Engineering by Technology - Embedded Systems

Project

Control Electronics

Application

Diesel-Fired Military Tent Heater

Customer Need

MIL-compliant electronic control of all aspects of a military tent heater including start/stop sequence, closed-loop temperature control, fuel/air mixture, fan motor control, power management and battery charging with system power provided by a Thermo-Electric Generator (TEG). Additional requirements included a remote temperature sensor and user-set point input, with CO monitor.

AVID's Solution

Our engineering services extended beyond board and firmware design to satisfy all of the needs listed above as it included system level operational aspects, use cases, diagnostics, addressing unit to unit variations of the burners and TEGs, and corner case conditions. AVID was responsible for the complete board level design, embedded and system firmware, and system verification to Military requirements. AVID assisted in electronics packaging, cable harness design, and release to manufacturing. We also created a real-time executable for the PC that allows test engineers to monitor and modify run-time parameters during system test without the need to reprogram the system.

Value Added or Technologies Applied

• System Operation and Use Case
• Control Architecture
• Hardware and Firmware Design and Implementation
• Prototyping and Validation
• PC Application Development
• System Qualification Support
• Manufacturing Engineering

Project

Custom Trackball Interface

Application

Control System

Customer Need

An industrial trackball interface that communicates over a proprietary serial channel to a custom MIL-SPEC VME CPU. The trackball electronics transmit actual X-Y position over an SDLC communication channel using a proprietary protocol. All inputs and outputs are isolated.

AVID's Solution

The SDLC channel was implemented in a FPGA which also received the pulses from the trackball and calculated actual position. A SDLC core was purchased and modified for this application.

Value Added or Technologies Applied

• Specification Development
• Product Architecture and IP Evaluation/Acquisition
• VHDL Development
• PCB Design and Implementation
• Product Mechanical Packaging Design and Implementation
• Test Software Development for Validation
• Prototyping and Validation

Project

Portable Bench Top Test System

Application

Shipboard Control System

Customer Need

Sailors aboard nuclear-powered submarines and ships require the ability to fully test electronic assemblies prior to installing in an operating system. AVID was requested to develop fully automated portable testers that duplicate the factory acceptance testing of 10s of different electronic assemblies. These testers need to be rugged for shipboard uses as well as take up as little physical space as possible.

AVID's Solution

AVID developed a chassis system which included self-storing characterization boards for each unique board to be tested. Various PC programmable test and measurement equipment was used to simulate inputs and monitor outputs. A master test executive PC application program was developed to run the tests and included step by step instructions, pictures, and test logging. The specific test sequence and acceptance criteria are defined by an Excel spreadsheet which allows non-programmers to easily modify the steps or parameters. A final compile function allows the Excel sequence and limits to be built into a single run-time executable to prevent unauthorized changes.

Value Added or Technologies Applied

• Test Specification/System Specification
• Hardware, Mechanical, PC Application Design
• System Prototype and Validation.
• Build-to-Print Drawings and Documentation
• Six Test Systems for Actual Sea Trials

Project

System Electronics

Application

Volumetric CT/PET/SPECT Diagnostic System

Customer Need

Electronics to detect and collect sensor data from a large photo-sensor array excited by X-rays. Unique requirements were pixel sizes eight times smaller than previous generation systems as well as a large XY array instead of the prior single slice.

AVID's Solution

In addition to the quantity and execution speed that pushed the electronic design, there were also major challenges from power, signal distribution, and thermal management that needed to be addressed. Advanced packaging was required to achieve the circuit density, and special consideration for the mechanical design included the ability to remove heat from the electronics. A mass amount of parallel signal processing was implemented as stand-alone subassemblies with dedicated ASICs, DSPs, communication interfaces to centralized memory arrays, and power conversion. The memory data on the rotor side was then organized and packed for transmission across the rotating interface and stored on the stator side for use by the post processing imaging engines. The front end processing subassemblies provided a means for modular testing and system maintenance.

