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.

Robot Nav with Acoustic Delay Triangulation

Building a robot is a rite of passage for electronics engineers. And thus this magazine has published dozens of robotics-related articles over the years.

In the March issue, we present a particularly informative article on the topic of robot navigation in particular. Larry Foltzer tackles the topic of robot positioning with acoustic delay triangulation. It’s more of a theoretical piece than a project article. But we’re confident you’ll find it intriguing and useful.

Here’s an excerpt from Foltzer’s article:

“I decided to explore what it takes, algorithmically speaking, to make a robot that is capable of discovering its position on a playing field and figuring out how to maneuver to another position within the defined field of play. Later on I will build a minimalist-like platform to test algorithms performance.

In the interest of hardware simplicity, my goal is to use as few sensors as possible. I will use ultrasonic sensors to determine range to ultrasonic beacons located at the corners of the playing field and wheel-rotation sensors to measure distance traversed, if wheel-rotation rate times time proves to be unreliable.

From a software point of view, the machine must be able to determine robot position on a defined playing field, determine robot position relative to the target’s position, determine robot orientation or heading, calculate robot course change to approach target position, and periodically update current position and distance to the target. Because of my familiarity with Microchip Technology’s 8-bit microcontrollers and instruction sets, the PIC16F627A is my choice for the microcontrollers (mostly because I have them in my inventory).

To this date, the four goals listed—in terms of algorithm development and code—are complete and are the main subjects of this article. Going forward, focus must now shift to the hardware side, including software integration to test beyond pure simulation.

A brief survey of ultrasonic ranging sensors indicates that most commercially available units have a range capability of 20’ or less. This is for a sensor type that detects the echo of its own emission. However, in this case, the robot’s sensor will not have to detect its own echoes, but will instead receive the response to its query from an addressable beacon that acts like an active mirror. For navigation purposes, these mirrors are located at three of the four corners of the playing field. By using active mirrors or beacons, received signal strength will be significantly greater than in the usual echo ranging situation. Further, the use of the active mirror approach to ranging should enable expansion of the effective width of the sensor’s beam to increase the sensor’s effective field of view, reducing cost and complexity.

Taking the former into account, I decided the size of the playing field will be 16’ on a side and subdivided into 3” squares forming an (S × S) = (64 × 64) = (26, 26) unit grid. I selected this size to simplify the binary arithmetic used in the calculations. For the purpose of illustration here, the target is considered to be at the center of the playing field, but it could very well be anywhere within the defined boundaries of the playing field.

Figure 1: Squarae playing field (Source: Larry Foltzer CC260)

Referring to Figure 1, the corners of the square playing field are labeled in clockwise order from A to D. Ultrasonic sonar transceiver beacons/active mirrors are placed at three of the corners of the playing field, at the corners marked A, B, and D.”

The issue in which this article appears will available here in the coming days.