Engineering by Technology - RF/RFID Design

Project

Set Top Box

Application

In-Home Patient Monitor

Customer Need

More people are addressing health care at home. However, these same people are not trained care givers and require automated monitoring, reminders for medications and other tasks, and alert systems to notify for assistance. Collected data can be downloaded to doctors for analysis, adjustments to medication and other diagnosis. Some monitoring equipment is worn by the patient with wireless reporting ability. The use of a set top box allows on TV screen instructions, and interfaces via broadband modem and the Internet to the professional care giver.

AVID's Solution

A high end Power PC-based design was implemented, capable of running a high level Linux operation system. This allowed the use of library functions for communication, encryption, graphics, sound, and others. ISM-band RF interfaces were designed to collect data from remote, patient-worn monitor devices and panic keypad remotes. Ethernet was included as the link to the remote care giver locations; as well an option was included to add CDMA. Audio alarms alerted the patient if action was required. A modulation circuit allowed for custom screens to be displayed on specific TV channels. Multiple DSPs were implemented off a PCI bus from the PPC to allow for real time video processing.

Value Added or Technologies Applied

Hardware Architecture
Hardware Design and Advanced PCB Layout; PPC High-Speed DRAM, Daisy-Chained DSP Array, External Interfaces (RF and Ethernet), NTSB Video and Audio, USB 2.0
Prototype and Validation
Software Integration Support

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Project

Control Electronics

Application

Down-Hole Drilling System

Customer Need

Our customer acquired Intellectual Property relating to techniques to detect the earth content, looking for oil and gas pockets. The drill head uses this information to determine the direction of the drill head, and other aspects important for well development. This application is brutal to the electronics in terms of heat and vibration. Reliable packaging was critical to the project. Additionally, RF technology is included in the techniques and required accurate low frequency transmitters and receivers for the sent and reflected waveforms. A communications interface with surface instruments is part of the down-hole system.

AVID's Solution

The design included custom RF design along with microprocessor control and an FPGA implementation. Power conversion stability and efficiency were required for proper operation. Special consideration was made for the PCB implementation to help insure parts would stay on the boards. Correction factors and other techniques were used to insure the accuracy of the RF signals. Multiple boards were required as the physical constraints dictated long and skinny outlines. This required careful system partitioning. The boards were encased in silicone rubber for protection and resistance from the elements.

Value Added or Technologies Applied

System Architecture / Component Selection / Partitioning
Hardware Design and Implementation, FPGA Code
Prototype and Validation
Production of Multiple Systems for Testing and Field Trials
Manufacturing Engineering Support; Production Test Procedure

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Project

HART-Enabled Interfaces

Application

Industrial Communication Devices

Customer Need

The HART industrial communication protocol is the most prevalent digital communications interface used today for smart transmitters and actuator devices. This digital communications allows plant operators to retrieve additional information from the field devices for maintenance, asset management, diagnostics, and normal process monitoring. Plant personnel have the need for portable devices that communicate via HART. Additionally, many older plants cannot take advantage of smart transmitters and field actuators as the control systems are not HART-enabled. These interface devices allow plant personnel access to this enhanced data.

AVID's Solution

AVID has helped our client become the standard HART interface against which all other HART devices are measured. Using a highly customized discrete solution for the HART front end with an advanced ASIC for the protocol has allowed our customer to deliver HART interfaces with serial, USB, and Bluetooth connection to laptops and PDAs. Participating in the HART standard's committees has allowed us to not only develop products, but also contribute to the standard and compliance requirements. More recent development has been in the Wireless HART area where we have participated in the draft standard. We have completed a Wireless HART adaptor design which allows existing HART devices to communicate over the new wireless HART network. Innovations in low power design and power management have resulted in a loop powered device with 1V insertion loss. Additionally, the product has been designed for compliance with hazardous location requirements. The housing provides for mounting to the spare port of a smart device.

Value Added or Technologies Applied

Participation in the Wireless HART Standards Committee and Working Groups
Product Specification
Product Packaging and Device Interface. Material Selections Compliant with Standards
Hardware, Firmware, and Mechanical Design and Documentation. Advanced Antenna Design
Prototype and Validation
PC Application and Device Drivers
Engineering Build for Agency Test and Field Trials
FM, ATEX Submittal and Support
Production Test System Development
Manufacturing Support

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Project

RF Electronics

Application

Audience Response System

Customer Need

Live audience participation in presentations provides a valuable enhancement to the presentation experience. However, large audiences require the ability to accurately collect large amounts of data real-time and the response devices must not interfere with each other. Battery life and cost are two critical design parameters beyond the primary ability to send reliable RF.

AVID's Solution

Our customer had the basic design architecture, but the implementation delivered unacceptable performance. AVID performed a complete review of the design, looking for ways to achieve the required performance while also evaluating the design with regard to cost; either by improvements to the BOM or production processes. AVID also managed initial engineering builds which provided our customer with production-level devices for demonstrations and field trials.

