Arduino On MBed

August 30, 2019 by Al Williams 22 Comments

Sometimes it seems like Arduino is everywhere. However, with a new glut of IoT processors, it must be quite a task to keep the Arduino core on all of them. Writing on the Arduino blog, [Martino Facchin], Arduino’s chief of firmware development, talks about the problem they faced supporting two new boards from Nordic.

The boards, the Nano 33 BLE and Nano 33 BLE Sense are based on an ARM Cortex M4 CPU from Nordic. The obvious answer, of course, is to port the Arduino core over from scratch. However, the team didn’t want to spend the time for just a couple of boards. They considered using the Nordic libraries to interact with the hardware, but since that is closed source, it didn’t really fit with Arduino’s sensitivities. However, in the end, they took a third approach which could be a very interesting development: they ported the Arduino core to the Mbed OS. There’s even an example of loading a sketch on top of Mbed available from [Jan Jongboom].

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Debug Superpowers Bring An STM32 Back From The Dead

August 26, 2019 by Kerry Scharfglass 5 Comments

When a processor has a fault it can leave what looks to be precious little in the way of cause and effect. Debug-by-print-statement works surprisingly well in simple cases, but where in a desktop environment you would drop into a debugger to solve trickier problems this can be an onerous task on an embedded system. [Ross Schlaikjer]’s excellent blog post walks through setting up one of our favorite Open Hardware debug probes and shows us that with the right tooling in place, unexpected faults aren’t quite so impenetrable. Continue reading “Debug Superpowers Bring An STM32 Back From The Dead” →

A New KiCAD Tutorial Hits The Scene

July 29, 2019 by Kerry Scharfglass 42 Comments

KiCAD has a rightfully earned image problem regarding beginners. The shiny new version 5 has improved things (and we’re very excited for v6!) but the tool is a bit obtuse even when coming from a electronics design background, so we’re always excited to see new learning material. [Mike Watts] is the latest to join the esteemed group of people willing to export their knowledge with his KiCAD tutorial series on GitHub that takes the aspiring user from schematic through fab and assembly.

The tutorial is focused around the process of creating a development board for the dimuitive Microchip née Atmel ATSAMD10 Cortex M0 ARM CPU. It opens by asking the reader to create a schematic and proceeds to teach by directing them to perform certain actions then explaining what’s going on and which shortcuts can accelerate things. This method continues through layout, manufacturing, and assembly.

Of note is that when defining the board outline [Mike] describes how to use OpenSCAD to parametrically define it; a neat micro-tutorial on using the two great tools to compliment each other. We also love that upon successful completion of the tutorial series the user will have developed a tiny but useful development board that can be assembled for about $3 in single quantities!

As with all open source work, if you have quibbles or want to contribute open a pull request and give [Mike] a hand!

Building A Development Board For The STM32 G0 Series

July 16, 2019 by Maya Posch 30 Comments

When [Andy Brown] recently tripped over ST’s new G0 series of MCUs, he figured after some research that the best way to learn everything there’s to know about the STM32G0xx by making his own development board based around the STM32G081. The result is a Nucleo-style board, breaking out all pins to convenient 2.54 mm headers, and with a number of niceties, such as an on-board coin cell and 32.768 kHz LSE oscillator for RTC use and three different power supplies (3.3 V, 2.5 V, and 1.8 V) for the MCU.

The board is programmed with an external ST-Link programmer that connects to the SWD interface on the MCU, with a 20-pin programming header provided. While by no means small or compact, it makes for very easy breadboarding and prototyping, with all 2.54 mm headers accessible from the bottom and top.

As for the STM32G0 series itself, the jury is still out on its performance compared to the F0. The former swaps the Cortex-M0 core for an M0+, with a reduced pipeline length (3 stages in the G0) but increased frequency (64 MHz versus 48 MHz). The G0 has a little bit more SRAM, but so far less Flash storage. According to ARM, this MCU range is designed to remove any need to still use an 8-bit MCU. Big claims, indeed.

