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1 -BRAT Biped Autonomous Tutorial
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25 -
26 - <!-- Header -->
27 - <div style="padding: 0.5rem 0 1rem 0; display:flex; flex-wrap:wrap; gap:1.5rem; align-items:flex-start;">
28 - <div style="flex:1 1 300px;">
29 - <h1 class="asm">Biped BRAT Autonomous Tutorial</h1>
30 - <p><b>Updated December 20, 2011</b></p>
31 - <p><span class="asm-warning">Safety first!</span> Wear eye protection and never touch a powered robot!</p>
32 - <p><b>Hardware required:</b> Bot Board II, BASIC Atom Pro 28, Sharp GP2D12 sensor, Buffered 2-Axis Accelerometer (DE-11).</p>
33 - <p><b>Software &amp; downloads:</b></p>
34 - <ul style="padding-left:1.2rem; margin-top:0.25rem; line-height:1.8;">
35 - <li>BASIC Micro Studio</li>
36 - <li><a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/bratosf3.zip">BRAT Servo Offset Finder Program v3</a></li>
37 - <li><a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat1.zip">Autonomous Walk Code</a></li>
38 - <li><a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat2.zip">Autonomous GP2D12 Code</a> — Videos: <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/avoid01.mpg">Avoiding obstacle</a> · <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/break01.mpg">Taking a break</a> · <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/walkaway.mpg">Proximity beeps</a></li>
39 - <li><a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat3.zip">Autonomous 1-Axis Accelerometer Code</a> — Video: <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/getup01.mpg">Getting up front and back</a></li>
40 - <li><a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat4.zip">Autonomous 2-Axis Accelerometer Code</a> — Video: <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/getup02.mpg">Getting up front and side</a></li>
41 - </ul>
42 - </div>
43 - <div style="text-align:center; flex:0 1 280px;">
44 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/brat00.jpg" style="max-width:100%; border:1px solid #ccc; border-radius:4px;">
45 - <p style="font-size:12px; color:#666; margin-top:0.3rem;"><b>Biped BRAT.</b></p>
46 - </div>
47 - </div>
48 -
49 - <!-- Step 1 -->
50 - <div class="asm-step">
51 - <div class="asm-step-header">
52 - <div class="asm-step-name">Autonomous — Verify Servo Channel Connections</div>
53 - <div class="asm-step-num">Step 1 / 10</div>
54 - </div>
55 - <div class="asm-step-body">
56 - <div class="asm-step-text">
57 - <p>Make sure your servos are plugged into the appropriate channels per Table 1. Note: P9 is used by the speaker and cannot be used for a servo.</p>
58 - </div>
59 - <div class="asm-step-figure" style="flex: 0 1 auto;">
60 - <table class="ref-table" style="width:auto;">
61 - <tr><th>Bot Board I/O</th><th>Connection</th></tr>
62 - <tr><td>P4</td><td>Left Ankle</td></tr>
63 - <tr><td>P5</td><td>Left Knee</td></tr>
64 - <tr><td>P6</td><td>Left Hip</td></tr>
65 - <tr><td>P7</td><td>Right Ankle</td></tr>
66 - <tr><td>P8</td><td>Right Knee</td></tr>
67 - <tr><td>P10</td><td>Right Hip</td></tr>
68 - </table>
69 - <span style="margin-top:0.4rem;">Table 1.</span>
70 - </div>
71 - </div>
72 - </div>
73 -
74 - <!-- Step 2 -->
75 - <div class="asm-step">
76 - <div class="asm-step-header">
77 - <div class="asm-step-name">Autonomous — Configure Bot Board II Jumpers</div>
78 - <div class="asm-step-num">Step 2 / 10</div>
79 - </div>
80 - <div class="asm-step-body">
81 - <div class="asm-step-text">
82 - <p>Set the Bot Board II jumpers per Table 2. The VS to AX0 jumper enables the program to monitor servo battery voltage — when the battery is low the robot can beep a warning. Refer to Figure 2 for the jumper layout.</p>
83 - </div>
84 - <div class="asm-step-figure" style="flex: 0 1 auto;">
85 - <table class="ref-table" style="width:auto; margin-bottom:0.5rem;">
86 - <tr><th colspan="2">Bot Board II Jumper Settings (Table 2)</th></tr>
87 - <tr><td>Enable</td><td>A, B, and C buttons</td></tr>
88 - <tr><td>5V</td><td>I/O Group 0–3</td></tr>
89 - <tr><td>VS</td><td>I/O Groups 4–7 and 8–11</td></tr>
90 - <tr><td>Enable</td><td>SPKEN (Speaker Enable)</td></tr>
91 - <tr><td>Enable</td><td>VS (Servo Voltage) to AX0 (P16)</td></tr>
92 - </table>
93 - <span>Table 2.</span>
94 - </div>
95 - </div>
96 - <div class="asm-fullwidth">
97 - <p style="font-weight:bold; margin-bottom:0.4rem;">Figure 2 — Jumper diagram</p>
98 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/autobrat.gif" style="max-width:100%; border:1px solid #ccc; border-radius:4px;">
