Fixed code not working

ch4/controller.sv

@@ -1,3 +1,5 @@
+`timescale 1ns/1ps
+
 module controller #(parameter N=21)
    (input logic clk,
     input logic reset,
@@ -25,6 +27,8 @@ always_ff @(posedge clk, posedge count_reset, posedge reset) begin
 		state <= next_state;
 end
 
+logic [2:0] sensors_lmr;
+
 assign sensors_lmr = {sensor_l, sensor_m, sensor_r};
 
 always_comb begin
@@ -54,36 +58,48 @@ always_comb begin
 			motor_l_direction = 1;
 			motor_r_reset = 0;
 			motor_r_direction = 0;
+
+			next_state = state;
 		end
 		Gentle_l: begin
 			motor_l_reset = 1;
 			motor_l_direction = 0;
 			motor_r_reset = 0;
 			motor_r_direction = 0;
+
+			next_state = state;
 		end
 		Sharp_l: begin
 			motor_l_reset = 0;
 			motor_l_direction = 0;
 			motor_r_reset = 0;
 			motor_r_direction = 0;
+
+			next_state = state;
 		end
 		Gentle_r: begin
 			motor_l_reset = 0;
 			motor_l_direction = 1;
 			motor_r_reset = 1;
 			motor_r_direction = 0;
+
+			next_state = state;
 		end
 		Sharp_r: begin
 			motor_l_reset = 0;
 			motor_l_direction = 1;
 			motor_r_reset = 0;
 			motor_r_direction = 1;
+
+			next_state = state;
 		end
 		default: begin
 			motor_l_reset = 1;
 			motor_l_direction = 0;
 			motor_r_reset = 1;
 			motor_r_direction = 0;
+
+			next_state = state;
 		end
 	endcase
 

ch4/inputbuffer.sv

@@ -1,3 +1,5 @@
+`timescale 1ns/1ps
+
 module inputbuffer
    (input logic clk,
     input logic sensor_l_in,

ch4/robot.sv

@@ -1,3 +1,5 @@
+`timescale 1ns/1ps
+
 module robot
    (input logic clk,
     input logic reset,

ch4/robot_tb.sv

@@ -29,6 +29,9 @@ module robot_tb();
    end
 
    initial begin
+    $dumpfile("output.vcd");
+    $dumpvars;
+
      #0ms;  sensors = 3'b000; // Forward
      #70ms; sensors = 3'b001; // Gentle left
      #40ms; sensors = 3'b010; // Forward
@@ -37,6 +40,8 @@ module robot_tb();
      #40ms; sensors = 3'b101; // Forward
      #40ms; sensors = 3'b110; // Sharp right
      #40ms; sensors = 3'b111; // Forward
+
+     #40ms; $finish;
    end
 
 endmodule