Value Added or Technologies Applied

Hardware and Firmware Architecture Design Review
Circuit Re-Design and RF Performance Testing
PCB Layout, Design for Manufacturability
Prototype and Validation
Patent Application Support
Volume Engineering Builds
Manufacturing Engineering Support

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Project

Passive Keyless Entry System

Application

Vehicle Electronics

Customer Need

A Tier1 automotive company desired a fully functional, production-ready design of a passive keyless entry and ignition system to offer to major automotive OEMs. The system uses low frequency immobilizer technology leveraging RFID techniques. System components include base station, key fob, and highly directional antennas. A system prototype integrated into an actual vehicle for presentation purposes is included in the development program.

AVID's Solution

Using technology and components which are targeted for RKE and RFID, AVID designed the base station and key fob boards. HF was used for traditional push button operation, whereas LF was used to achieve the passive hands-free mode. Multiple antennas are required to accurately detect the position of the fob; inside or outside the vehicle. This allows starting when inside the passenger compartment, but inhibited when outside. Additionally, a locked door will remain locked when the fob is inside, but unlocks when in close proximity outside. Custom omni-directional antennas to facilitate LF and HF wavelengths were designed to fit in side view mirrors, door handles, and in the passenger compartment. A custom electro-mechanical latch was designed to address combo electro-mechanical and straight mechanical opening and locking. Rolling code algorithms were implemented for security. The fob required special attention to power management to achieve long battery life. Critical factors considered for the design include automotive environmental and EMC requirements, cost, reliability, safety, and adaptability to different vehicles.

Value Added or Technologies Applied

Product Specification
System Architecture and Design (Hardware, Firmware, Mechanical, RF)
Prototype and Validation
Multiple Demonstration System Integrations (Vehicle Cut-Away, Full Vehicle, Motorcycle, Bench Top Demo System)
Project Management of Several Third Party Contributors of System Components
Manufacturing Engineering Support, Production Test Procedure
Customer Support for OEM Presentations and SAE Show Support for Demo Platforms and Booth Duty

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Project

Keyless Ignition Electronics

Application

Vehicle Key Fob

Customer Need

A mechanically-oriented customer needs electronic design assistance for a keyless fob ignition system. The system incorporates off-the-shelf immobilizer technology but requires electronics for position detection of the fob for the different states of ignition power normally addressed by a key switch. In this case the fob is inserted into a movable trolley to achieve the equivalent of accessory, on, start, and off. A push to start feature is required along with dimmable panel lighting, and interface to other vehicle electronics. Compliance with the automotive MISRA documentation standard was required.

AVID's Solution

A low cost microcontroller was implemented to perform sensing of limit switches which were triggered by the trolley position. Dedicated outputs were controlled based on a closely controlled state machine based on normal operation requirements but constrained by safety and fail safe considerations. PWM was used for backlight dimming of the panel lighting provided by LEDs. Multiple LEDs and light pipes were used for a consistent brightness. All software documentation was created to comply with the MISRA spec. Special care was paid to the board design to meet stringent automotive requirements for power and EMC.

Value Added or Technologies Applied

Hardware and Firmware Architecture
Hardware and Firmware Design and Documentation Compliant with Automotive Standard
Prototype and Validation
Engineering Build for Customer Testing and Field Tests
Qualification Test Support
Manufacturing Support

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Project

Wireless Sensor Acquisition System

Application

Engine Monitoring

Customer Need

Our customer received a government contract to develop a wireless sensor system to be used to monitor and record various engine parameters such as battery voltage, engine oil level and viscosity, antifreeze temperature, vibration monitoring, and so on. To eliminate wiring, the sensors were to be battery powered and include a low cost wireless interface. The base station is powered from the vehicle battery and includes sufficient storage of sensor data history, its own I/O, and a Bluetooth interface which provides for downloading vehicle data wirelessly at the maintenance facility.

AVID's Solution

AVID was asked to design a prototype model of the system first. Once proven and approved by the government, a Phase 2 would follow for actual packaging of the sensors. The system was designed around a custom 915MHz RF link. Each sensor was addressable and reported data when requested by the base. The sensor design included analog inputs capable of voltage or current inputs, software programmable gain stage, and 12 bit A/D. A factory calibration process allowed the use of embedded reference and other non-precision components. The base station included similar inputs as well as the memory for data storage. An off-the-shelf Bluetooth module was selected for the model to shorten development time and cost. Several boards were made which were actually put into vehicle to complete the proof of concept.

Value Added or Technologies Applied

System Architecture, Sensor Electronics and Base Station Hardware and Firmware Architecture
Hardware Design of the Base Station and Sensor Board
Firmware Design of the Sensor Board, Firmware Driver Design and Test Code for the Base Station
PCB Layout of Both Boards
Prototype and Validation
Engineering Builds for Proof of Concept Systems
EMC Test Support

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