Hitting the electric race track with Atmel MCUs

Written by Stuart Cording

Motorsport: the smell of fuel and oil, permanently in the air; highly-tuned, multi-cylinder engines radiating heat; and the incessant drone and whine, earsplitting at times, as cars come tearing around the track.

None of which you will experience at a race where municHMotorsport e.v. is competing with the PWe4.13, its latest high-performance, all-electric Formula Student Car. The team, comprised of students from the Fachhochschule München, Germany, has many successes behind them and grand plans for the upcoming season which kicks-off summer 2014. The vehicle has an impressive array of specifications, including: acceleration 0-100km/h of <4 seconds; top speed of 110km/h; single-piece monocoque body; and two 60kW electric motors.

The team competes in “Formula Student Germany” which defines the rules and provides the infrastructure for the racing events. Other countries have similar organizations allowing teams to compete all across the world. Electric vehicles have been included as a category for the last four years, perhaps reflecting not only the raised level of interest in “green technologies” but also the maturity and low price-of-entry for the technology needed to build an all-electric racing vehicle.

Racing against one-another is considered too dangerous for self-built vehicles and amateur drivers selected from the available teams. Thus, the competition focuses on areas such as vehicle acceleration, maneuverability and endurance. In 2012 the team suffered a bitter blow in the 22km (13.6 miles) endurance test as the vehicle rolled to a halt just 100m (330 feet) from the finish line. In 2013, however, they bounced back delivering a first place in the Spanish competition in Barcelona. The season ended with the team ranked number 5 worldwide in the electric vehicles category.

Atmel has provided the Control/Electrical System department with ATmega32M1 automotive microcontrollers to support them in their efforts this year. The MCU was selected to fulfill two applications in the vehicle. One MCU sits snugly in the carbon-fiber steering wheel, where control switches and LEDs provide the driver interface, controlled by the on-chip CAN interface. Meanwhile, the second MCU functions as an aggregator for many of the analogue sensors built into the vehicle. Information, such as wheel rotation and tire temperature, are collected and forwarded to one of the vehicle’s four CAN networks.

Like any racing team, telemetry data during testing and racing is essential for the team to understand how and where to improve the vehicle.

Talking to Maximilian Werner (Sponsoring) and Christian Schenk (Teamleader Control & Electrical Systems), the two described the project as a never ending search toward the perfect solution. As this year’s vehicle sits on the starting grid, a new group of students will join the team and the graduates will leave, meaning that valuable knowledge and know-how will have to be passed on if the team is to remain successful.

The team is also made up of cross-discipline students, with electronics and mechanical engineers focusing mainly on design and construction and business studies students undertaking marketing, sponsoring and cost analysis roles.

As I leave the electronics development team behind, we cast an eye over what the mechanical design group is doing.

The smell of glue and epoxy wafts over me as students fill moulds with carbon-fiber matting, sand surfaces to perfection and let finished parts cure. Six crushed nose cones hang on the wall. Maximilian explains that they are proof positive that the car is not only fast, but safe – the result of the mandatory crash testing required before participating.

From left to right: Maximilian Werner (Sponsoring); Andreas Welzmiller (Team Leader High-Voltage System); Tanja Elischer (Media/PR); Fabian Sengl (Braking Lights/TSAL); Manfred Brandstetter (Energy Recuperation); Christian Schenk (Team Leader Control & Electrical Systems)

I am left feeling amazed at the immense focus, drive and passion of a group of people, determined to do their best and deliver at every event. We wish them all the best for the coming season and hope they are first to cross the finish line at every event.

Video: Drawing schematics with Paul Rako

In this episode of Atmel Edge, Analog Aficionado Paul Rako describes the importance of drawing schematics with inputs on the left and top, as well as outputs on the right and bottom.

“The most fundamental thing about a system-level schematic is that there is a flow to it – and that flow is from left to right and from top to bottom,” Rako explains.

“Anyone can pick it up and they know they can look at the left edge and tend to see inputs, or look at the top and tend to see inputs. Then they can look to the right edge or the bottom and tend to find outputs.”

Well, perhaps it isn’t that simple, says Rako, because what about a bus?

“How do you represent something that has bidirectional flow? Do you put things on the top or the left edge? That’s kind of a style, but if you just stick to these basics, you’ll be a lot better off,” he adds.

