Embedded Systems Academy

The CAN in Automation documents known as CiA447 describe how CANopen is used in automotive “add-on electronics” applications. These are electronics not added by the car manufacturer, but at a later point. Most common usage is for electronics used in taxis, emergency response vehicles and police cars.

Recently CiA447’s functionality was enhanced and especially the new power-down and wake-up procedures required a version step upwards, as they are not backward compatible.

Today, Daimler is the only manufacturer already offering cars with CiA447 interface. However, several other car manufacturers have already shown prototypes.

One of the biggest benefits of CiA447 is, that it offers add-on electronics access to some of the cars displays and buttons. In modern cars, there is typically no physical room to add electronics near the dashboard, as all space is used up. CiA447 allows “sharing” some of the cars displays and buttons, so that the electronic components themselves do not need to be mounted near the dashboard.

We at ESAcademy have now updated all our CANopen products for CiA447 to implement the latest V2.0 enhancements and changes. This includes our Micro CANopen source code solutions, our CANopen Magic line of analyzers and our CiA447 gateway simulator. Contact us, if you need to bring CiA447 to your electronics.

For many years the maximum bit rate of CAN (Controller Area Network) has been 1Mbps. Not only was it a maximum for the bit rate, it also resulted in a “touchy” physical layout: cable length restrictions were as low as 30m.

The limits of speed vs. cable length comes from the requirement, that in CAN a bit needs to be stable on the entire bus, before the next bit may start. Some bits can be over-written, a feature which is used for arbitration, acknowledgments and error handling.

Bosch, the inventor of CAN, now introduced a white paper “CAN with Flexible Data-Rate” showing how a higher data rate can be achieved. The main suggested feature here is to allow switching between a low (backward compatible) bit rate and a much higher bit rate within a single message.

In short, a single CAN message consist of control data at the beginning and the end of a message with the data field “in the middle”. The core idea is to use the lower bit rate for the control data and the higher bit rate for the data field only. In addition the maximum data field size is increased from previously 8 bytes to now 64 bytes.

If the higher bit rate is 8 times higher than that of the base rate it would be possible to achieve an 8 times higher data-throughput WITHOUT changing the real-time behavior.

For more info, see the white paper at:
www.semiconductors.bosch.de/media/pdf/canliteratur/can_fd.pdf

The new LPC4000 family of microcontrollers from NXP Semiconductors combines two powerful ARM Cortex cores in one microcontroller. The integrated Cortex-M4 and Cortex-M0 can run asymmetrically at up to 150MHz and have access to internal memory of up to 1MB Flash and 264k of RAM.
A multilayer bus matrix with 4 separate RAM blocks ensures that both microcontrollers have independent, fast access to “their” memory, minimizing wait-states.
Next to the “usual” LPCxxx peripherals the new devices also feature high-speed USB and an AES decryption engine for security.
There are several applications that benefit from a dual core solution. If a lot of communication is required, like handling complex communication protocols with specific timing requirements, a dual-core solutions allows using one core as a communication co-processor, clearly separating communication and process handling.
For more information, see NXP’s web pages.

I was visiting Embedded World this week and in regards to microcontrollers the trend towards 32bit continues. When it comes to marketing presence at a trade show, obviously less than 32bit where not “it” this year. Not only chip manufacturers, but also most of the development tools primarily focused on 32bit solutions. And the next impression one gets walking the aisles: ARM processors are the first choice in this arena, with a focus on the Cortex-M generation. At this year’s Embedded World, no other microcontroller architecture had a marketing presence anywhere near that of ARM. Read more…

Whenever a new microcontroller generation comes out, developers and engineers look out for evaluation boards. In order to be able to test the microcontroller, it needs to be mounted on a PCB that has the required glue logic, power circuitry and connectors. For generations, these test boards were mostly “bare-naked” – without housing and only featuring components needed to test the microcontroller in certain types of applications. Over the last years more “attractive” variations of such boards have come to market, for example some looking like a custom USB stick.

Last year, Raisonance released products following a slightly different concept they named Primers, and the Primer2 won an EETimes product of the year 2009 award. These boards feature a complete housing, making them more attractive for various prototype developments. Through staging several design contests, many applications have been implemented and are now shared on the product’s web page. Applications include an alcohol meter, a CAN monitor, a GPS displaying OpenStreetMap data, various games and many more. Read more…

A few years back, Al Gore was speaking at the Embedded Systems Conference. His key note also included the call upon us engineers to do more to ensure that embedded systems use less power. With the billions of microcontrollers out there, all the milliwatts that we can potentially save in each one do add-up. Although many microcontroller manufacturers already offer multiple power saving options on their devices, it is not always easy to get exact values. Any change in clock rate, also on any of the peripherals, immediately has an affect on the overall power consumption. But how much do we really save by reducing the clock to a communication peripheral?

This year, one of the Embedded Awards given out every year at the Embedded World is for a product that helps engineers with measuring the power consumption of their system dynamically. The PowerScale by Hitex not only allows measuring a system’s current power consumption – it makes that information available via an API so that debuggers can include the information into the trace recording or other displays.

This allows engineers to easily determine which code areas have an impact on the overall power consumption. The power-saving effect of reducing clock rates or disabling unused peripherals becomes immediately visibile.

Various adapter probes including a USB and Power-over-Ethernet Probe are available to allow for an easy connection of the up to four channels to the target hardware.