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1 | /* |
2 | This program is free software: you can redistribute it and/or modify |
3 | it under the terms of the GNU Affero General Public License as |
4 | published by the Free Software Foundation, either version 3 of the |
5 | License, or (at your option) any later version. |
6 | |
7 | This program is distributed in the hope that it will be useful, |
8 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
9 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
10 | GNU Affero General Public License for more details. |
11 | |
12 | You should have received a copy of the GNU Affero General Public License |
13 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
14 | */ |
15 | |
16 | // define which pins are connected to which components |
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17 | int right_motor_forward_pin = 3; |
18 | int right_motor_backward_pin = 4; |
19 | int right_motor_speed_pin = 5; |
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20 | |
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21 | int right_echo_pin = 6; |
22 | int right_trigger_pin = 7; |
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23 | |
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24 | int left_motor_forward_pin = 8; |
25 | int left_motor_backward_pin = 9; |
26 | int left_motor_speed_pin = 10; |
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27 | |
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28 | int left_echo_pin = 11; |
29 | int left_trigger_pin = 12; |
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30 | |
31 | void on(int pin){ |
32 | digitalWrite(pin, HIGH);} |
33 | |
34 | void off(int pin){ |
35 | digitalWrite(pin, LOW);} |
36 | |
37 | void set_motor(int speed_pin, |
38 | int forward_pin, |
39 | int backward_pin, |
40 | int speed){ |
41 | if(speed > 0){ |
42 | off(backward_pin); |
43 | on(forward_pin);} |
44 | else if(speed < 0){ |
45 | off(forward_pin); |
46 | on(backward_pin); |
47 | speed = -speed;} |
48 | else{ // speed is 0 |
49 | off(forward_pin); |
50 | off(backward_pin);} |
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51 | // since speed has been set positive, no need to check if speed < -255. |
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52 | if(speed > 255){ |
53 | speed = 255;} |
54 | analogWrite(speed_pin, speed);} |
55 | |
56 | void go(int left_motor_speed, int right_motor_speed){ |
57 | set_motor(left_motor_speed_pin, |
58 | left_motor_forward_pin, |
59 | left_motor_backward_pin, |
60 | left_motor_speed); |
61 | set_motor(right_motor_speed_pin, |
62 | right_motor_forward_pin, |
63 | right_motor_backward_pin, |
64 | right_motor_speed);} |
65 | |
66 | int ping(int trigger, int echo){ |
67 | int ping_time = 0; |
68 | // turn off trigger |
69 | off(trigger); |
70 | delayMicroseconds(2); |
71 | // turn on the trigger and leave it on long enough for the |
72 | // sonar sensor to notice |
73 | on(trigger); |
74 | delayMicroseconds(10); |
75 | off(trigger); |
76 | ping_time = pulseIn(echo, HIGH); |
77 | if(ping_time <= 0){ |
78 | ping_time = 3000;} |
79 | // sonar needs some time to recover before pinging again, |
80 | // so make sure it gets enough sleep right here. 50 milliseconds |
81 | delay(50); |
82 | return ping_time;} |
83 | |
84 | void backup(int backup_time){ |
85 | go(-250, -250); |
86 | delay(backup_time);} |
87 | |
88 | void turn_around(int turn_around_time){ |
89 | go(-250, 250); |
90 | delay(turn_around_time);} |
91 | |
92 | void setup(){ |
93 | Serial.begin(9600); |
94 | |
95 | pinMode(right_motor_speed_pin, OUTPUT); |
96 | pinMode(right_motor_forward_pin, OUTPUT); |
97 | pinMode(right_motor_backward_pin, OUTPUT); |
98 | |
99 | pinMode(right_echo_pin, INPUT); |
100 | pinMode(right_trigger_pin, OUTPUT); |
101 | |
102 | pinMode(left_motor_speed_pin, OUTPUT); |
103 | pinMode(left_motor_forward_pin, OUTPUT); |
104 | pinMode(left_motor_backward_pin, OUTPUT); |
105 | |
106 | pinMode(left_echo_pin, INPUT); |
107 | pinMode(left_trigger_pin, OUTPUT); |
108 | |
109 | off(left_motor_speed_pin); |
110 | off(left_motor_forward_pin); |
111 | off(left_motor_backward_pin); |
112 | off(left_trigger_pin); |
113 | |
114 | off(right_motor_speed_pin); |
115 | off(right_motor_forward_pin); |
116 | off(right_motor_backward_pin); |
117 | off(right_trigger_pin);} |
118 | |
119 | void loop(){ |
120 | int left_speed; |
121 | int right_speed; |
122 | |
123 | int forward_speed = 250; |
124 | int stop_speed = 0; |
125 | |
126 | // adjust this number as necessary for your robot. |
127 | // it represents how far the table is from your sonar sensor. |
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128 | // larger values mean larger distance. default is 800 |
129 | int right_max_ping_time_over_table = 800; |
130 | int left_max_ping_time_over_table = 800; |
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131 | int backup_time = 2000; |
132 | // the exact amount of time for turning around might need |
133 | // twerking for your robot. the default value is 3200 |
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134 | int turn_around_time = 3200; |
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135 | |
136 | int actual_left_ping_time = ping(left_trigger_pin, left_echo_pin); |
137 | int actual_right_ping_time = ping(right_trigger_pin, right_echo_pin); |
138 | |
139 | Serial.print("left ping = "); |
140 | Serial.print(actual_left_ping_time); |
141 | Serial.print("\tright_ping = "); |
142 | Serial.println(actual_right_ping_time); |
143 | |
144 | // if the left sonar senses a table, keep driving left side forward, |
145 | // otherwise, stop left side |
146 | if(actual_left_ping_time < left_max_ping_time_over_table){ |
147 | left_speed = forward_speed;} |
148 | else{ |
149 | left_speed = stop_speed;} |
150 | // if the right sonar senses a table, keep driving right side forward, |
151 | // otherwise, stop right side |
152 | if(actual_right_ping_time < right_max_ping_time_over_table){ |
153 | right_speed = forward_speed;} |
154 | else{ |
155 | right_speed = stop_speed;} |
156 | |
157 | // if both sonars detect being off the table, backup and turn around |
158 | // otherwise, go the correct speed for each wheel |
159 | if(actual_left_ping_time >= left_max_ping_time_over_table |
160 | && actual_right_ping_time >= right_max_ping_time_over_table){ |
161 | Serial.println("backing up"); |
162 | backup(backup_time); |
163 | Serial.println("turning around"); |
164 | turn_around(turn_around_time);} |
165 | else{ |
166 | Serial.println("going"); |
167 | go(left_speed, right_speed);}} |