Watch as Paul provides a little bit higher level tip than just grounds, capacitors and resistors, plus topics we’re going to discuss in the 101 series. Stay tuned!

Video: Atmel’s Paul Rako talks CE and FCC testing

In this episode of Atmel Edge, Analog Aficionado Paul Rako discussed three clever tricks to keep your high-speed circuit boards from radiating energy and failing CE or FCC testing.

Flip your planes, stitch around the edges, or bring the power and ground planes really close together to keep them from oscillating and pumping RF out the edges. These three quick PCB layout tricks will help you pass FCC emissions in no time!

More specifically, says Rako, you take inner plane layers on a four-layer board (or more), bringing them to the outside, effectively creating a containment vessel that prevents radiation from escaping. 

The second?

“Istvan Novak works at [Oracle] Sun Microsystems,” Rako explains. “He says there is prior art; he didn’t invent it, but he figured out you could stitch RCs all around the edge, and that would keep the radiation from not only leaking out, but from bouncing back in.”

As for the third trick, if you go cut up power planes, you can ultimately bring them very close together.

“You can bring them close together and use other planes to contain the RF – distributing your power and ground with intimate one-mil spacing between the planes. That brings the same kind of damping in as the other trick with putting RCs around the edge,” he adds. “So those three tricks are ways to get you through FCC and CE immunity testing.”

Interested in learning more? You can watch the full video here.

Atmel-powered AT-501 heads to EMEA

Arrow Electronics and ShiraTech will be bringing the jointly developed, Atmel-powered AT-501 system-on-module to customers in Europe, Middle East and Africa.

“Combining a system-on-module with comprehensive development tool and software support eases the design process and reduces the development costs,” said Jacko Wilbrink, senior product marketing director, Atmel Corporation.

“These advances are critical for Arrow’s customer base.”

The AT-501 is built around Atmel’s ARM-based SAMA5D3 Cortex-A5 system on chip. According to a ShiraTech rep, the platform offers an optimal balance of the most power efficient Cortex A to date with a high performance CPU running at 536 MHz and a floating point unit.

The AT-501 is designed as a ready-to-use embedded control and processing module for applications such as medical and industrial devices, with low power consumption making the platform especially suited for battery-powered appliances.

Additional key AT-510 specs and features include:

• Controller module – Ready to use embedded control and HMI module.
• Low power consumption – SoC power consumption less than 200mW @536Mhz with all peripherals activated; supports multiple power efficiency modes.
• Extensive connectivity – Equipped with GE with IEEE1588, FE, multiple CAN, UART, SPI and I2C interfaces.
• Display and touch screen – Graphic LCD TFT controller scaling to 1280×720 pixels, resistive touch screen support.
• Software
 – Integrated Linux OS from ShiraTech or Timesys corporation.

Interested in learning more about the Atmel-powered AT-501 system-on-module? You can check out the official product page here. Readers may also want to browse a detailed breakdown of recent Atmel-powered industrial boards and platforms here.

The new Atmel-ICE debugger is here

I ordered the new Atmel ICE debugger as soon as it appeared on the company store. I see there is still stock so feel free to put in an order with us or your favorite distributor. Don’t get this new one confused with our JTAGICE3,  sometimes called JTAGICE markIII or mk3. It looks similar, but this new one has two debugging connectors. One is for the AVR microcontrollers, and one is for ARM MCU devices. There is a nice slide-show and explanation on our Norway site.

The new Atmel-ICE is white and has two connectors for debugging. The old JTAGICE3 (inset) is silver and only has one connector, although you can upgrade the firmware so it can debug SAM D20 ARM-based MCUs.

Best yet, just like we lowered the priced between the JTAGICE2 and JTAGICE3, we lowered it again for the Atmel ICE. You can get the fancy high-zoot version for 85 bucks. It has the pretty box and all the cables. Then there is a stripper version with just one debug cable for $49. Finally, you can get a bare-board version with no case or cables for a measly $32. This is a great deal when you think that a JTAGICE2 was $399.

This new Atmel-ICE replaces both the Dragon and the JTAGICE3. The only other ARV debugger you might need is the AVRONE! debugger that has trace capability. It’s 600 bucks, but that is worth every penny if you are trying to figure out where your program went or how it entered a subroutine or interrupt vector.

