Tag Archive for SiFive

Custom PC, Issue 189

Custom PC Issue 189This month, my regular Hobby Tech column opens with a look at a RISC-V based not-quite-off-the-shelf personal computer build by AB Open, walks readers through building a weather monitor powered by a Raspberry Pi and a Pimoroni Unicorn HAT, and marvels at the excesses of the computer retail scene in the 1970s and 1980s via David Pleasance’s Commodore: The Inside Story.

First, the PC. The majority of PCs on desks around the world today are based on processors which use the x86 architecture or its 64-bit equivalent; a small handful are based on similar Arm chips to the ones you might find in your smartphone; and an even smaller number are powered by things like Zilog Z80s, MOS 6502s, and Motorola 68000s belonging to people who just don’t like to throw away a perfectly good decades-old system. The system built by AB Open recently, though, is different: it’s based on RISC-V, an open instruction set architecture (ISA) for which anyone can – given time, money, and a fair smattering of expertise – build a chip.

“It might be some time before there’s an off-the-shelf chip that can compete with x86 on raw performance and traditional benchmarks,” AB Open’s Andrew Back, who for full disclosure is a client of mine, admits, “but the open nature of the ISA, and the ecosystem developing around it, is driving a renaissance in novel computer architectures.” By way of proof: a fully-functional Linux-based desktop PC, built in a custom-designed laser-cut chassis, created using the SiFive HiFive Unleashed development board and Microsemi expansion board.

From a PC you can browse the web on to one which flashes a few lights: the Raspberry Pi weather monitor is a remix of a project I published in Issue 153, to use a Pimoroni Unicorn HAT LED matrix to graph energy usage in my home. This time, the same hardware is repurposed to show animated weather icons based on data downloaded from OpenWeatherMap – and, despite the low resolution of the LED matrix, it works an absolute treat.

Finally, Commodore: The Inside Story sounds like it should be an exhaustive history of the company behind one of the world’s biggest-selling home computers. It isn’t. Instead, it’s a two-part affair: the first is a series of personally recollections, presented in a very similar fashion to the stories you might hear if you took author David Pleasance to the pub and asked him about his time working in Commodore’s sales and marketing division; the second is a collection of guest chapters, and as fun as it is reading about orgies in Consumer Electronics Show hotels and drink-driving incidents the second half is, for me, the better half.

All this, and a raft more, can be found at your nearest newsagent or supermarket; the electronic version, meanwhile, is enjoying a brief holiday while background administration relating to its recent switch of publishers takes place.

Custom PC, Issue 164

Custom PC Issue 164My Hobby Tech column this month is dominated by two reviews of devices which have taken their inspiration from better-known alternatives, but the two couldn’t be more different: the Asus Tinker Board and the SiFive HiFive1. As an added bonus, there’s a look into the wonderful world of hobbyist pinball machine repair, and by that I mean a friend and I repaired some pinball machines and lived to tell the tale.

First, the Tinker Board. There have been rumours flying around since last year that Taiwanese technology giant Asus was looking to carve itself off a slice of the Raspberry Pi pie, and that’s exactly what the Tinker Board is: an attempt to clone the Raspberry Pi. Its footprint and layout are so close to the original that it’s entirely possible to use official Raspberry Pi cases without difficulty, and the features available are a one-for-one match: four USB ports, an Ethernet port, Bluetooth and Wi-Fi, a 3.5mm jack, CSI and DSI connectors, and even the Pi’s trademark 40-pin GPIO header.

To its credit, Asus has tried to improve upon the original design. The processor is more powerful – quite impressively so, I discovered in my testing – and purportedly supports 4K video playback, the Ethernet supposedly gigabit, there’s support for 24-bit 192KHz high-definition audio, the RAM has been boosted from 1GB to 2GB, and the GPIO port has received colour coding to its pins. Sadly, many of these claims fell short during testing: the Ethernet port’s throughput is sub-100Mb/s even when connected to a gigabit switch, the 4K video playback simply doesn’t work, and the GPIO port is useless for anything save basic on-off pin switching – there’s no I²C, no SPI, no 1Wire, no UART, nothing, with all advanced features simply listed as in-the-works.

The SiFive HiFive1, by contrast, delivers on its promises and more. Designed to mimic the footprint and layout of an Arduino Uno microcontroller, the HiFive1 is notable for the chip at its heart: one of the first off-the-shelf implementations of the open-source RISC-V (pronounced “risk five”) architecture. Still in its relative infancy compared to Atmel’s AVR or Intel’s x86 architectures, RISC-V is designed to scale from microcontrollers like SiFive’s through to high-efficiency server systems.

Like the Tinker Board, I ran into a few hiccoughs during testing. Unlike the Tinker Board, they were all quickly addressed. Considering the HiFive1 is only the second major product from SiFive and is the first commercial implementation of the RISC-V architecture to include support in the Arduino IDE for easy programming, I was thrilled with the board – and sad when my time with it came to an end.

Finally, pinball machines. The last page of this month’s column details my visit to the Brew Haus in Bradford with my friend Stuart Childs, but rather than being there for the beer we were there to administer some love to a series of pinball machines the owner had recently installed – one of which, a Data East Star Wars table, was entirely non-functional and missing its keys to boot. Between picking the lock to gain entry, replacing the somehow-shattered bumpers, testing the electronics, and discovering the PSU was hanging by a thread – its screws, interestingly, being attached to the magnet of a nearby speaker – a fun time was had and a working table set up by the end of the evening.

To get the full low-down on all these topics, plus a whole lot of interesting stuff written by people who aren’t me, head to your local newsagent, supermarket, or other magazine outlet, or pick up a virtual copy via Zinio or similar digital distribution services.