EMPLOYER: Circuit Research Labs INC. [More Info]

PROJECT: A multiple function AM/FM Stereo radio incorporating a DSP that decoded the RDS (Radio Data System) sub carrier on FM radio stations into signals for driving moving message signs, paging, traffic information, etc.

NOTE: This is a good example of a single-person project requiring multiple skills.

Project Description: The goal of this project was to produce an AM/FM radio with an integral DSP, with the following characteristics:

• Decode the RDS sub-carrier produced by many FM radio stations and parse the data in real time.
• Control the onboard LCD display and keyboard that allows the user to operate and program the unit.
• Display decoded RDS data on the LCD in the case of traffic reports, paging, etc.
• Control eight integral hardware solid state relays using data sent through RDS.
• Capability of driving moving message signs from data sent through RDS.
• Hi-Fi Stereo output.
• Nine to Fifteen volt dc power input range.
• Integral transmitter modulation level display.

While remote programming of moving message signs was the target market, the versatility of the design opened up a wider market. As the only person on the project my contributions were:

• System design.
• Scheduling.
• Hardware design (ADSP-2105 DSP).
• Software design. (Written in assembly language .
• Programmable logic design and programming (EPLD).
• PCB schematic design & layout.
• Mechanical & packaging design.
• User interface design and programming.
• Technical documentation.
• Testing and troubleshooting .

Accomplishments:

• Authored a real-time multitasking microkernal as the core of the system. This allowed all system functions to operate independently, thus simplifying and reducing the testing time and the number of software bugs encountered.
• Authored a software tool that added missing functionally to the assembler in use and reduced code generation time by approximately a factor of three.
• The system worked well and was successfully tested driving a moving message sign.