We have run out of fruits to name all the single-board computers on the market, but that doesn’t mean you can’t buy a rotten one. Bad documentation, incomplete specifications and deprecated firmwares are just some of the caveats of buying only by price and hardware features. To help you out in case you just need to find a great and open-enough SBC with community support, [Eric] has put together a decent list with 81 individually reviewed boards over at hackerboards.com.
A lot of old science fiction movies show people wearing the same–or nearly the same–clothes. We’re left guessing if this is because there is a single centralized plant mass-producing skin-tight jumpsuits, or if everyone is under orders to dress the same. Now that we live in the past’s future, it looks like science fiction was a poor predictor of fashion. People want variety.
Which calls to mind development boards. How many different ones do we need? Need doesn’t matter, because we have plenty of them. There may be strong leaders: in the 8-bit world, you think of the Arduino, and on the Linux side, maybe the Raspberry Pi. But there are options.
[Eric Brown] recently compared several inexpensive development boards from FriendlyARM including the NanoPi M3, the NanoPi M1, and the NanoPC-T3. These range from about $11 to $60 with the M3 costing $35. You can see an M1 booting on an HDMI screen in the video below.
It’s been a big week in the world of inexpensive single board computers, and everyone’s talking about the new Raspberry Pi 3. It blows away the competition they say, nobody can touch it for the price.
Almost nobody, that is.
With a lot less fanfare on these shores, another cheap and speedy 64-bit quad-core ARM-based SBC slips onto the market this week, Hardkernel’s Odroid C2. And looking at the specification it seems as though the Pi 3 may be given a run for its money. Like the BCM2837 in the Pi 3 its Amlogic S905 SoC is a quad-core ARM Cortex-A53, but the C2’s 2GHz clock speed gives the raspberry to the 1.2GHz of the Pi 3. There is twice the RAM of the Pi 3 at 2Gbytes, and the onboard Mali-450 GPU can deliver 4K video.
Unlike the Pi 3 there is no wireless or Bluetooth on board, but the C2 has a Gigabit Ethernet port which is wired directly into the SoC. Compared to the Pi 3’s 100 megabit port which suffers through being on a USB interface, that’s likely to be very quick.
Storage can be a choice of either the usual micro SD card or eMMC. Given that the two boards share a very similar form factor it is no surprise that they have very similar GPIO capabilities, however it is worth noting that the C2 has a built-in analog-to-digital converter. As to operating systems, the C2 can run Ubuntu 16.04, or Android Lollipop.
Of course, we’ve seen so many boards touted as Pi-killers, and like all those also-ran tablets touted as iPad killers a few years ago we’ve never heard of most of them again after a brief moment of chatter. They look so good on paper but the price always lets them down.
The C2 could just escape that fate though, its $40 price point is very close to that of the Pi 3. Setting aside for a moment how much shipping and customs might cost for a package from Korea, that sounds interesting to us.
Why might you buy a C2 then, and why might you buy a Pi 3? That the C2 has a much faster processor is beyond doubt. This and its faster wired networking would make it a much more interesting prospect for anyone whose work involves network-attached data processing. But even though a USB wireless network adaptor can be had for only a few dollars the Pi 3’s onboard wi-fi and Bluetooth makes it much more attractive to a home user or someone using a computer on a platform unfettered by wires.
However impressive the C2 may be it is overwhelmingly likely that the Pi 3 will outsell it many times over. This will not just be due to the massive publicity advantage achieved by the Pi Foundation, but the huge ecosystem of hardware and software developers that have made the Pi boards perform to the limit of their abilities in all directions. If you don’t mind forgoing that support though, you could just find that the board from Korea gives you enough extra bang for your buck to make having it on your bench worthwhile.
We’ve followed the Odroid products from the start here at Hackaday. The C2 is just the latest of a procession of boards from Hardkernel, and we’ve featured a few projects that include them. Theirs is always the name at the top of the list when the subject turns to Raspberry Pi competitors, perhaps with the C2 they’ve got a winner.
Our thanks to [Derrick].
Robots have always been a wonderful tool for learning electronics, but if you compare the robot kits from today against the robot kits from the 80s and early 90s, there’s a marked difference. There are fairly powerful microcontrollers in the new ones, and you program them in languages, and not straight machine code. Given this community’s propensity to say, ‘you could have just used a 555,’ this is obviously a problem.
[Carbon]’s entry for The Hackaday Prize is a great retro callback to the Heathkit HERO and robotic arms you can now find tucked away on a shelf in the electronics lab of every major educational institution. It’s a 65C02 single board computer, designed with robotics in mind.
The 6502 board is just what you would expect; a CPU, RAM, ROM, CPLD glue, and a serial port. The second board down on the stack is rather interesting – it’s a dual channel servo board made entirely out of discrete logic. The final board in the stack is an 8-channel ADC meant for a Pololu reflective sensor, making this 6502 in a Boe-bot chassis a proper line-following robot, coded in 6502 assembly.
[Carbon]’s video of his bot below.
The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.
Where homebrew computers are usually complex bundles of wires and chips, [Mike]’s own single board computer is not. It’s a three-chip computer with only a CPU, RAM, and a microcontroller that is able to emulate the retrocomputers of yore.
Normally, a homebrew computer project requires some amount of ‘glue’ logic – a few NAND, OR, or inverters to combine signals and send them where they’re needed for address decoding. This tiny pocket computer doesn’t need any of that; all the address decoding is done on a 40-pin PIC microcontroller.
With 64kB on the PIC 18F46K22, there’s enough space for all the address decoding logic, space for a pseudo ACIA mapped onto the $DF page, and a ROM image that provides a monitor program and a copy of BASIC. Basically, with the addition of a USB to serial adapter, this is a three chip 6502 single board computer, and with the right ROM monitor can emulate an Apple I, Woz monitor included.
Yes, 6502 projects are a dime a dozen, but [Mike]’s work with the address decoding logic on the microcontroller is top-notch. There are a few remaining chip select lines in his schematic, and with another microcontroller it would be easy to add VGA out, a compact flash adapter, or some other really cool peripherals. Good thing there’s an expansion port on this thing.