CS 278 Final Project Overview The final project for CS278 may be a digital system design of your own choosing. The following project serves as the “default” project, meaning that you may simply choose to do this one if you don’t have any specific ideas of your own. If you choose to do a project different from this one, then be sure to complete and turn in the items listed under the section “Assignment” below. This project will provide you with the opportunity to gain experience with a fairly complex design from an engineering style specification. Specification This project involves the design of a custom FPGA-based (Altera FLEX 10K70) traffic signal controller for the intersection of County Road II and Hwy 93. The intersection is due to be arranged as follows: Hwy 93 will be a major North-South road of four lanes, with two lanes in each direction. One of the lanes in each direction turns into a left turn lane near the intersection. Northbound and Southbound traffic is regulated by two individually controlled traffic signals. Each signal consists of a 3-way standard traffic light (Red, Yellow, Green) and a 2-way left-turn arrow (Yellow and Green). There are sensors buried in the road surface under each of the left turn lanes. The sensors are active high. County Road II is a smaller two lane road, with one lane in each direction. Eastbound and Westbound traffic is controlled by two stoplights that are controlled together (i.e. they are always identical). Each signal consists of a 3-way standard traffic light (Red, Yellow, Green). There are sensors buried in the road surface under each of the lanes near the intersection. The sensors are active high.There is an additional sensor in the system for detecting emergency vehicles. This sensor is mounted on top of the traffic signals such that it can detect the strobe light on emergency vehicles as they approach the intersection from any direction. The sensor can detect the emergency vehicles at least 10 seconds before the vehicle reaches the intersection. General Requirements The use of the word shall indicates that the requirement is mandatory. The use of the word should indicates that the requirement is strongly recommended by the originator of the requirement. The use of the word may indicates that the requirement is optional. • The traffic control system shall control all of the traffic lights at the intersection using a combination of sensor-based control and timed control. • There shall be a timer in the system that can be used to provide timing for certain light combinations. This timer shall be capable of supporting a minimum of three time intervals: o TS Timer Short 5 seconds o TM Timer Medium 20 seconds o TL Timer Long 40 seconds • The system shall be capable of turning on all of the lights on all of the signals simultaneously for the purpose of easy detection of faulty lighting. The system shall also be capable of simultaneously turning off all of the lights on all of the signals for the purpose of manual traffic control by local police. • The system should be built with expansion in mind. Specifically, the system should support separate control for each of the signals on County Road II. (i.e. they shouldn’t run off the same output.) • If desired the system may also support an optional pedestrian control system. Operational Requirements • North-South traffic on Hwy 93 shall take precedence over all other traffic except for emergency vehicles. That is, the North/South traffic lights shall stay Green unless one of the East/West sensors (or the emergency vehicle sensor) is asserted. Once Green, the North/South traffic lights shall stay Green for a minimum of TL seconds, regardless of the state of the East/West road sensors. • When some East/West sensor on County Road II is asserted, both traffic lights on Hwy 93 shall be cycled to Yellow for TS seconds and then to Red. The East/West signals shall then stay Green for TL seconds before being cycled to Yellow for TS seconds and then back to Red. • The left turn signals shall be operational only at the beginning of any signal change cycle. That is, the Green left turn arrow shall occur immediately after a Red light, and only when the left turn sensor is asserted in that lane. • Emergency vehicles shall take priority over all other traffic. If the strobe detector is asserted, all Green lights shall immediately be cycled to Yellow for TS seconds and then to Red. All lights shall stay Red for a minimum of TM seconds. If the strobe detector is still asserted after TMseconds expires, then the lights shall stay Red for an additional TM seconds (and so forth), until the strobe is deasserted. Assignment To complete this project, you must: 1. Prepare a short (2-5 pages or so) Theory of Operation for your design. This shall be a description/explanation of your design and your implementation strategy. Flowcharts and/or state diagrams are particularly helpful. 2. Provide the source code Verilog and/or schematic capture for your design. 3. Demonstrate the correct operation of your design during finals week (at the latest). Due Dates The full set of assignment components will be due by Thursday, May 13th. Please note that I don’t think it will take you that long (3 full weeks) to complete the project. However, I know that the end of the semester can be a little crazy, so I prefer to be flexible and let you determine when you can best fit it into your other classes’ schedules. If you prefer to get it done before that last week, I’ll be happy to accept it.