Build a project with the Arty S7 - Line Follower Robot (Part 5) - Project Demo

rahulkhanna

5 Aug 2022

Reasons to switch from Spartan-6 to Spartan-7 FPGAs #1

Build a project with the Arty S7 - Line Follower Robot (Part 1) - Introduction

Build a project with the Arty S7 - Line Follower Robot (Part 2) - Setting up Vivado 2019.2 and Demo program

Build a project with the Arty S7 - Line Follower Robot (Part 3) - Interfacing Sensors and Logic Implementation

Build a project with the Arty S7 - Line Follower Robot (Part 4) - Hardware Assembly

Build a project with the Arty S7 - Line Follower Robot (Part 5) - Project Demo

Build a project with the Arty S7 - Line Follower Robot (Part 6) - Adding sensors to the LFR

Build a project with the Arty S7 - Line Follower Robot (Part 7) - Summary

Project Demo

Before the Hardware assembly, We had connected the IR sensors and their functionality separately. We had connected the IR sensors and motors as shown below:

Arty S7-50	Motor
IO3	in0
IO5	in1
IO6	in2
IO11	in3

Arty S7-50	Sensors
IO0	sen[0]
IO1	sen[1]
IO2	sen[2]
IO4	sen[3]
IO7	sen[4]

Now let's run the IR logic to switch the LEDs.

The hardware is ready to be programmed. Create the file named LFR.sv and implemented the following logic.

module LFR (
input wire logic clk,
input logic [4:0] sen,
output logic [1:0] left_m, [1:0] right_m, [4:0] led
);

logic [4:0] sen_val = 0; // Sensor Val
logic [7:0] in1 = 8'd0;
logic [7:0] in2 = 8'd0;
logic [7:0] in3 = 8'd0;
logic [7:0] in4 = 8'd0;

always_ff @(posedge clk) begin
led <= 5'b00000;

if (sen_val == 5'b00100) begin //fwd
in1 <= 200; in2 <= 0; in3 <= 200; in4 <= 0;
led <= 5'b00100;
end
else if (sen_val == 5'b01000) begin //left
in1 <= 100; in2 <= 0; in3 <= 255; in4 <= 0;
led <= 5'b01000;
end
else if (sen_val == 5'b10000) begin //left
in1 <= 0; in2 <= 0; in3 <= 255; in4 <= 0;
led <= 5'b10000;
end
else if (sen_val == 5'b00010) begin //right
in1 <= 255; in2 <= 0; in3 <= 100; in4 <= 0;
led <= 5'b00010;
end
else if (sen_val == 5'b00001) begin //right
in1 <= 255; in2 <= 0; in3 <= 0; in4 <= 0;
led <= 5'b00001;
end
else if (sen_val == 5'b11100) begin //left
in1 <= 0; in2 <= 255; in3 <= 255; in4 <= 0;
led <= 5'b11100;
end
else if (sen_val == 5'b00111) begin //right
in1 <= 255; in2 <= 0; in3 <= 0; in4 <= 255;
led <= 5'b00111;
end
else if (sen_val == 5'b11111) begin //stop
in1 <= 0; in2 <= 0; in3 <= 0; in4 <= 0;
led <= 5'b11111;
end
end

always_comb begin
sen_val[0] = sen[1] ? 1'b1 : 1'b0;
sen_val[1] = sen[1] ? 1'b1 : 1'b0;
sen_val[2] = sen[2] ? 1'b1 : 1'b0;
sen_val[3] = sen[3] ? 1'b1 : 1'b0;
sen_val[4] = sen[4] ? 1'b1 : 1'b0;
end

pwm m1 (.clk, .duty(in1), .pwm_out(left_m[0]));
pwm m2 (.clk, .duty(in2), .pwm_out(left_m[1]));
pwm m3 (.clk, .duty(in3), .pwm_out(right_m[0]));
pwm m4 (.clk, .duty(in4), .pwm_out(right_m[1]));
endmodule

Finally, we implemented a line follower using Arty S7-50. We will be adding a component to this line follower in the next blog.