Value Added or Technologies Applied

• Electronic System Requirements/Architecture
• Data Flow Diagrams. Memory Architecture and Management, Speed Performance Analysis
• Hardware Design; Advanced Packaging Concepts (Ceramic Carriers, COB, Rigid/Flex)
• In-Line Real-Time Signal Processing and Combination, VHDL and DSP Techniques
• Thermal Management; Fluid-Based and Thermo-Electric Cooling
• High-Speed Data Transfer Method (20GBps) Across a Rotating Interface
• Proof of Concept Modeling
• Manufacturing Techniques and Process Research/Definition

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

Project

Control Hardware

Application

Commercial Inkjet Printer

Customer Need

Mass marketing requires high-speed printing for customized printed materials and addressing. Multiple print heads are required along with strict timing based on material position. Ink jet print heads take serial bit streams containing the commands and data. PCs are used as the main print job driver; however, specialized hardware is needed to control the individual print heads. In this case, a PCI card was desired that would control up to four independent print heads. Each head is performing a different print job based on its location on the media transport system.

AVID's Solution

AVID started with the customer’s system architecture and implemented a FPGA-based solution in a PCI card form factor. Due to high speed signals, careful attention was paid to board impedance, trace lengths and routing, and termination techniques to insure signal integrity. The FPGA implemented the critical timing of the signals, data buffers for print head data, and interfaced to a processor used for overhead control. Diagnostics were included to assist with system troubleshooting. AVID used simulation to verify the VHDL implementation as well as performed verification testing on prototype hardware.

Value Added or Technologies Applied

• System Architecture Review / Planning
• Hardware Redesign / New PCB Layout
• VHDL Development / Simulation / Verification
• Prototyping and Validation
• Management of an Engineering Build for Software Development and Field Trials
• Manufacturing Engineering Support for Full Production

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

Project

Control System Electronics

Application

Nuclear Power Plant

Customer Need

Nuclear power plants are controlled by the NRC and have strict requirements for the control instrumentation and any changes to it. The life of these systems outlasts the availability of replacement components. Our customer was faced with system obsolescence and required form, fit, and functional replacements of eight different logic boards that were built with outdated technology. All new designs require extensive review and test prior to any possible commissioning. All design work must follow documented procedures and result in a complete design package.

AVID's Solution

AVID implemented the control logic which was previously done with basic gates and 15V logic, in a CPLD device with discrete transistors to interface and drive the higher voltage at the I/O connector. Additionally, AVID invented a proprietary real-time diagnostic feature that performs a continuous health check on the board and reports any electronic failures. This check is performed by a separate CPLD and offers to eliminate the requirement for periodic manual testing of boards by instrument technicians, which requires the boards be removed from an operating system to run the test. AVID also designed suitcase encased board testers which allowed field technicians and production personnel to completely test a board for proper operation.

Value Added or Technologies Applied

• Hardware and CPLD Architecture, Continuous Self Test
• Hardware and CPLD Design
• Design and Production Documentation
• Prototype and Validation, Test Result Reports
• Portable Tester Development and Documentation, Test Procedures
• Engineering Build of Qualification Units
• Manufacturing Support

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

Project

Automated Production Tester

Application

Spark Plug Production Line

Customer Need

A production tester of spark plugs which can be programmed for over 100 different product models and interfaces to a PLC used to control the production line. Both PLC feedback and visual pass-fail indication was required.

AVID's Solution

The primarily pass-fail measurement for spark plugs is impedance. This measurement is made by firing a high voltage across the plug, measuring instantaneous voltage and current, and calculating the impedance. This impedance is compared to an acceptance range defined by the model. AVID created a tester which develops 1000VDC and provides all required isolated measurement circuitry. A user interface with LED and LCD displays was designed for monitoring the tester operation and results, configuration and setup, and tester calibration with common bench instruments. A serial protocol was implemented which triggers the test start from the PLC and provides the test results back to use for product binning.

Value Added or Technologies Applied

• Hardware, Firmware Design
• Mechanical Packaging
• Prototype and Validation
• Production Test and Periodic Calibration Procedures, Fixtures
• Tester Production and Life Cycle Support

Project

Distributed Temperature Control System

Application

Production Process Control

Customer Need

Our customer supplied custom designed and thermal blankets which were fitted to piping in process plants. Previous installations by our customer required a central temperature controller with home run wiring to connect RTDs and AC controls to thermal blankets used to maintain process pipe at required temperatures. The goal was to develop a low cost distributed system that performed stand-alone control and eliminated long wiring. User installation and setup needed to be simple.

