Tech Highlights from Design West: RL78, AndroPod, Stellaris, mbed, & more

The Embedded Systems Conference has always been a top venue for studying, discussing, and handling the embedded industry’s newest leading-edge technologies. This year in San Jose, CA, I walked the floor looking for the tech Circuit Cellar and Elektor members would love to get their hands on and implement in novel projects. Here I review some of the hundreds of interesting products and systems at Design West 2012.


Renesas launched the RL78 Design Challenge at Design West. The following novel RL78 applications were particularly intriguing.

  • An RL78 L12 MCU powered by a lemon:

    A lemon powers the RL78 (Photo: Circuit Cellar)

  • An RL78 kit used for motor control:

    The RL78 used for motor control (Photo: Circuit Cellar)

  • An RL78 demo for home control applications:

    The RL78 used for home control (Photo: Circuit Cellar)


Circuit Cellar members have used TI products in countless applications. Below are two interesting TI Cortex-based designs

A Cortex-M3 digital guitar (you can see the Android connection):

TI's digital guitar (Photo: Circuit Cellar)

Stellaris fans will be happy to see the Stellaris ARM Cortex -M4F in a small wireless application:

The Stellaris goes wireless (Photo: Circuit Cellar)

NXP mbed

Due to the success of the recent NXP mbed Design Challenge, I stopped at the mbed station to see what exciting technologies our NXP friends were exhibiting. They didn’t disappoint. Check out the mbed-based slingshot developed for playing Angry Birds!

mbed-Based sligshot for going after "Angry Birds" (Photo: Circuit Cellar)

Below is a video of the project on the mbedmicro YouTube page:


I was pleased to see the Elektor AndroPod hard at work at the FTDI booth. The design enables users to easily control a robotic arm with Android smartphones and tablets.

FTDI demonstrates robot control with Android (Photo: Circuit Cellar)

As you can imagine, the possible applications are endless.

The AndroPod at work! (Photo: Circuit Cellar)

Organic Magnetism & Electronic Applications

Innovative researchers in Japan are looking closely at organic magnetism and how it can be applied to electronic systems. Could carbon-based organic materials eventually replace inorganic materials (i.e., silicon and other metals) in future electronic applications?

In a post titled “Organic Electronics: The Secret of Organic Magnets Unlocked” at, Tessel Renzenbrink explains the results of exciting research by Japanese scientists studying the origin of magnetism in organic compounds. Tessel writes:

Organic light- emitting diodes (OLEDs) are already commercially in use in displays of mobile devices and significant progress has been made in applying organic photovoltaic cells to a light-weight flexible fabric to generate low-cost solar energy. But an entirely new range of applications is possible such as disposable biodegradable RFID tags and biomedical implants.

One of the limiting factors of organic materials is that they rarely exhibit magnetic properties because their atomic structure is fundamentally different from metals. But for electronic applications such as data storage and electric motors magnetism is essential.

Now a team of scientists from the RIKEN research center has established an exact theoretical model which could aid materials scientists to develop organic magnetic materials.

You can read the entire post at is part of the Elektor group. 



Elektor RF & Microwave App for Android

Elektor has an iPhone/iPad app for several months. And now Android users can have an Elektor app of their own. The Elektor RF & Microwave Toolbox app is perfect for engineers and RF technicians who need easy, reliable access to essential equations, converters, calculators, and tools.

A screenshot of the Elektor RF & Microwave app for Android

The app includes the following handy tools:

1.Noise floor (Kelvin,dBm)
2.Amplifier cascade (NF, Gain, P1db, OIP2, OIP3)
3.Radar equation (2-way path loss)
4.Radio equation (1-way path loss)
5.Power and voltage converter (W,dBm,V,dBµV)
6.Field intensity and power density converter (W/m2, V/m, A/m, Tesla, Gauss,dBm, W)
7.Mismatch error limits (VSWR, Return loss)
8.Reflectometer (VSWR, Return loss)
9.Mitered Bend
10.Divider and Couplers (Wilkinson, Rat race, Branchline , microstrip and lumped)
11.Balanced and und balanced PI and T attenuator
12.Skin depth (DC and AC resistance)
13.PCB Trace calculator (impedance/dimensions)
14.Image rejection (amplitude and phase imbalance)
15.Mixer harmonics (up and down conversion)
16.Helical antenna
17.Peak to RMS (peak, RMS, average, CF)
18.Air Core Inductor Inductance
19.Parallel plate Capacitor
20.PI and T attenuator
21.Ohm’s Law
22.Parallel LCR impedance/resonance
23.Series LCR impedance/resonance
24.Inductor impedance
25.Capacitance impedance
26.Antenna temperature (Kelvin)
27.Radar Cross Section (RCS) calculator (Sphere,Cylinder, flat plate, corners, dBsm)
28.Noise Figure Y-Factor Method
29.EMC (EIRP, ERP, dBµV/m)
30.Noise figure converter (dB, linear, Kelvin)
31.Frequency Band Designations
32.Resistor color code (reverse lookup, 3 to 6 band)
33.Filter Design (Butterworth, Chebyshev, prototype):
34.µ-Filter Design (microstrip, stripline)
35.PCB Trace Width and Clearance Calculator

Visit the Android Market for more information about the Elektor app.

