When You Need a Scope, You Need a Scope

Sometimes there’s just no substitute for the right diagnostic tool. [Ankit] was trying to port some I2C code from an Arduino platform to an ARM chip. When the latter code wasn’t working, he got clever and wrote a small sketch for the Arduino which would echo each byte that came across I2C out to the serial line. The bytes all looked right, yet the OLED still wasn’t working.

Time to bring out the right tool for the job: a logic analyzer or oscilloscope. Once he did that, the problem was obvious (see banner image — Arduino on top, ARM on bottom): he misunderstood what the ARM code was doing and was accidentally sending an I2C stop/start signal between two bytes. With that figured, he was on the right track in no time.

We just ran an epic post on troubleshooting I2C, and we’ll absolutely attest to the utility of having a scope or logic analyzer on hand when debugging communications. If you suspect that the bits aren’t going where they’re supposed to, there’s one way to find out. It’s conceivable that [Ankit] could have dug his way through the AVR’s hardware I2C peripheral documentation and managed to find the status codes that would have also given him the same insight, but it’s often the case that putting a scope on it is the quick and easy way out.

The Perfect Storm: Open ARM + FPGA Board

Playing around with FPGAs used to be a daunting prospect. You had to fork out a hundred bucks or so for a development kit, sign the Devil’s bargain to get your hands on a toolchain, and only then can you start learning. In the last few years, a number of forces have converged to bring the FPGA experience within the reach of even the cheapest and most principled open-source hacker.

[Ken Boak] and [Alan Wood] put together a no-nonsense FPGA board with the goal of getting the price under $30. They basically took a Lattice iCE40HX4K, an STMF103 ARM Cortex-M3 microcontroller, some SRAM, and put it all together on a single board.

The Lattice part is a natural choice because the IceStorm project created a full open-source toolchain for it. (Watch [Clifford Wolf]’s presentation). The ARM chip is there to load the bitstream into the FPGA on boot up, and also brings USB connectivity, ADC pins, and other peripherals into the mix. There’s enough RAM on board to get a lot done, and between the ARM and FPGA, there’s more GPIO pins than we can count.

Modeling an open processor core? Sure. High-speed digital signal capture? Why not. It even connects to a Raspberry Pi, so you could use the whole affair as a high-speed peripheral. With so much flexibility, there’s very little that you couldn’t do with this thing. The trick is going to be taming the beast. And that’s where you come in.

New Part Day: ST’s 32-Bit 3D Printer Controller

There are a few 32-bit ARM-based 3D printer controller boards out there such as the Smoothieboard, the Azteeg X5 mini, [Traumflug]’s Gen5 electronics, whatever board is in the Monoprice MP Mini Select, and several others I will be criticized for not mentioning. All of these ARM boards provide smoother acceleration, better control, and ultimately better prints from whatever 3D printer they’re controlling. Now, out of the blue, there’s a new board. It’s an evaluation board from ST — much like those famous Discovery boards — that sells itself as a plug and play solution for 3D printers.

The heart of this board is an STM32F401 — not the king of the STM32 line or the fastest ARM microcontroller, but anything faster or more capable will add considerably more to the BOM for this board. This controller board features six of ST’s L6474 motor drivers with enough current for some beefy NEMA 23 stepper motors , a multi-zone heated bed, and connections for a WiFi module and external LCD and keypad. You can buy this board right now for $118. This board isn’t a game changer, but it is evidence the game has been changed.

As with all 3D printer controller boards, there are a few aspects that will leave users wanting more. This is a board meant for 12V heaters (except for the bed, which has a 24V, 20A output), and the stepper drivers can only go up to 16 microsteps. That said, there’s not much else to complain about. This offering comes with a 32-bit firmware called Marlin4ST. From a quick perusal, it looks like the familiar configuration.h is still there, and still does what it’s supposed to do.

This ST Discovery board is extremely capable, available now, and relatively cheap, but that’s not really the big story here. What this board represents is a reference design and working firmware for a 32-bit ARM-based printer controller. That’s the future, and with this board the future might come a little sooner.

Thanks [jagerboots] for sending this one in.

SoftBank Bought ARM

$32 billion USD doesn’t buy as much as it used to. Unless you convert it into British Pounds, battered by the UK’s decision to leave the European Union, and make an offer for ARM Holdings. In that case, it will buy you our favorite fabless chip-design company.

The company putting up 32 Really Big Ones is Japan’s SoftBank, a diversified technology conglomerate. SoftBank is most visible as a mobile phone operator in Japan, but their business strategy lately has been latching on to emerging technology and making very good investments. (With the notable exception of purchasing the US’s Sprint Telecom, which they say is turning around.) Recently, they’ve focused on wireless and IoT. And now, they’re going to buy ARM.

We suspect that this won’t mean much for ARM in the long term. SoftBank isn’t a semiconductor firm, they just want a piece of the action. With the Japanese economy relatively stagnant, a strong Yen and a weak Pound, ARM became a bargain. (SoftBank said in a press release that the Brexit didn’t affect their decision, and that they would have bought ARM anyway. Still, you can’t blame them for waiting until after the vote, and the fallout, to make the purchase.) It certainly won’t hurt SoftBank’s robotics, IoT, or AI strategies to have a leading processor design firm in their stable, but we predict business as usual for those of us way downstream in the ARM ecosystem.