For the “big iron” ARM MPU (microprocessor units) with external memory you can use the SAM ICE. The SAM-ICE is in our store for 100 dollars. This works with Atmel’s MPU chips like the ARM Cortex A5-based chips like the SAMA5D series, and the ARM9-based SAM9x parts.

I unboxed my new Atmel-ICE today, here are the pictures:

The box has a Norse warrior on it, as tribute to the brilliant Norwegian engineers that invented the AVR chip.

Open the box and you see the Atmel-ICE on the left, safely snuggles in anti-static foam, and a box on the right with the three cables and breakout PCB.

Here is a close-up of the debug connectors. Identical, but the one on the right is for AVR and the one on the left is for ARM-based MCUs.

The Atmel ICE uses the micro USB connector. The two more expensive versions come with the cable, the bare PCB does not.

To keep costs down we didn’t paint the logo on, you can see it is nicely inset, as are the “AVR” and “SAM” indicators to tell you which debug connector is which. Check out how nice and small the unit is. This is another improvement over the JTAGICE2, and a real benefit on a crowded desk or lab bench.

Here is the cables that come in the 85-dollar unit. You also get the USB cable. Note the one cable comes with that cool breakout board.

The breakout board has a silkscreen on both sides to help you figure out what it plugs into.

Using Arduino PWM for constant-current drive

The always excellent Circuit Cellar Magazine has a nice article by Ed Nisley. Arduino PWM vs MOSFET Transconductance describes his characterization of Arduino PWM outputs for the constant-current drive of MOSFETs. His application is LED drive, but you could use the knowledge anywhere, including a programmable current sink. Now Circuit Cellar is a paid-subscription magazine, so I can’t link to free article, but maybe their lawyers will let me take a picture of a picture in the print magazine, to which I am a long-time subscriber.

This photo of the board Ed Nisley used to develop his constant-current source tells you it is not some Spice simulation or a theoretical track. This is a sure tip-off that Ed knows what he is writing about.

This scope shot also reassures you that Ed is not venturing forth some opinion on how the hardware and firmware works, it is proof positive he built this stuff and that it really works. I scratched off the readouts to make sure this is fair use and not a violation of Circuit Cellar’s copyrights.

Analog Guru Paul Grohe taught me that you should always look for pictures of real hardware in articles, and that if the curves are ”too pretty” they are probably marketing BS instead of real data. That is the great thing about this article; it’s got both pictures and data that tell you that you can trust the content.

There is another interesting article in the March 2014 Circuit Cellar issue. It’s about an outfit called ImageCraft. They make a C compiler with an IDE (integrated development environment) for Atmel AVR and ARM Cortex-based MCUs. Now I am a fan of Atmel’s free Studio 6 IDE, but feel free to use whatever IDE you prefer to write the code for your projects.

Now I can’t show you these articles on-line, since Circuit Cellar is a subscription print magazine. You have to give them 50 bucks a year to get it. You can get it as a digital pdf if you want to save trees. Its $85 a year for the both print and digital versions. There are large discounts for two- or three-year subscriptions. Best of all, you can give them something like $225 and get every single issue in history on a thumb drive. Then with your combo subscription you can add your monthly pdf to the archive thumb drive, and still have the print edition to impress your friends and boss.

Atmel’s ToT hits the road for EELive!

Atmel’s Mobile Training Center is heading to Las Vegas Nevada on March 26th and EE Live! in San Jose in early April.

We’ll be at the McEnery Convention Center on 150 W San Carlos on Tuesday, April 1 – Thursday, April 3, showcasing a wide variety of tech across a number of spaces 
including touch, security, microcontrollers (MCUs), wireless, lighting and automotive.

