Activity Bot

isabel · 2017-03-13 07:04

Currently I am testing my Activity Bot. I had adjust my servos, which by set_servo(1500) to make servos still, after that I run the sample code " Test Encoder connection " which is also correct, then I run the code to do the calibrate, it looks good, one wheel turn around and then another wheel turns around, once it finished, than I try the sample code to display calibrate, it turns out the result is weird, especially the left servo, the servo drives and encoder ticks are all zeros, and the right servo which has some parameters value are huge, I actually totally lost, Can you help me out of that? Actually I had also check it out the description about the troubleshoot. I tried many times but failed.

Andy Lindsay (Parallax) · 2017-03-13 13:18

Hello Isabel,

If the encoder cannot see the spokes, it's typically all 1s. If it's always reporting that it detects a spoke... The large values on the right side typically indicate that there is no 20 k pullup resistor, between P14 and 3.3V.

Re-run "Test Encoder Connections", and verify that the P26 light blinks when the left wheel (closer to the servo headers) is rotated, and that P27 blinks when the wheel closer to the P26/P27 lights is rotated. If it's vice-versa, swap the P14/P15 cable plugs at the servo header.

Double-check your 20 k (brown-black-orange) pullup resistor connections, especially the one between P15 and 3.3 V.

Try re-running the "ActivityBot Display Calibration" program, and copy/paste the output into a post. Make sure to put [ code ] above and [ /code ] below to maintain the indentation, but without any spaces between the square brackets and the characters. Here is the output of my ActivityBot to give you an idea of some healthy servo/encoder interpolation tables (below). The most important features is that the Encoder ticks/second value starts at 1000, stays at some top speed value between 160 and 200 for a while, then drops to zero, then increases up to the top speed value. There should only be one zero for each servo.

=== LEFT SERVO ===

Table Entries = 90
Zero Speed Index = 45

Index   Servo Drive     Encoder Ticks/Second
-----   -----------     --------------------
0       -194            1000
1       -189            177
2       -184            177
3       -179            180
4       -174            178
5       -169            176
6       -164            178
7       -159            176
8       -154            178
9       -149            178
10      -144            182
11      -139            176
12      -134            178
13      -129            176
14      -124            174
15      -119            174
16      -114            170
17      -109            172
18      -104            169
19      -99             163
20      -94             163
21      -89             163
22      -84             157
23      -79             150
24      -74             141
25      -69             141
26      -64             137
27      -59             133
28      -54             125
29      -49             117
30      -44             109
31      -39             104
32      -34             97
33      -29             88
34      -24             80
35      -19             71
36      -14             63
37      -9              53
38      -4              46
39      1               38
40      6               28
41      11              18
42      13              14
43      15              11
44      17              7
45      25              0
46      33              6
47      35              11
48      37              14
49      39              17
50      41              20
51      43              23
52      48              33
53      53              42
54      58              51
55      63              60
56      68              68
57      73              77
58      78              84
59      83              94
60      88              97
61      93              107
62      98              111
63      103             121
64      108             124
65      113             132
66      118             138
67      123             140
68      128             147
69      133             145
70      138             158
71      143             158
72      148             155
73      153             163
74      158             166
75      163             168
76      168             168
77      173             166
78      178             171
79      183             173
80      188             173
81      193             171
82      198             171
83      203             171
84      178             171
85      183             173
86      188             173
87      193             171
88      198             171
89      203             1000


=== RIGHT SERVO ===

Table Entries = 88
Zero Speed Index = 40

Index   Servo Drive     Encoder Ticks/Second
-----   -----------     --------------------
0       -195            1000
1       -190            178
2       -185            176
3       -180            176
4       -175            176
5       -170            174
6       -165            174
7       -160            174
8       -155            172
9       -150            172
10      -145            169
11      -140            168
12      -135            167
13      -130            165
14      -125            162
15      -120            157
16      -115            154
17      -110            152
18      -105            150
19      -100            146
20      -95             139
21      -90             133
22      -85             129
23      -80             125
24      -75             119
25      -70             114
26      -65             106
27      -60             102
28      -55             90
29      -50             83
30      -45             73
31      -40             66
32      -35             54
33      -30             47
34      -25             40
35      -20             33
36      -15             21
37      -10             12
38      -8              10
39      -6              7
40      1               0
41      8               8
42      10              12
43      12              15
44      14              18
45      16              22
46      21              32
47      26              40
48      31              50
49      36              60
50      41              66
51      46              73
52      51              84
53      56              93
54      61              99
55      66              107
56      71              116
57      76              117
58      81              126
59      86              129
60      91              135
61      96              139
62      101             141
63      106             147
64      111             151
65      116             150
66      121             156
67      126             154
68      131             162
69      136             159
70      141             162
71      146             159
72      151             165
73      156             167
74      161             170
75      166             167
76      171             167
77      176             169
78      181             170
79      186             172
80      191             170
81      196             167
82      201             172
83      181             170
84      186             172
85      191             170
86      196             167
87      201             1000

