An updated Raspberry Pi board was released earlier this month, and the kind folk at Element 14 sent me one to review.
The Raspberry Pi is a complete low-power computer which needs only a case, an SD card, and a standard USB power source to start doing real work. It is ideal for learning projects, home automation, practical applications like running a media server or client, or anything you can think of.
It is a little over two years since the first Pi was shipped in April 2012. The progress is a little confusing: the first model was the B, followed by the A in early 2013, a cut-down model with a single USB port and no Ethernet.
The new model has the same Broadcom BCM2835 SoC as all the other Pi models. The CPU is a 700 MHz ARM 1176JZ-F.
So what is new? The highlights:
- 4 USB 2.0 ports
- The dedicated composite video port has been removed and is now shared with the audio jack, requiring an adaptor
- The power draw is now 600 mA up to 1.8A at 5v, making it both lower power and higher power (when necessary) than the model B (750 mA up to 1.2A at 5v). The USB ports can supply a little more power, making most self-powered external hard drives usable, for example.
- The SD card slot has been replaced by a micro SD card slot, a good move (all my SD cards are in fact micro SD cards with adaptors, which is common).
- The GPIO (General Purpose Input Output) connector now has 40 pins rather than 26. The first 26 pins are the same as before, for compatibility.
- The price is the same as for the B
There are a few other changes which I noticed. One is that the LEDs have been moved. On the B, there are 5 LEDs which are together on the bottom right corner of the board: ACT (SD card access), PWR, FDX (Duplex LAN), LNK (Activity LAN) and 100 (100Mbit LAN connected). The B+ has two LEDs in the opposite corner, ACT and PWR, and two more LEDs on the LAN port itself. Personally I prefer the old arrangement.
The audio output is improved, according to Pi inventor Eben Upton, thanks to a “dedicated low-noise power supply.” Raspberry Pi Engineer jdb adds that “The output impedance and buffering for the audio port has been improved and the maximum output amplitude has been increased (~1.25V pk-pk).” However one blogger measured the output and considered no better (or slightly worse).
Since the layout of the board has changed, a B+ Pi will not fit in your old model B case. I bought a new case but I don’t recommend this one:
This is a push-fit case and even thought the board is held down by tabs, it moves and rattles slightly. I also worry about the case tabs breaking if you open it repeatedly. The tab that you need to press to open the case is sited by the micro SD slot, and that is another mistake, since it presses against the board making it hard to reopen after the Pi is fitted. There is also too much space below card slot so you can easily post your card into the case rather than into the slot if you are careless. Finally, I don’t like the way the top of the case slopes down, reducing the space above the GPIO at its shallow point.
I wish I had seen this Cyntech case which looks miles better, for a similar low price, though I haven’t actually tried it. I do like the idea of an optional spacer which lets you increase the case height to fit add-on boards.
Finally, a few notes on operation. If you have existing micro SD cards running on the B, they might or might not work on the B+. I use piCorePlayer as a streaming audio client, for which it is excellent, but my existing image would not boot on the B+. Following a tip elsewhere, I installed the latest piCorePlayer download on the B, updated it to version 1.16A using the web UI, and it then worked on the B+.
I had no such problems with the standard Raspbian distro which worked fine on the B+.
So do you need the B+? If you have not yet tried a Pi, give it a try, it is fabulous. If you already have a B, then you will find some nice improvements but nothing dramatic – though the extra USB ports in particular are most welcome.