More specifically, you can check out:

• Agent smartwatch (Secret Labs) powered by Atmel’s ARM-based SAM4S and tinyAVR MCU
• Philips Hue Bulbs with Atmel‘s ZigBee and Lightweight Mesh Stack
• Turtle Beach i60 Wireless Gaming Headset with Atmel Wi-Fi
• Direct
Roku3 remote with Atmel’s Wi-Fi Direct
• Venstar Color Touch Thermostat with Atmel’s ARM9-based MCU
• Makerbot 3D printer with Atmel AVR microcontrollers
• ASUS T100 Transformer with Atmel’s MaxTouch T Series Cap Touch controller and XSense Metal mesh touch sensors
• Atmel Studio IDE

Atmel, along with Xively, will also be co-hosting an Internet of Things (IoT) Engineering Summit at EE Live! on Tuesday, April 1, 2014 @ 11:00 – 11:45 am. Participants are slated discuss the following IoT-related topics:

• Embedded processing and security
• Connectivity and interface
• Software tools and development

You can register for Atmel’s ToT Las Vegas stop here and EE Live! here.

Interested in learning more about Atmel and the IoT? You can check out our article archive on the subject here as well as Atmel’s recent SoMa panel discussion on the IoT here.

Agricultural monitoring with Atmel AVR

Calibit is a digital caliper equipped with an AVR-powered data logger that allows the device to efficiently monitor hectares of orchards.

The datalogger – based on an 8-bit Atmel microcontroller (MCU) – features 128Kb EEPROM memory, LCD display, USB/UART slots, watch/calendar, as well as a rechargeable lithium battery with integrated safety system and temperature control.

“[This] new technology promotes the monitoring of fruit growth as it simplifies data collection – 15-20 minutes is all it takes to gather enough data to monitor each hectare,” a FreshPlaza writer explained in a recent article.

“[Plus, users can] create multiple measuring sessions to group data and improve management, [with] the USB cable and software enabling data downloads in CSV format.”

Although Calibit was originally designed to monitor fruit growth, the platform is capable of supporting a wide-range of applications including:

• Cooperatives and collection warehouses to sample fruit before processing
• Plant nurseries to verify the diameter of striplings, branches and trunks
• Mechanical and carpentry workshops
• Scientific laboratories

Interested in learning more? You can check out Calibit’s official product site here. Readers may also want to browse through some of our previous stories on technology and farming including “The Internet of Things, Stalk by Stalk,” “Smart Urban Aquaponics in West Oakland“, “DIY Farming with Atmel and Arduino” and “Open Source Aquaponics with APDuino.”

SAMA5 and SAM9: Atmel’s big iron microprocessors

Atmel is rightly famous for its AVR line of 8-bit Flash microcontrollers. But we also have “big iron” chips like the SAMA5 and SAM9 ARM-core microprocessors. A microcontroller has its own internal Flash memory. A microprocessor uses external memory, as much or as little as your application might need.

Hardware engineers have two big worries with any “big iron” microprocessor. First, they are in big packages, hundreds of pins in a ball-grid array. That can be hard to prototype with, since it needs a fine-line PCB that costs a lot to spin. The other big concern is laying out the DDR memory interface. These are wickedly fast and require best layout practices and some register tweaking to get them up to full speed.

The SAMA5D3 Xplained kit has connectors for Arduino Shields and dual Ethernet ports.

Thankfully, Atmel has solved both problems with a series of evaluation systems. For the SAMA5, you can start with a 79-dollar SAMA5D3 Xplained Kit. It has solved your DDR memory problem since it’s got 256MB on-board. One of the coolest things is that it has connectors where you can plug in any Arduino Shield. Now you can’t use the Arduino libraries, those are based on Atmel’s 8-bit AVR, but it’s not hard to re-write the open source code libraries into something that will run on ARM, if someone hasn’t done it already. The eval board has Atmel’s SAMA5D36 Cortex-A5 Microprocessor, 256Mbytes of NAND Flash, LCD connectors, dual Ethernet (GMAC + EMAC) with PHY and connectors, three USB connectors (2 Host + 1 Device), one SD/eMMC and one MicroSD slots, expansions headers, and power measurement straps.

Atmel makes eval kits for the SAM9N12 (left) and SAM5D3x ARM-based microprocessors.

For those that are doing higher-level applications, the fact that you can run Linux brings all the advantages of open-source development to the SAMA5 and SAM9 microprocessors. And best yet, you get a powerful CPU that uses very little power thanks to Atmel’s architecture. The SAMA5 uses 150mW when running at full speed. It has a DDR controller that give you 1328MB/s of bandwidth. It comes with for gigabit Ethernet, 3 USB ports, dual CAN, UARTs, SPI, and an LCD controller with a graphics accelerator. There is a camera interface, a 12-bit analog to digital converter (ADC) and 32-bit timers.