99 - </div>
100 - </div>
101 -
102 - <!-- Step 3 -->
103 - <div class="asm-step">
104 - <div class="asm-step-header">
105 - <div class="asm-step-name">Autonomous — Find Servo Offsets</div>
106 - <div class="asm-step-num">Step 3 / 10</div>
107 - </div>
108 - <div class="asm-step-body">
109 - <div class="asm-step-text">
110 - <p>Download and install BASIC Micro Studio. Download the <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/bratosf3.zip">BRAT Servo Offset Finder Program v3</a>, load it into the IDE, and program the Atom Pro. Then use the buttons to find offsets:</p>
111 - <ul style="margin-top:0.5rem; padding-left:1.2rem;">
112 - <li><b>A</b> — decrease servo offset by 5µs</li>
113 - <li><b>C</b> — increase servo offset by 5µs</li>
114 - <li><b>B</b> — change which servo is being adjusted, and save offsets (order shown in Figure 3)</li>
115 - </ul>
116 - <p>If the Speaker is enabled, pressing B plays a tone that rises in pitch as you cycle through servos, and drops to a longer tone when returning to Start.</p>
117 - </div>
118 - <div class="asm-step-figure">
119 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/bratosf3.jpg">
120 - <span>Figure 3 — Servo offset finder sequence.</span>
121 - </div>
122 - </div>
123 - </div>
124 -
125 - <!-- Step 4 -->
126 - <div class="asm-step">
127 - <div class="asm-step-header">
128 - <div class="asm-step-name">Autonomous — Calibrate Robot to Neutral Position</div>
129 - <div class="asm-step-num">Step 4 / 10</div>
130 - </div>
131 - <div class="asm-step-body">
132 - <div class="asm-step-text">
133 - <p>Place the robot as close to neutral as possible and turn it on. It should hold the neutral position resembling Figures 4-1 through 4-3. If any joint is off by more than 15°, remove the servo horn, rotate to align, and reattach. Use the A, B, and C buttons to fine-tune.</p>
134 - <p>Note: HS-422 hip servos may oscillate when the robot is lifted off the ground — this is normal and minimal when walking. Higher voltage makes oscillations worse. Higher-power servos (HS-475, HS-485, HS-645) do not exhibit this.</p>
135 - <p><span class="asm-warning">After adjusting all servos to match Figures 4-1 through 4-3, pressing B saves the offset values to the Atom Pro's EEPROM.</span></p>
136 - </div>
137 - <div class="asm-figures">
138 - <div class="asm-step-figure">
139 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/brat10.jpg">
140 - <span>Figure 4-1 (front view).</span>
141 - </div>
142 - <div class="asm-step-figure">
143 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/brat07.jpg">
144 - <span>Figure 4-2 (side view).</span>
145 - </div>
146 - <div class="asm-step-figure">
147 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/brat04.jpg">
148 - <span>Figure 4-3 (rear view).</span>
149 - </div>
150 - </div>
151 - </div>
152 - </div>
153 -
154 - <!-- Step 5 -->
155 - <div class="asm-step">
156 - <div class="asm-step-header">
157 - <div class="asm-step-name">Autonomous — Load Basic Walk Code</div>
158 - <div class="asm-step-num">Step 5 / 10</div>
159 - </div>
160 - <div class="asm-step-body">
161 - <div class="asm-step-text">
162 - <p>Download the <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat1.zip">BRAT Autonomous Walk Code</a>, load it into the IDE, and program your BRAT.</p>
163 - <p>The BRAT will now walk autonomously following this sequence: walk × 3, turn, long-stride × 2, kick, turn, stop. To customise behavior, modify the code between the labels "main" and "move", or create new sequences following the format below the "move" label.</p>
164 - </div>
165 - </div>
166 - </div>
167 -
168 - <!-- Step 6 -->
169 - <div class="asm-step">
170 - <div class="asm-step-header">
171 - <div class="asm-step-name">Autonomous — Mount &amp; Connect GP2D12 Sensor</div>
172 - <div class="asm-step-num">Step 6 / 10</div>
173 - </div>
174 - <div class="asm-step-body">
175 - <div class="asm-step-text">
176 - <p>Use double-sided tape to attach the GP2D12 sensor to the BRAT's head area, facing the front. Exact position is not critical. Plug the sensor into the channel shown in Table 6.</p>
177 - <table class="ref-table" style="width:auto; margin-top:0.5rem;">
178 - <tr><th>Bot Board I/O</th><th>Connection</th></tr>
179 - <tr><td>P19 (AX3)</td><td>GP2D12 Sensor</td></tr>
180 - </table>
181 - <p style="font-size:11px; color:#666; margin-top:0.3rem;">Table 6.</p>
182 - </div>
183 - <div class="asm-step-figure">
184 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/bratsens.jpg">
