Radio Antenna Turntable System (RATS) Rhonda Blair John Carroll Cameron McKay Pierce Ruggles

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Background Table Mountain Turntable Facility (TMTF)

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Turntable Pictures

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Funding Sponsored by US Department of Commerce

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Requirements Precise position/speed control Remote operation via Telnet Reliability in harsh environment Maintainability

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Block Diagram Ethernet-to-Serial Interface Master Controller Optical Encoder (RS-422) RS-422 Translation 20x4 Character LCD (Parallel) DAC (SPI) and Buffer Motor Controller Turntable Motor Internet

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Block Diagram Ethernet-to-Serial Interface Master Controller Optical Encoder (RS-422) RS-422 Translation 20x4 Character LCD (Parallel) DAC (SPI) and Buffer Motor Controller Turntable Motor Internet

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Block Diagram Purchased components: –Ethernet-to-Serial Interface –20x4 Character LCD (Parallel) –Optical Encoder (RS-422) –DAC –Motor Controller –Turntable Motor

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Block Diagram Built components: –Master Controller HC11E1 Microcontroller 32k Flash (program storage) 32k SRAM –Buffer, other supporting hardware for DAC –RS-422 Translation board –Power board (+15V,-15V,+5V)

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Testing Modular design for easy testing/construction –Power supply –Encoder –Master Controller –Motor/DAC/Buffers

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Testing Turntable model –Allows testing in Capstone lab –If TMTF not operational, allows for a demonstration on expo day

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Project Goals For Expo: –Functioning model –Wire-wrapped prototype –Possible implementation at TMTF End of Summer: –TMTF fully operational –PCBs made –Spare boards configured/populated

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Economic Aspects/Sustainability Limited market (1 customer) Multiple PCBs built for sustainability and easy maintenance Remotely-upgradeable firmware Expensive, exotic components by necessity –For reliability, precision, and power reasons –Encoder, motor controller, motor

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Environmental Impact Low impact because of low production volume Possible noise issues when operating turntable –Located on 4 square miles of restricted land –May anger nearby residents and llamas –However, not feasible to replace turntable

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Manufacturability Wide temperature range components –Outdoor operation year-round High-accuracy components –DAC, Optical Encoder Tested on a scale model before TMTF

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Safety Emergency stop feature No turntable motion without explicit user request Extensive power-on self test Fail-safe DAC (defaults to ‘stop’) Watchdog timer

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Schedule

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Risks and Contingencies Risks –Wire-wrap prototype –Software development/debugging –Turntable model Solutions –Schedule has extra time for risky tasks –Can resort to only doing basic functionality for expo, complete the rest over the summer

Radio Antenna Turntable System (RATS) Preliminary Design Review January 29, Questions?