1 / 46

Aquatic Life System

Aquatic Life System BECAUSE FISH ROCK Final Design Review - March 24, 2004 Zach Casper, Richard Dunkley, Blake Hunsaker, and Paul Smart ALS Must Maintain/Monitor : Temperature pH Water Level Feeding and Food Level Reservoir Embedded System PC Water Inlet Valve Feeder Temp

benjamin
Download Presentation

Aquatic Life System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Aquatic Life System BECAUSE FISH ROCK Final Design Review - March 24, 2004 Zach Casper, Richard Dunkley, Blake Hunsaker, and Paul Smart

  2. ALS Must Maintain/Monitor: • Temperature • pH • Water Level • Feeding and Food Level Reservoir Embedded System PC Water Inlet Valve Feeder Temp Sensor pH Sensor Heater Water Outlet Valve Drain Water Level Sensors LCD

  3. Aquatic Life System (ALS) • Embedded System • Microcontroller • (MC68HC11E0) • External 32K Memory for • program storage • USB Module for serial interface MC Feeder Motor Control Feed Control Feeder Rotation Counter Food Level Sensor External Memory BQ4011 MA-100 Inlet (Fill) Valve Control Water Level Control Outlet (Drain) Valve Control Water Level Sensors pH Sensor pH Control A/D Converter Temp Sensor Temperature Control Heater LCD • Aquarium / World • 2 Analog Inputs • 4 Digital Inputs • 4 Actuators Outputs • PC user interface and non-PC display USB Module

  4. ALS Embedded System Schematic

  5. External (to board) Circuitry These circuits are not on the printed Circuit board but are necessary for operation This is the reset circuit for the microcontroller This circuit is a temporary solution to our communications problem regarding the use of a virtual com port with the loading programs. This circuit replaces the USB interface with a simpler serial port connection. It will only be used until a suitable loader program can be found will accommodate the USB module.

  6. PCB Layout Using LAYOUT PLUS • 2 Layers + Silkscreen

  7. Printed Circuit Board Unpopulated TOP VIEW BOTTOM VIEW

  8. Motorola MC68HC11E0 • 5 Ports • 8 Channel / 8 bit A/D Converter • Integrated Serial Communications Interface • 16 Bit Address Bus • 8 Bit Data Bus • 4.2V Min HIGH Out, -0.4V Max for LOW Out • 3.5V Min HIGH Input, 5.3V Max HIGH Input • 1.0V Max Low Input, -0.3V Min Low Input

  9. Motorola 68HC11E0 Block Diagram 512 RAM

  10. Microcontroller Assignments Internal Features PORT Assignments 8 Bit Pulse Accumulator Feeder Rotation Counter Outlet Valve Inlet Valve A Feeder Motor Water Heater Food Level Sensor Water Level Sensor Water Level Sensor Memory Chip / LCD Select (Mem: $8000-$FFFF) B Memory Chip / LCD Select (LCD: $4000-$7FFF) Expanded Mode: Address / Data Bus [6:0] ADDR High C DATA / ADDR Low (Memory and LCD) [8:0] D Serial Communication Interface (SCI) RxD TxD USB Module RxD TxD 8 Bit A/D E Temperature Sensor pH Sensor

  11. USB MODULE · Single module High-Speed USB UART solution · Integrated Type-B USB Connector · On-board 6MHz Crystal · External EEPROM on board for USB enumeration data USBMOD3 Motorola 68HC11E0 FTDI FT232BM USB UART IC Rx Tx SCI Interface Tx Rx USB BUS TO PC

  12. LCD MTC-C162DPLY-2N • Displays: • pH • Temperature • Command Memory Locations: • $40xx Write Instruction • $41xx Read Instruction • $42xx Write Data • $43xx Read Data

  13. Automatic Feeder Design Requirements: • Must be controlled by microcontroller • Must be able to dispense food for different amounts of fish • Must be able to dispense food at different intervals if necessary • Needs to sense when food level in feeder is too low

  14. Microcontroller (MC) 0.4V OFF +4.2V ON 0V OFF +3V ON Conditioning Circuit (Relay) • Nutra-matic Feeder • Includes: • Plastic Case • Motor • Gearing 1V Low +3.5V High Switch To Pulse Accumulator 1V Level OK +3.5V Food Low Food Level Sensor 68HC11 Switch Circuit Food goes in here • Feeder Control • 3V for continuous ON • Each full turn will dispense food and • activate the switch • MC activates motor to control the • number of feeder rotations GEARING MOTOR Switch Rear View of Feeder