A SAMA5 chip can run Linux and even has the power to run Android in a “headless” application, that is, where there is not a high-resolution display to eat up your CPU cycles. With an ARM core it’s ideal if you want to do “bare metal” development, where you are writing native ARM code.

The SAM9N12 architecture gives you low power and a great peripheral set.

Looking at the SAM9, the SAM9CN runs at 400MHz. They have security built in with a cryptographic engine and a secure boot. There is an LCD controller with touchscreen interface, USB, MLC NAND memory support, along with multiple UARTs and I²C. It sips 103mW at 400MHz.

You can get separate LCD panels made to work with the SAMA5 Xplained kit. But if you want to get a SAMA5 kit with the LCD already included, look at the 595-dollar SAMA5D31, SAMA5D33, SAMA5D34 and SAMA5D36 kits. There is also the 445-dollar SAMA5D35 kit, which is cheaper since it does not have an LCD system. These kits cost more but they come ready to go. These are a small working computer that you can immediately start programming in high-level languages or Linux scripts. The kits come with installed applications for its Qt-based GUI.

The SAM5A5Dx-EK demo kit comes with Linux and some demo applications pre-installed.

And if you dread laying out a PCB with a working DDR memory interface, but don’t need the whole $595 kit, you can get help there as well. You will notice that the microprocessor and memory are on a little mezzanine PCB in the SAMA5D3 demo kits. This PCB will be available from Embest and other partners. The SAM9 is also available as a tiny SBC (single-board computer).

The SAMA5D3-EK series are designed with a mezzanine card holding the CPU and DDR memory. You can use this card in your high-volume designs.

So now you can develop your custom hardware starting with the SAMA5D3 kit, and then make your own custom hardware that still uses the same exact CPU+memory mezzanine card. While you are perfecting and troubleshooting that hardware, your software team can be working on the Atmel eval kit. This paralleled development will substantially speed up your time to market. And best yet, you won’t be bogged down trying to troubleshoot the DDR memory interface, since it is already working on the mezzanine card.

So don’t just think of 8-bit AVRs when you consider Atmel. We make some really high-power MPU products for everything from IoT (Internet of Things) servers to routers and industrial automation. With Atmel’s kits and our extensive partner network, we can get you up and running in no time, for very little cost, and you can have confidence you designs will work on that final hardware spin.

Passing CE immunity testing

When I was working on semiconductor machinery, we used TUV to get CE certification so we could sell the machines in Europe. We got through emissions alright, it’s similar to the FCC testing we already did, but immunity testing was brutal. When we broadcast RF at a machine, the wafer elevators went nuts and started breaking wafers. We had managed to convince the TUV guy that the speckles and snow on the monitor were not technically a failure, since you could still read it. But robots going open-loop? No, nobody could talk that past TUV. Turns out the cabling was the culprit. There was shielded twisted pair to the Banner sensors that located the elevator stops. In fact, I think they even used braid+foil shielded wire. But the semiconductor machinery company connected the cables with those red-brick AMP connectors, the MR series.

MR These MR (miniature rectangular) connectors work great for appliance wiring, but they provide no continuous shielded path for radio frequency interference (RFI).

Now designing cabling is often thought of as a mechanical engineering function. But mechanical engineers often don’t understand the principles of RF shielding. Get this— they cut the cable shielding about 2 inches back, connected the power, ground, and signal to pins, and yeah, they connected the braid to a pin, and sent it into the connector, to mate with another cable that had 2 inches pulled back. The cables were all dressed beautifully and shrink tubing everywhere. But like my buddy says—“4 inches of untwisted unshielded wire is a nice antenna.”

D-sub The D-sub connector was developed for military applications and then picked up by PC makers for serial, parallel and video ports. One reason is its good RF performance. Make sure your cable braid contacts the metal shell.

I switched them to D-subs using 9 pins with a metal shell, and we finally passed. So remember, RF energy is like light—it can leak into the smallest spaces and screw things up. Make sure the EE department revises the detailed design of the cable, or your machine might get held up in certification too.