Design Constraints Analysis

1. Design Constraints Analysis Team 15

2. PSSCs • An ability to measure chlorine concentration, water temperature, and pH with an accuracy of ±5% • An ability to dispense measured amounts of regulatory chemicals into a pool. • An ability to log chlorine concentration, water temperature, and pH data collected over a 30-day period in nonvolatile memory. • An ability to display data logs and configure operating parameters, both locally and remotely. • An ability to detect potentially hazardous chemical concentration levels and sound a local alarm in response and send an E-mail alert.

3. Controller Design Constraints • Controller: • Ethernet (and sufficient RAM/Flash) to implement the web server. • Enough memory to save the 30-day log of measurements. • ATDs to sample sensor data. • SPI for LCD display. • Enough I/O pins to control the 7 pumps and 3 sensors. • SCI for debugging/updating. • PWM to implement an alarm for dangerous chemical levels.

4. Power Design Constraints • There will be 8 pumps and a electric heating element. • Power should support the hefty load of the pumps and heating element. • 3.3V is required for the controller. • 5V is required for serial shift register.

5. Other Design Constraints • Need to isolate (optically) pins from pumps due to the high current draw. • Water resistant, design for splashes and waterproof our circuits. • Need of an amplifier to make the alarm effective.

6. Component Selection • MC9S12NE64