  15. Feeder Control

  16. Food Level Detector Photocell 3.5V High Feeder Feeder Food Food Food Okay – Photocell blocked from light (High Resistance ~ Open Circuit) Food Low – Photocell exposed (Low Resistance ~ Closed Circuit)

  17. Food • System will be configured to use flake food • Each rotation will drop approximately ¼ teaspoon of food (~1 pinch) – this is equivalent to what 1 average size fish can eat in 2 minutes • These rotations (# and intervals) will occur as specified in GUI by user

  18. Feeder’s Action

  19. Temperature Control Temperature Sensor Signal Conditioning Microcontroller 8 Bit A/D Heater Relay

  20. Temperature Control Requirements: • Must maintain temperature within 3 degrees Fahrenheit of desired setting (76-78 degrees for most fish) • Must avoid rapid fluctuation in temperature (10 degrees in 12 hours)

  21. Temperature Sensor • National Semiconductor LM34CAZ • 1.11 degrees Fahrenheit accuracy • 5-30 VDC supply voltage

  22. Temperature ControlSignal Conditioning

  23. Temperature vs. Voltage

  24. Example A/D Results for Temperature Sensor

  25. Heater • Heating coil in plastic casing • 50 Watts

  26. Relay • 5 VDC coil • 1 Amp contact rating

  27. Heater Control

  28. Water Input/Output Control Water Level Sensors Inlet Valve Microcontroller Outlet Valve pH Sensor

  29. Water Input/Output Control Requirements: • Draining and filling of tank are activated based on readings from pH sensor • Water level will never become too high or too low – 1 inch top level, 5 inches bottom level

  30. Water Level Control Water Source Water Level Sensors Desired Water Level Drain

  31. Water Level Sensors • Simple open/close switch • Small size

  32. Water Level Sensors To Microcontroller Upper Level Sensor – PA0 Lower Level Sensor – PA1

  33. Valves • 120 VAC solenoid • Normally closed • ¼ inch and ½ inch hose connections • Flow rate: .1gal/min.

  34. Valve Control

  35. pH Control pH Sensor Signal Conditioning Microcontroller 8 Bit A/D Valves Relay

  36. pH Sensor Requirements: • Monitor concentration of hydrogen ions in an aqueous solution • 0 to 14 pH range • Fast response time • Accurate readings

  37. Sensor Input Specifications Circular DIN Plug - 5 pin • Pin 1 = Sensor Output • Pin 2 = Not used • Pin 3 = ID Output (not used with most sensors) • Pin 4 = Power (+5VDC) • Pin 5 = GND

  38. The ideal pH electrode • Zero volts output at neutral pH (=7.0) • Positive voltage in acids, pH<7 • Negative voltages in bases, pH>7 • Generates -59.16 millivolts per pH unit at room temperature (="Nernst potential"). Nernst potential: calculation of the exact electrical potential at equilibrium that is generated for a known concentration difference in a specific ion, separated by a membrane permeable to that ion.

  39. pH electrode • 1.75 volts output at neutral pH (=7.0) • Increase by .25 volts/pH level in acids, pH<7 • Decrease by .25 volts/pH in bases, pH>7 • Response time in 1 second

  40. pH ControlSignal Conditioning

  41. pH Level vs. Voltage

  42. Example A/D Results for pH Sensor

  43. Water Quality and pH • If the level of H+ ions increases, the substance is considered an acid and the pH number is below 7. • If the level of OH- ions increases, the substance is considered to be alkaline or base and the pH number is above 7.

  44. Power Considerations

  45. Basic Cost Breakdown Printed Circuit Board – Advanced Circuits $45.00 LCD – hobbyengineering.com $13.50 USB Module – hobbyengineering.com $26.00 MC68HC11E0 – Digikey $10.00 32K RAM Chip – Digikey $10.50 Resistors, Capacitors, Logic Gates, Misc. – ECE Store $20.00 Relays – Radioshack $3.99 x 3 Photocells – Radioshack $3.50 Input/Ouput Water Valves – Online $22.00 x 2 Water Level Sensors – Digikey $10.00 x 2 Temperature Sensor – National Semi $0.00 Feeder – PetSmart $15.00 Time spent working on the ALS – Priceless

More Related