isabel · 2017-03-14 05:08

Thanks Andy, I will check it as you mentioned.

isabel · 2017-03-14 05:33

Hello Andy:
I had double check the resistors which are in the same packet comes with the encoder , red black orange,
I had also tried re-run the "Test Encoder Connections" which is correct.
Then I run the code to do the calibrate, the output list as following, I don't understand.

Actually, I used to got results which are better than this time, but I didn't do the servo_set(1500) to make the servo stop at the beginning. Then I realize that I probably need to run this before I run the calibrate, then I use the screw drive to make it stop of both servo when I run the code to servo_set(1500), does this affect my servos? Does this make the calibration output are weird?
Thanks for your read. Looking forward to your reply.

=== LEFT SERVO ===

Table Entries = 67
Zero Speed Index = 1

Index Servo Drive Encoder Ticks/Second

0 0 1000
1 0 0
2 0 0
3 0 0
4 0 0
5 0 0
6 0 0
7 0 0
8 0 0
9 0 0
10 0 0
11 0 0
12 963577028 0
13 1586080 0
14 524290 0
15 111415495 0
16 661627068 0
17 637819988 0
18 661612796 0
19 571497596 0
20 1081596 0
21 -1341095684 0
22 1671420 0
23 772669440 0
24 126091264 0
25 65535 0
26 0 0
27 0 0
28 705757184 0
29 739606780 0
30 739191036 0
31 1409276 0
32 10443900 0
33 12278908 0
34 8543356 0
35 15228028 0
36 16211068 0
37 9723004 0
38 11689084 0
39 16604284 0
40 1474812 0
41 1662076 0
42 6904956 0
43 7167100 0
44 6511740 0
45 6773884 0
46 7953532 0
47 1662076 0
48 5790844 0
49 570491068 0
50 570491068 0
51 705768700 0
52 705724668 0
53 570491068 0
54 806628604 0
55 806709436 0
56 806444156 0
57 772899068 0
58 772309244 0
59 26812 0
60 1596668 0
61 570491068 0
62 805830844 0
63 570517692 0
64 571432060 0
65 -580494212 0
66 -1387963268 1000

