC. The MXL7704 was actually developed specifically for the Raspberry Pi 3B+, and controls a total of six supply rails, including one of the nominal 1.2V supplies, which is adjusted depending on processor load. There is the incoming 5V rail, two 3.3V rails, a 1.8V rail and two 1.2V rails, and the IC is controlled via I2C. That the Raspberry Pi Foundation can have an IC specifically developed for one of their products gives an indication of how popular the new board is expected to be. Other SBCs A comparison with some of the other single-board computers available is shown in the table overleaf. The influence of the Raspberry Pi range is seen in how much some of the other Australia’s electronics magazine siliconchip.com.au The 40-pin GPIO header socket on the Raspberry Pi 3B+ is compatible with earlier 26-pin headers – the first 26 pins are identical, which makes any hardware you’ve created for earlier Pi versions work just the same as on the 3B+. boards are attempting compatibility with things such as the Raspberry Pi dimensions and the GPIO header. The Orange Pi PC Plus and Odroid C1+ almost appear to be drop-in substitutes dimension wise, and along with the PCDuino Nano 4, sport the same 40 pin header. There is little doubt that these three boards are all hoping for some share of the Raspberry Pi market. Give or take missing features like WiFi or IR receiver, these three boards would no doubt do a similar job hardware wise. The BeagleBone and Pine boards have a slightly different audience, which may or may not be suitable for specific uses. The Beaglebone Black Wireless looks to have lower specifications, but the provision of its many IO pins backed by the PRU (Program- mable Realtime Unit) means it is better suited to operations that require high performance of directly connected peripherals. The Pine A64 LTS (LTS stands for Long Term Supply, and has been promised to be available until 2022) is larger and probably has higher specifications that even the new Raspberry Pi. Nonetheless, it still calls its 40 pin header a ‘PI-2’ type. While some of these boards appear to be cheaper than the Raspberry Pi, what will be missing is user support. For example, I recently tried to upgrade an older model PCDuino 3B to Ubuntu 16.04, and there was no support for this, meaning newer packages were impossible to install. It appears that linux-sunxi.org is working to maintain support for some AllWinner based boards. Software On the other hand, the latest build of Raspbian (the official Raspberry Pi Foundation operating system) is still claimed to be compatible with the Raspberry Pi Model 1. For new users, the ease with which a Raspberry Pi can be set up is what clearly sets it apart from other single board computers. The large community which has grown up around the Raspberry Pi also assists all users in many ways. There is no doubt that the new Raspberry Pi 3B+ will continue to be popular for these reasons. Summary Features that we would see being the Where from? Altronics: www.altronics.com.au/p/z6302c Element14: au.element14.com/2842228 More reading: https://hackaday.com/2018/03/14/ raspberry-pi-gets-faster-cpu-andbetter-networking-in-the-new-model-3-b/ https://en.wikipedia.org/wiki/ Raspberry_Pi www.raspberrypi.org/products/ raspberry-pi-3-model-b-plus/ www.raspberrypi.org/blog/pi-power-supply-chip/ https://medium.com/<at>ghalfacree/benchmarking-the-raspberry-pi-3-b-plus44122cf3d806 big selling points are the combination of PoE and network boot, allowing a Pi 3B+ to be connected, set up, powered and running off nothing more than an Ethernet cable. The modular certification combined with 5GHz WiFi make the new model of the Pi a great candidate for incorporation and integration into consumer products. So is it worth upgrading? The new model is slightly more expensive than the 3B, so we’d expect that the shift to the Pi 3B+ to be steady rather than instantaneous, with some, but not all, users quick to jump on the new features. SC COMPARISON OF RASPBERRY PI 3 B+ WITH OTHER COMMON SBCs Raspberry Pi Orange PI PC Plus BeagleBone PCDuino 4 Nano Model 3B+ Black Wireless RRP (USD) $35.00 $24.00 $70.00 $30.00 Architecture ARMv8 64bit AllWinner H3 Cortex A8 AllWinner H3 Processor 1400MHz 1600Mhz 1000MHz 1200MHz Memory 1GB 1GB 512MB 1GB Network 10/100/1000Mbit 10/100 Mbit None 10/100Mbit Breakout Headers 40 pin 40 pin 2 x 46 pin 40 pin WiFi 802.11ac 802.11n 802.11n None 2.4GHz/5GHz Host USB Ports 4 3 1 3 Storage Micro SD slot 8GB eMMC onboard, 4GB eMMC onboard Micro SD slot Micro SD slot Other IR Receiver 2 x PRU Peripheral IR Receiver, microcontrollers Microphone Main Supported OS Raspbian, Ubuntu, Android, Ubuntu, Debian, Android, Debian, Ubuntu Windows 10 IOT, Raspbian Ubuntu Size 85 x 56mm 85mm x 55mm 87 x 54mm 64mm x 50mm siliconchip.com.au Australia’s electronics magazine Pine A64 LTS Odroid C1+ $32.00 AllWinner R18 1152MHz 2GB 10/100Mbit 40 + 34 pin 802.11n $35.00 Cortex A5 1500MHz 1GB 10/100/1000Mbit 40 pin None 2 Optional eMMC and Micro SD slot Battery port 4 eMMC Socket, Micro SD slot IR Receiver, RTC Linux, Android Ubuntu, Android 130mm x 80mm 85 x 56mm July 2018  59