Circuit Cellar does not yet have an app for Android. The Circuit Cellar iPhone/iPad app is available on iTunes.

Screenshots of the Circuit Cellar app

Elektor International Media is the parent company of Circuit Cellar.

Zero-Power Sensor (ZPS) Network

Recently, we featured two notable projects featuring Echelon’s Pyxos Pyxos technology: one about solid-state lighting solutions and one about a radiant floor heating zone controller. Here we present another innovative project: a zero-power sensor (ZPS) network on polymer.

The Zero Power Switch (Source: Wolfgang Richter, Faranak M.Zadeh)

The ZPS system—which was developed by Wolfgang Richter and Faranak M. Zadeh of Ident Technology AG— doesn’t require battery or RF energy for operation. The sensors, developed on polymer foils, are fed by an electrical alternating field with a 200-kHz frequency. A Pyxos network enables you to transmit of wireless sensor data to various devices.

In their documentation, Wolfgang Richter and Faranak M. Zadeh write:

“The developed wireless Zero power sensors (ZPS) do not need power, battery or radio frequency energy (RF) in order to operate. The system is realized on polymer foils in a printing process and/or additional silicon and is very eco-friendly in production and use. The sensors are fed by an electrical alternating field with the frequency of 200 KHz and up to 5m distance. The ZPS sensors can be mounted anywhere that they are needed, e.g. on the body, in a room, a machine or a car. One ZPS server can work for a number of ZPS-sensor clients and can be connected to any net to communicate with network intelligence and other servers. By modulating the electric field the ZPS-sensors can transmit a type of “sensor=o.k. signal” command. Also ZPS sensors can be carried by humans (or animals) for the vital signs monitoring. So they are ideal for wireless monitoring systems (e.g. “aging at home”). The ZPS system is wireless, powerless and cordless system and works simultaneously, so it is a self organized system …

The wireless Skinplex zero power sensor network is a very simply structured but surely functioning multiple sensor system that combines classical physics as taught by Kirchhoff with the latest advances in (smart) sensor technology. It works with a virtually unlimited number of sensor nodes in inertial space, without a protocol, and without batteries, cables and connectors. A chip not bigger than a particle of dust will be fabricated this year with the assistance of Cottbus University and Prof. Wegner. The system is ideal to communicate via PYXOS/Echelon to other instances and servers.

Pyxos networks helps to bring wireless ZPS sensor data over distances to external instances, nets and servers. With the advanced ECHELON technology even AC Power Line (PL) can be used.

As most of a ZPS server is realized in software it can be easily programmed into a Pyxos networks device, a very cost saving effect! Applications start from machine controls, smart office solutions, smart home up to Homes of elderly and medical facilities as everywhere else where Power line (PL) exists.”

Inside the ZPS project (Source: Wolfgang Richter, Faranak M.Zadeh)

For more information about Pyxos technology, visit

This project, as well as others, was promoted by Circuit Cellar based on a 2007 agreement with Echelon.

GPS-Based Vehicle Timing & Tracking Project

The KartTracker’s Renesas kit (Source: Steve Lubbers CC259)

You can design and construct your own vehicle timing system at your workbench. Steve Lubbers did just that, and he describes his project in Circuit Cellar 259 (February 2012). He calls his design the “Kart Tracker,” which he built around a Renesas Electronics Corp. RX62N RDK. In fact, Steve writes that the kit has most of what’s need to bring such a design to fruition:

Most of the pieces of my KartTracker are already built into the Renesas Electronics RX62N development board (see Figure 1). The liquid crystal display (LCD) on the development board operates as the user interface and shows the driver what is happening as he races. The integrated accelerometer can be used to record the G forces experienced while racing. A serial port provides connections to a GPS receiver and a wireless transmitter. Removable flash memory stores all the race data so you can brag to your friends. You now have all of the pieces of my KartTracker.

The following block diagram depicts the relationship between the CPU, base station, flash drive, and other key components:

KartTracker Diagram (Source: Steve Lubbers CC259)

The software for the system is fairly straightforward. Steve writes:

The KartTracker software was built around the UART software sample provided with the RX62N development kit. To provide file system support, the Renesas microSD/Tiny FAT software was added. Finally, my custom GPS KartTracker software was added to the Renesas samples. My software consists of GPS, navigation, waypoints, and display modules. Support software was added to interface to the UART serial port, the file system, and the user display and control on the RX62N circuit board.

Pseudocode for the main processing loop (Source: Steve Lubbers CC259)

Read Steve’s article in the February issue for more details.

If you want to build a similar system, you should get familiar with the Renesas RX62N RDK. In the following video, Dave Jones of EEVBlog provides a quick and useful introduction to the RX62N RDK and its specs (Source: Renesas).

Good luck with this project. Be sure to keep Circuit Cellar posted on your progress!

Click here to purchase Circuit Cellar 259.