185 - <span>Figure 6 — GP2D12 sensor mounted.</span>
186 - </div>
187 - </div>
188 - </div>
189 -
190 - <!-- Step 7 -->
191 - <div class="asm-step">
192 - <div class="asm-step-header">
193 - <div class="asm-step-name">Autonomous — Load GP2D12 Obstacle Avoidance Code</div>
194 - <div class="asm-step-num">Step 7 / 10</div>
195 - </div>
196 - <div class="asm-step-body">
197 - <div class="asm-step-text">
198 - <p>Download the <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat2.zip">BRAT Autonomous GP2D12 Code</a>, load it into the IDE, and program your BRAT.</p>
199 - <p>The BRAT can now roam without bumping into obstacles. The sensor is read before each step. A short low beep means nothing is detected; the beep rises in pitch as objects get closer. At ~8" the robot backs up one step, turns left two steps, then continues. A looping counter periodically puts the robot into a resting position. LEDs illuminate based on the current command.</p>
200 - <p>Videos: <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/avoid01.mpg">Avoiding obstacle</a> · <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/break01.mpg">Taking a break</a> · <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/walkaway.mpg">Proximity beeps</a></p>
201 - </div>
202 - </div>
203 - </div>
204 -
205 - <!-- Step 8 -->
206 - <div class="asm-step">
207 - <div class="asm-step-header">
208 - <div class="asm-step-name">Autonomous — Mount &amp; Connect Accelerometer</div>
209 - <div class="asm-step-num">Step 8 / 10</div>
210 - </div>
211 - <div class="asm-step-body">
212 - <div class="asm-step-text">
213 - <p>Use double-sided tape to attach the accelerometer to the BRAT's head area. <span class="asm-warning">Axis orientation is critical — follow the orientation shown in Figure 8 exactly.</span> Plug the sensor into the channels shown in Table 8.</p>
214 - <table class="ref-table" style="width:auto; margin-top:0.5rem;">
215 - <tr><th>Bot Board I/O</th><th>Connection</th></tr>
216 - <tr><td>P17 (AX1)</td><td>Accelerometer Y Axis (front-to-back tilt)</td></tr>
217 - <tr><td>P18 (AX2)</td><td>Accelerometer X Axis (side-to-side tilt)</td></tr>
218 - </table>
219 - <p style="font-size:11px; color:#666; margin-top:0.3rem;">Table 8.</p>
220 - </div>
221 - <div class="asm-step-figure">
222 - <img src="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/bratacc.jpg">
223 - <span>Figure 8 — Accelerometer orientation.</span>
224 - </div>
225 - </div>
226 - </div>
227 -
228 - <!-- Step 9 -->
229 - <div class="asm-step">
230 - <div class="asm-step-header">
231 - <div class="asm-step-name">Autonomous — Load 1-Axis Accelerometer Code</div>
232 - <div class="asm-step-num">Step 9 / 10</div>
233 - </div>
234 - <div class="asm-step-body">
235 - <div class="asm-step-text">
236 - <p>Download the <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat3.zip">BRAT Autonomous 1-Axis Accelerometer Code</a>, load it into the IDE, and program your BRAT.</p>
237 - <p>This program uses only the Y Axis to detect front-to-back tilt — the BRAT can tell when it has fallen forward or backward and get back up. The X Axis will be incorporated in Step 10.</p>
238 - <p>Video: <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/getup01.mpg">Getting up front and back</a></p>
239 - </div>
240 - </div>
241 - </div>
242 -
243 - <!-- Step 10 -->
244 - <div class="asm-step">
245 - <div class="asm-step-header">
246 - <div class="asm-step-name">Autonomous — Load 2-Axis Accelerometer Code</div>
247 - <div class="asm-step-num">Step 10 / 10</div>
248 - </div>
249 - <div class="asm-step-body">
250 - <div class="asm-step-text">
251 - <p>Download the <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/abrat4.zip">BRAT Autonomous 2-Axis Accelerometer Code</a>, load it into the IDE, and program your BRAT.</p>
252 - <p>This version adds the X Axis for side-to-side tilt detection — if the BRAT falls onto its side it will roll over to get back up. It also includes an improved "get up from back" routine for robots with heavy cabling, and a "startled" behaviour: if the BRAT is resting and the GP2D12 suddenly detects an object, it will lean back and beep.</p>
253 - <p>Video: <a href="https://wiki.lynxmotion.com/info/wiki/lynxmotion/download/servo-erector-set-robots-kits/ses-v1-robots/ses-v1-bipeds/brat-biped-autonomous/WebHome/getup02.mpg">Getting up front and side</a></p>
254 - </div>
255 - </div>
256 - </div>
257 -
258 -</div>
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