The biggest issue which [Andy] had while developing this board was probably with the CH340 USB-UART chip. Ordering them from AliExpress as is common, the CH340G ICs he got just wouldn’t work on the first board revision, forcing him to switch to the CH340E and requiring a board respin. This version has an internal oscillator and as a bonus even came in the original tape packaging when it arrived, instead of in a plastic baggy like with the CH340G parts.

See a video of [Andy] going through the design after the break.

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Bringing PalmOS Back To Life

May 21, 2019 by Bryan Cockfield 36 Comments

Ten years is almost ancient history in the computing world. Going back twelve years is almost unheard of, but that’s about the time that Palm released the last version of their famed PalmOS, an operating system for small, handheld devices that predated Apple’s first smartphone by yet another ten years. As with all pieces of good software there remain devotees, but with something that hasn’t been updated in a decade there’s a lot of work to be done. [Dmitry.GR] set about doing that work, and making a workable Palm device for the modern times.

He goes into incredible detail on this build, but there are some broad takeaways from the project. First, Palm never really released all of the tools that developers would need to build software easily, including documentation of the API system. Since a new device is being constructed, a lot of this needs to be sorted out. Even a kernel was built from scratch for this project, since using a prebuilt one such as Linux was not possible. There were many other pieces of software needed in order to get a working operating system together running on an ARM processor, which he calls rePalm.

There are many other facets of this project that we aren’t able to get into in this limited space, but if you’re at all interested in operating systems or if you fondly remember the pre-smartphone era devices such the various Palm PDAs that were available in the late ’90s and early ’00s, it’s worth taking a look at this one. And if you’d like to see [Dmitry.GR]’s expertise with ARM, he is well-versed.

Thanks to [furre] for the tip!

Rad-Hard ARM Microcontrollers, Because Ceramic Components Are Just Cooler

April 13, 2019 by Brian Benchoff 57 Comments

If you’re building a cubesat, great, just grab a microcontroller off the shelf, you probably don’t need to worry about radiation hardening. If you’re building an experiment for the ISS, just use any old microcontroller. Deep space? That’s a little harder, and you might need to look into radiation tolerant and radiation hardened microcontrollers. Microchip has just announced the release of two micros that meet this spec, in both radiation-tolerant and radiation-hardened varieties.

The new devices are the SAMV71Q21RT (radiation-tolerant) and the SAMRH71 (rad-hard), both ARM Cortex-M7 chips running at around 300 MHz with enough RAM to do pretty much anything you would want to do with a microcontroller. Peripherals include CAN-FD and Ethernet-AVB, analog front-end controllers, and the usual support for I2C, SPI, and other standards. This chip does it in space, and comes in a ceramic quad flat package with gold lead frames. These are beautiful devices.

Microchip has an incredible number of space-rated, rad-hard hardware; this is mostly due to their acquisition of Atmel a few years ago, and yes, it absolutely is possible to build a rad-hard Arduino Mega using the chip, space rated.

Of course, there are very, very, very few people who would actually ever need a rad-hard microcontroller; I would honestly expect this to be relevant to only one or two people reading this, and they too probably got the press release. If you’ve ever wanted to build something that goes to space, and you’d like to over-engineer everything about it, you now have the option for an ARM Cortex-M7.

Quadcopter Uses Bare Metal STM32

March 11, 2019 by Al Williams 7 Comments

[Tim Schumacher] got a Crazepony Mini quadcopter and has been reprogramming it “bare metal” — that is to say he’s programming the STM32 without using an operating system or do-it-all environment. His post on the subject is a good reference for working with the STM32 and the quadcopter, too.

If you haven’t seen the quadcopter, it is basically a PC board with props. The firmware is open source but uses the Keil IDE. The CPU is an STM32 with 64K of program memory. In addition, the drone sports a wireless module, a digital compass, an altimeter, and a gyro with an accelerometer.

Although the post is really about the quadcopter, [Tim] also gives information about the Blue Pill which could be applied to other STM32 boards, as well. On the hardware side, he’s using a common USB serial port and a Python-based loader.

On the software side, he shows how to set up the linker and, using gcc, control output ports. Of course, there’s more to go to work the other peripherals, and Tim’s planning to investigate CMSIS to make that work easier. Our earlier post on STM32 prompted [Wassim] over on Hackaday.io to review a bunch of IDEs. That could be helpful, too.