eecs270.org

Project 2A: Robbie

Project 2B: Renee

Component	Points
Autograder	25
Lab Signoff	25
Total	50

Due Date: January 30, 2026 at 11:59 PM

Before Starting

Helpful resources:

• Combinational Verilog Reference
• Projects Overview
• Comparators: Session 4: Positive Binary Numbers

Starter Files

Project2A.v TestBench2A.v Robbie.v RobbieAction.v SEL1.v wave2A.do

Design Specification

Robbie is a simple robot with three sensors (left, front, right) and two independently-controlled wheels. Each sensor outputs 1 when it detects the beacon in its cone, and 0 otherwise. Each wheel receives a 1 to move forward or 0 to stop. Robbie drives straight when both wheels go forward, stops when both are stopped, and turns toward the stopped wheel when only one is moving.

Figure 1: Robbie

Figure 2: Project 2A interface, module decomposition, and module instantiation graph

Robbie’s behavior:

• Go forward if the front sensor detects the beacon, or if both the left and right sensors detect the beacon.
• If only the right or only the left sensor detects the beacon, turn toward that sensor.
• If the front sensor and a side sensor both detect the beacon, go forward.
• Otherwise, stop.

The wheel actions are displayed on HEX1 (left wheel) and HEX0 (right wheel) as (forward) or (stopped).

Logic Modules: Robbie and RobbieAction

Robbie interface:

Net	Size	Direction	Description
ls	1 bit	Input	Left sensor
fs	1 bit	Input	Front sensor
rs	1 bit	Input	Right sensor
lw	1 bit	Output	Left wheel (1 = forward, 0 = stopped)
rw	1 bit	Output	Right wheel (1 = forward, 0 = stopped)

The RobbieAction module takes a 1-bit wheel signal and drives a 7-bit HEX display with the appropriate character (F or S).

Top-level: Project2A Module

Project2A interface:

Net	Direction	Physical Description	Correspondence to Robbie
SW[2]	input	left switch	ls
SW[1]	input	middle switch	fs
SW[0]	input	right switch	rs
HEX1[6:0]	output	left 7-segment display	left wheel action
HEX0[6:0]	output	right 7-segment display	right wheel action

Design Notes and Hints

• Robbie’s design must be specified in structural Verilog.
• The RobbieAction module should display if the wheel is moving forward or if it is stopped.
• HEX displays are active low: drive a segment to 0 to turn it on.
• The SEL1 module from Project 1 may be reused inside RobbieAction.

Deliverables

File Name	Task	Testing Process	Grading Process
Robbie.v	Implement Robbie control logic in structural Verilog	ModelSim	Autograder
RobbieAction.v	Display wheel action on a HEX display	ModelSim	Autograder
SEL1.v	1-bit 2-to-1 selector (reused from Project 1)	ModelSim	Autograder
TestBench2A.v	Write test cases for the Robbie module	ModelSim	Autograder
Project2A.v	Connect Robbie to FPGA switches and HEX displays	LabsLand	Signoff

To ensure that your design works with the Autograder, do not modify file names, module names, or interfaces for any of the starter files. All files must be submitted to the Autograder for grading and feedback.

The signoff will be conducted in your assigned lab sections the week after the project deadline.