AVID's Solution

AVID developed a single channel temperature controller which provides ON/OFF AC control to the thermal blankets. Since AC is needed at the blanket anyway, a short pig-tail wire was all that is required. A separate short connection to a local RTD connects via pre-wired connector. The controllers are designed to daisy-chain from a single User Interface Panel. Device addressing is automatic. A common off-the-shelf CAT5 cable provides power and communications to the chain. Up to 40 controllers can be chained together. The User Interface allows setup of a multi-zone system, monitors the system operation and alarms, and provides the ability to interface to a computer for data logging or other database functions.

Value Added or Technologies Applied

• System Specification / System Architecture
• Hardware and Firmware Design for Local Controllers and User Interface
• Industrial Design and Mechanical Packaging
• Prototype and Validation
• Production Test System Development
• Manufacturing Support and Product Life Cycle Management

Project

Optical Inspection System

Application

Bottle Production

Customer Need

An optical inspection system that quickly identifies product flaws on a high-speed production line. Our customer developed proprietary techniques to detect these flaws by using the reflected light intensity. The final system required tightly packaged electronics for the optical source and the detector, which could accurately and reliably sense these variations in the reflected light intensity. Customer Intellectual Property implemented in a FPGA was to be incorporated in the design.

AVID's Solution

Maintaining a consistent light source was crucial to the proper detection of these flaws. This involved tight regulation of the LED current using closed loop PWM control techniques. As several light sources from different directions were used, any single LED needed ON/OFF control based on system timing. The optical sensing circuit required special care during the component selection and the PCB layout phases to minimize the system noise while still achieving the required amplification and bandwidth required by the high-speed system. The system packaging required the design to be implemented on several small boards, which interfaced together to complete the assembly. Proper partitioning was critical in order to keep the low level signals localized and away from noise sources. Careful layout along with simulations, analysis and refinement of the analog circuitry was required to achieve the system performance objectives.

Value Added or Technologies Applied

• Part Selection / System Partitioning
• Hardware and Firmware Design
• Prototype and Validation
• Engineering Build for Evaluation and Field Trials
• Low-Volume Initial Production
• Prototype and Validation
• Production Test System Development
• Manufacturing Support and Product Life Cycle Management

Project

Advanced Electronics

Application

LED Lighting

Customer Need

A sporting series of portable flashlights that combines the latest rechargeable battery technology along with high-brightness white LEDs to give consumers the next level of advanced lighting solutions. The electronics provide the dimming, spot/flood control, and battery chemistry detection, monitoring and recharging functionality. With previous designs, the light dims as the battery voltage declines, but with smart electronics, a constant current can be maintained until the battery is exhausted and needs to be recharged. The electronics need to be small and efficient to fit in a handheld package while minimizing the production cost. Recharging alternatives include AC, vehicle power, and flexible solar panels.

AVID's Solution

Incorporating a switched-mode converter technology, the LED brightness can be maintained while the battery voltage is declining. By implementing a battery gas gauge and intelligent charging algorithms, the Li-Ion batteries can be recharged quickly within safe operating conditions. A variable current limit is implemented for multiple LEDs to control the light intensity and to provide various light patterns. Special thermal techniques including metal clad boards are implemented to address the heat rise of the electronics, and specifically the LED boards.

Value Added or Technologies Applied

• Microprocessor Control for LED Dimming and Smart Charging Algorithms
• Switched Mode Power Conversion to Maximize Light Output even as the Battery Voltage Declines
• Special Charge Algorithms for Quick and Safe Charging, as well as Optimization Depending on the Recharge Power Source
• Metal Clad Boards and Other Mechanical Thermal Packaging for Heat Rise due to Concentrated Power of the LEDs
• AVID Supported the Product Specification with the Client, Completed the Hardware and Firmware Design and Prototyping, Validated the Design, and Supported Introduction to Manufacturing

Project

Control Electronics

Application

Home Air Filter/Purifier

Customer Need

As a high end home air filter, this new product required intelligence for functions such as variable fan speed control, dust sensing, filter life monitor, remote control interface. The system has the ability to automatically adjust the fan speed based on the dust in sampled air in addition to a user settable manual mode. A special high speed “turbo” mode is also included for maximum air cleaning. A user panel of LEDs and pushbuttons provides for system monitor and user adjustment. Low cost, high reliability is a requirement.