Thanks [Jaromir] for the tip!

Another Small Linux Computer With Pi In Its Name

Since the introduction of the Raspberry Pi, the embedded Linux scene has been rocked by well supported hardware that is produced in quantity, a company that won’t go out of business in six months, and a huge user base. Yes, there are a few small problems with the Raspberry Pi and its foundation – some stuff is still closed source, the Foundation itself plays things close to their chests, and there are some weird binary blobs somebody will eventually reverse engineer. Viewed against the competition, though, nothing else compares.

Here’s the NanoPi Neo, the latest quad-core Allwinner board from a company in China you’ve never heard of.

The NanoPi Neo is someone’s answer to the Raspberry Pi Zero, the very small and very cheap single board Linux computer whose out-of-stock percentage has led some to claim it’s completely fake and a media conspiracy. The NanoPi Zero features an Allwinner H3 quad-core Cortex-A7 running at 1.2 GHz, 256MB RAM, with a 512MB version being released shortly. Unlike the Raspberry Pi Zero, the NanoPi Neo features a 10/100 Ethernet port. No, it does not have PoE.

As with anything comparing itself to the Raspberry Pi Zero, only two things are important: size and price. The NanoPi Neo is a mere 40mm square, compared to the 65x30mm measurements of the Pi Zero. The NanoPi Neo is available for $7.99, with $5 shipping to the US. Yes, for just three dollars more than a Pi Zero with shipping, you get a poorly supported Linux board. What a time to be alive.

If you’re looking for another wonderful tale of what happens with cheap, powerful ARM chips and contract manufacturers in China, check out my review of the Pine64.

Hackaday Prize Entry: MiniSam-Zero

Thanks to the Arduino, Atmel’s SAM line of ARM microcontrollers are seeing a lot of use as 32-bit learning tools. For his Hackaday Prize project, [Jeremey] is using one of these chips without all the Arduino drama. He’s built a tiny Atmel SAM dev board that’s cheap, simple, and interestingly for a 32-bit ARM board, easy to program.

For this board, [Jeremy] is using Atmel’s SAM D09, the smallest member of the family that also includes the chip on the new Arduino Zero and the Arduino M0 (built by the other Arduino). The MiniSam-Zero uses a slightly smaller chip with 8 kB of on-chip Flash. Eagle-eyed complainers will notice the SAM D09 does not have internal EEPROM, so an EEPROM is added on-board. Also on board is a temperature sensor and a Silicon Labs CP2102 for serial communications.

That last chip – the Serial USART – allows for a rather interesting build if the firmware is done right. Instead of futzing about with ARM SWD while programming the device, a serial bootloader would allow anyone to plug a USB cable into this board and upload code straight from an IDE. This is perhaps the coolest feature of the MiniSam-Zero, and something [Jeremy] has worked tirelessly to get right. He can upload directly from Atmel Studio, and after a bit more work, [Jeremy] will be able to program this board directly from the Arduino IDE. That’s great work, and although this board isn’t as capable as other ARM microcontroller offerings, it’s still a fantastically useful device.

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Cracking The Sega Saturn After 20 Years

When it was released 20 years ago, the Sega Saturn was by far the most powerful video game console available. It was a revolutionary device, had incredible (for the time) graphics, and a huge library of IP Sega could draw from. The Saturn was quickly overshadowed by the Sony Playstation, and soon these devices found themselves unused, unloved, and fetching high prices on the collectors market.

After finding a Sega Saturn on a trip to Japan, [jhl] decided he would like to write some code for this machine. Unlike earlier consoles, where Flash cartridges are readily available, or later consoles, where writing directly to the on-board storage is easy, bringing up a development environment for the Saturn isn’t easy. The best method is installing a mod chip and working off of burned CDs. Instead of writing a game or two for the Saturn, [jhl] got distracted for a few years and developed an optical drive emulator.

cracking-the-sega-saturn-thumbAccording to [jhl], the design of the Sega Saturn is tremendously complicated. There’s an entire chip dedicated to controlling the CD drive, and after some serious reverse engineering work, [jhl] had it pretty much figured out. The question then was how to load data onto the Saturn. For that. [jhl] turned to the internal expansion port on the Saturn. This internal expansion port was designed to accept an MPEG decoder card for playing video CDs on the Saturn, but the connector presents the entire bus. By attaching a Game Boy Flash cartridge, [jhl] was able to dump the ROM on the CD controller.

With a little bit of work, a fast ARM microcontroller, and a CPLD for all the logic glue, [jhl] was built an adapter to push CD data to the Saturn through this internal expansion port. Not only is this a boon for homebrew Saturn development, but this build also completely replaces the CD drive in the Saturn – a common failure point in this 20-year-old machine.

The formal release for this ultimate Saturn crack isn’t out yet, but it’s coming shortly, allowing anyone who still has a Saturn to enjoy all those very blocky games and develop their own games. You can check out a short, amateur documentary made on [jhl]’s efforts below.

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