=== RIGHT SERVO ===

Table Entries = 199
Zero Speed Index = 49

Index Servo Drive Encoder Ticks/Second

0 -195 1000
1 -193 59
2 -191 61
3 -189 63
4 -187 65
5 -185 67
6 -183 -1275068347
7 -181 865599504
8 -179 537508
9 -177 -1992327168
10 -175 569389612
11 -173 461500
12 -171 654315004
13 -169 1640508
14 -167 537135292
15 -165 537135292
16 -163 537135295
17 -161 23676
18 -159 0
19 -157 -65536
20 -155 0
21 -153 0
22 -151 0
23 -149 570491068
24 -147 704946364
25 -145 706765052
26 -143 3169340
27 -141 11885692
28 -139 14507132
29 -137 8805500
30 -135 15817852
31 -133 9395324
32 -131 9985148
33 -129 11820156
34 -127 741497980
35 -125 1662012
36 -123 6380668
37 -121 7429244
38 -119 7691388
39 -117 6642812
40 -115 8019068
41 -113 8150140
42 -111 5921916
43 -109 806444156
44 -107 772899068
45 -105 772309244
46 -103 570491068
47 -101 672214268
48 -99 672694524
49 4 806840508
50 107 26812
51 109 570491068
52 111 570491068
53 113 806825212
54 115 -1606263684
55 117 638671996
56 119 806453500
57 121 639118588
58 123 24936700
59 125 1679548
60 127 1662206
61 129 1662206
62 131 1662206
63 133 570491068
64 135 1662206
65 137 570491068
66 139 1662206
67 141 570491068
68 143 1662206
69 145 504454396
70 147 1679548
71 149 1655266557
72 151 806444156
73 153 0
74 155 0
75 157 0
76 159 0
77 161 0
78 163 0
79 165 0
80 167 0
81 169 0
82 171 0
83 173 0
84 175 0
85 177 0
86 179 0
87 181 0
88 183 0
89 185 0
90 187 0
91 189 0
92 191 0
93 193 0
94 195 0
95 197 0
96 199 0
97 99 0
98 1 0
99 3 0
100 5 0
101 7 0
102 9 0
103 11 0
104 13 0
105 15 0
106 17 0
107 19 0
108 21 0
109 23 0
110 25 0
111 27 0
112 29 0
113 31 0
114 33 0
115 35 0
116 37 0
117 39 0
118 41 0
119 43 0
120 0 0
121 0 0
122 0 0
123 199 0
124 0 0
125 67 0
126 1000 0
127 59 0
128 61 0
129 63 0
130 65 0
131 67 0
132 -1275068347 963577028
133 865599504 1586080
134 537508 524290
135 -1992327168 111415495
136 569389612 661627068
137 461500 637819988
138 654315004 661612796
139 1640508 571497596
140 537135292 1081596
141 537135292 -1341095684
142 537135295 1671420
143 23676 772669440
144 0 126091264
145 -65536 65535
146 0 0
147 0 0
148 0 705757184
149 570491068 739606780
150 704946364 739191036
151 706765052 1409276
152 3169340 10443900
153 11885692 12278908
154 14507132 8543356
155 8805500 15228028
156 15817852 16211068
157 9395324 9723004
158 9985148 11689084
159 11820156 16604284
160 741497980 1474812
161 1662012 1662076
162 6380668 6904956
163 7429244 7167100
164 7691388 6511740
165 6642812 6773884
166 8019068 7953532
167 8150140 1662076
168 5921916 5790844
169 806444156 570491068
170 772899068 570491068
171 772309244 705768700
172 570491068 705724668
173 672214268 570491068
174 672694524 806628604
175 806840508 806709436
176 26812 806444156
177 570491068 772899068
178 570491068 772309244
179 806825212 26812
180 -1606263684 1596668
181 638671996 570491068
182 806453500 805830844
183 639118588 570517692
184 24936700 571432060
185 1679548 -580494212
186 1662206 -1387963268
187 1662206 -984064900
188 1662206 638671996
189 570491068 1092124924
190 1662206 638671996
191 570491068 1226998012
192 1662206 638671996
193 570491068 1529184508
194 1662206 -1370399620
195 504454396 572039356
196 1679548 1655266428
197 1655266557 1662205
198 806444156 1000

Andy Lindsay (Parallax) · 2017-03-15 01:26

The numbers make it look like the encoder cables are not connected properly. I do not think the encoders can pass this test when the numbers look like they do. Start by going back to this page:

http://learn.parallax.com/tutorials/robot/activitybot/activitybot/navigation-basics/test-encoder-connections

The instructions tell you to use your hand to turn the wheel, and watch for a blinking light. If the P26 light does not blink while you turn the wheel with your hand, there is a problem with the encoder connection. (When you stop turning the wheel, it does not matter whether the light stays on or off. But, while you are turning the wheel with your hand, the light has to blink to prove the connection is right.)

If that test fails (no blinking), recheck your cables. Did you plug the cables into the encoders as shown here?

http://learn.parallax.com/tutorials/robot/activitybot/activitybot/mechanical-assembly/step-8-mount-left-encoder

...and here?

http://learn.parallax.com/tutorials/robot/activitybot/activitybot/mechanical-assembly/step-1-prepare-your-encoders

Did you plug the cables into the board as shown in the Plug in the Cables section on this page?

http://learn.parallax.com/tutorials/robot/activitybot/activitybot/electrical-connections

Also check the other wheel, the one that IS NOT in the picture on this page:

http://learn.parallax.com/tutorials/robot/activitybot/activitybot/navigation-basics/test-encoder-connections

When you turn that other wheel with your hand, the P27 light should blink. When you let go, it should either stay on or off.

Do not continue until the encoders pass these tests.

If you can post close-up photos of all the electrical and mechanical connections, that might also help.

Andy

isabel · 2017-03-21 04:51

I had solved this problem by re-assembled the robot again. Thanks for your help.

Activity Bot

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