HackSpace magazine

Raspberry Pi 3B+

By Ben Everard. Posted

There’s a new Pi in town: the Raspberry Pi 3 Model B+. It’s an upgrade to the previous version 3 Model B. For followers of this little board, its form factor will come as no surprise – it’s the layout that’s remained more or less unchanged for almost four years. However, within this form, there’s some important developments.

The most obvious changes on the new board are the shiny bits of metal hiding a couple of chips. The largest of these covers the System on a Chip (SoC). While this contains the same quad-core processor as on the Pi 3B, there’s a change in the design of the substrate, and more efficient heat dispersal through the heat spreader. These improvements mean it’s now clocked at 1.4 GHz (up from 1.2 GHz on the Pi 3B).

The second big change is also hidden behind metal. The Pi logo conceals a CY43455 chip, which controls the wireless networking. This chip works with both 2.4 GHz and 5 GHz networking (802.11 b/g/n/ac), meaning that the Pi 3B+ can connect to a wider range of WiFi networks than earlier generations, as this allows you to avoid the more congested 2.4 GHz range, giving you the potential for a network speed-up.

The third big change is the introduction of Gigabit Ethernet thanks to a Microchip LAN7515 controller. This is a factor of ten faster than the previous Pi – at least it will be if the rest of your networking infrastructure supports this. Many home routers don’t support speeds faster than 100 Mbps, but in offices and schools you may get a noticeable speed up.

These new specs give a snappier performance to the Pi as a general computer, and the 17% speed-up on the processor may well be enough on its own to convince people using the Pi as a desktop to part with $35 to upgrade. However, we’re more concerned with what the new Pi means to our makes.

The GPIO connection remains unchanged, so as far as physical connections go, there’s no difference, and any wiring you could do on the previous Pi will still work here.

3B+ pinouts

The extra horsepower will come in useful if you need a computationally intensive brain for your make (image processing or artificial intelligence, for example).

WiFi Channels

WiFi networks run on a ‘channel’ or small range of frequencies within a particular band. Originally, WiFi ran in 14 overlapping 40 MHz channels between 2412 MHz and 2484 MHz. With all the various WiFi networks in the area competing to use this fairly narrow frequency range, there can be quite a lot of interference. In network terms, interference means slow speeds.

Throw in the fact that microwaves and cordless phones also use a similar frequency range and, in a busy area like an office or apartment block, the result can be a dramatic slow down of the network.
The solution to this overcrowding is to open up more frequencies for WiFi networks, and this is where 5 GHz comes in. There’s less demand for frequencies this high, so there are more channels available – 23 non-overlapping channels in fact. This means less overcrowding.

There is a slight complication in that you can’t just double the frequency and expect the properties of the signal to be the same. The biggest difference most people will experience from the different frequencies is that 2.4 GHz is likely to transmit further than 5 GHz. We say likely because there are no hard and fast rules for WiFi range, and it depends on physical objects, atmospheric conditions, and a myriad of other conditions.

Block web adverts with Pi-hole

Make the most of the 3B+’s faster networking


Most people these days run a home network with a router distributing a single internet connection to all their devices, from mobile phones to TVs to computers. Most internet packages come with a router that does all the basics to get your house online. However, you don’t have to blindly use the default settings you get from your internet provider, and with a little of your own infrastructure you can control how your devices access the internet. One such option is to run your own DNS server, such as Pi-hole. While that may not sound that exciting, it does one important thing: it allows you to block web adverts on all your devices with only one setting.

The DNS provider is what converts a domain name (such as hsmag.cc) into the IP address which uniquely identifies the computer that serves up the relevant content for that website. Most internet adverts are served up by domains associated with particular advertising agencies. Pi-hole does this converting of domains to IP addresses normally, except any time a website requests content from a domain flagged as belonging to an advertiser, when Pi-hole simply serves up blank content.
The result is that all devices connected to this network get ad blocking without any additional software needing to be installed.

Given that such a large proportion of internet traffic can be adverts, using Pi-hole can speed up your internet browsing speeds on any Pi. However, the new model should give you DNS results quicker, especially if you live in an area where there’s a lot of traffic on the 2.4 GHz WiFi network.

Other home server options

The low power usage of the Raspberry Pi makes it a great option for a home server and can run a lot more than Pi-hole. A few of our favourites are:


Nextcloud is a suite of tools for collaboration and sharing. There’s email, file synchronisation, web-based document editing (via Collabora Office Online), calendars, and more. All this can run on a Raspberry Pi, and allows you to take control of your own data.

FreeNAS / OpenMediaVault

Network-attached storage (NAS) systems provide shared disk space available to all computers on your network. It’s a little bit like Dropbox or Google Drive but run on computers you control. There are a few options for this on the Raspberry Pi, but FreeNAS and OpenMediaVault are a couple of the most popular.

Web server

You can run most modern web software on a Raspberry Pi, so anything you want to put on the web can probably be run off a Raspberry Pi provided the number of visitors doesn’t go too high. You can even run this from your home network, as long as you set up port forwarding on your router, and use a dynamic DNS system if necessary. If you do make it publicly available though, you’ll need to ensure that you properly secure the Pi to protect your network.

Play games with RetroPie

Use the extra processing power to play games


Most maker projects don’t tax the processor too much, but retro computing is one of the exceptions. Emulating hardware is a complex process, and it can take a surprising amount of computing power to recreate the effects of older hardware. The new Pi’s extra clock speed should give retro-gamers a little more headroom for running older games and adding effects.

Many retro computer emulators are open source and can be compiled on the Raspberry Pi; however the easiest way to get started is with RetroPie. This is a software package (also available as an SD card image) that bundles together emulators for 52 classic games consoles, including the best games system of all time, the Super Nintendo Entertainment System [not the Commodore 64, as has been erroneously reported elsewhere], and gives them an easy to use interface.

You’ll need a controller, and RetroPie can work with most USB game pads, or you can build your own. Essentially, a controller is just a set of buttons and the circuitry needed to translate these into commands that your computer understands (usually via USB). You can build a one-off microcontroller board, or use a specially designed controller such as PetRockBlock’s GamepadBlock, which does most of the work, leaving you to design the housing and attach the buttons.

While it’s not essential to build your system into a period-accurate case – maybe by utilising the casing from an old console, or perhaps an arcade cabinet – it does add a certain extra pleasure to do so.


ROMs and legalities

Playing older games can put you in a legally ambiguous position. While there are vast packs of ROMs (game files) available online, these are usually posted without the copyright-holder’s consent. Legal jurisdictions vary and most of the issues around playing old games exist in a legal grey area of ‘Fair Use’ in copyright law that’s not been tested in court.

You can still play retro-style games without having to worry about the intricacies of copyright law by playing games that have been released for emulators. You can find a wide range of such games at https://pdroms.de.

Perhaps the best technical solution to this legal quandary is to read the games directly from the cartridges. You can get a device called a Retrode, which lets you read console cartridges via USB from dragonbox.de (they were out of stock at the time of writing, but a new shipment should have arrived by the time you read this).

Many old games cartridge connectors are simply address buses to the memory, and you can read in the game data bit-by-bit as you need it. For example, there’s code and circuitry to read SNES roms on a Raspberry Pi here: hsmag.cc/DxWffc.

The most challenging bit is usually physically connecting to the cartridge, as this can often require the original connector desoldered from an old console. This level of hacking can feel a little sacrilegious, but can mean that your game collection will find a new home.


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