AVID's Solution

A microprocessor-based system was implemented with PWM-controlled output to the fan motor. The micro monitored a dust sensor as well as the user pushbuttons. Control loops were implemented in the firmware for fan speed control. The firmware also controlled the operating modes, kept track of filter life, illuminated user panel LEDs and interfaced via an IrDA port to a remote control device and allows for field upgrades.

Value Added or Technologies Applied

• Electronics Specification
• Hardware/Firmware Design
• Prototype and Validation
• Manufacturing Engineering Support, Production Test Procedure

Project

Li-Ion Battery Control/Charger Electronics

Application

Portable Appliance

Customer Need

The consumer appliance in this case is powered from a removable battery pack which requires a charger. A spare pack may be kept charged and a quick swap allows the user to continue use. The removable pack may also be used to power different appliances. Li-Ion batteries require special care to prolong their life as well as prevent dangerous flare up. Low cost is a key driver in the design.

AVID's Solution

A low cost microcontroller was implemented to perform the battery monitoring and charging functions. Provisions for various use cases involving plugging and unplugging, erratic contact during insertion, power draw from the battery during charge cycles, and temperature monitoring for safe operation were implemented. Additionally, a communication channel was added to allow specific battery data to be transferred for status indication.

Value Added or Technologies Applied

• Hardware and Firmware Architecture
• Hardware and Firmware Design and Documentation
• Prototype and Validation
• Production Test System Development
• Manufacturing Support
• Manufacturing Techniques and Process Research/Definition

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

Project

Product Design and Production

Application

Portable Reminder Device

Customer Need

There are situations relating to a person’s job that depend on certain tasks, a repetitive or single event, to occur on time. As people’s jobs take on more and more, remembering a multitude of tasks and specific times becomes more difficult. A very simple reminder device was requested that could be customized with special menu options for specific jobs. This is not a PDA and the targeted user does not need be technology driven. Also, cost must be low to make this a viable option for every user.

AVID's Solution

AVID took the customer concept and created the complete product design. This includes functional and physical implementation. AVID performed all of the electrical, mechanical and firmware design, as well as created a PC application and a web application to support upgrades and custom configurations. A touch screen provided a simple user interface. A USB port was used for battery charging and downloads from the PC. We set up the production house and provided all of the manufacturing engineering support required for ramping up the product to full production.

Value Added or Technologies Applied

• Design Architecture, Component Selection, Battery and Touch Screen
• Hardware, Firmware and Mechanical Design
• PC Application / Web Application Development
• Prototype and Validation
• Manufacturing Engineering Support; Plastic Part Tooling, Production Test, AVL Management, Assembly, Process Review and Support

Project

Motor Controller

Application

Commericial Vehicle Electronics

Customer Need

An 8HP 3-Phase Motor is used to drive an air compressor for a large hybrid vehicle breaking system. A motor controller is required to control motor speed with a 300VDC to 420VDC input bus. The product must meet automotive requirements for reliability and ruggedness.

AVID's Solution

Challenges for this project included high instantaneous switching currents, critical timing for phase switching, thermal protection, and addressing the parasitic parameters of the switching devices and other system components. Excessive noise must be eliminated as it causes errant operation and ultimately component failures. Three half bridge drivers commutate at 200 KHz. A high side PWM switches at 20 KHz to control speed. The design is partitioned into two boards; a low voltage digital control board and a high voltage driver board. The LV board comprises a DSP for system control, DC/DC supply, inputs for motor speed, pressure and temperature, and outputs for the PWM drive and valve control. The HV board contains three half bridge IGBT low side drivers and FET high side drivers. Low voltage power isolation is needed for the FET drive and sensor circuits. Thermistor temperature sensing and protection was included for each phase. The layout required hand-crafted planning to accommodate the ~20A currents, isolation requirements, and tight loops to minimize system noise and emissions.

Value Added or Technologies Applied

• Review and Re-Design of Customer Circuitry to Address Problems with Operation, Noise, and Component Failures
• Parallel Paths for Different System Architectures to Determine Optimum Implementation
• Prototyping and Bench Testing of Critical Sections of Each
• Hand-Crafted Layout and Board Partitioning Optimization
• Final Design Implementation, PCB Layout, Prototype, and Bench Testing
• Engineering Build of 20+ Units for Customer Validation and Field Testing
• AVID Support of the Customer Testing, Validation, Field Trials, Production Readiness

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

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 MIZRA 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 MIZRA 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

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