ActivityBot Robot- Issues

ASHEN · 2014-04-16 16:23

I am student and working on the activitybot. I managed to assemble the robot and also finished writing the code. The robot was working fine. The next day when I started to work on the robot it was not performing the actions as per the code. I re calibrated and downloaded the test code and I am having issues. The robot goes forward but does and then just goes in circle and stops.

I checked the batteries, the servo connections and they are okay. This is the first time I am working on the activity bot. Please let me know what I may be doing wrong.

Thanks for your help.

GordonMcComb · 2014-04-16 18:34

How exactly did you check the batteries? It sounds like maybe the switch on the board was still on and the batteries got drained. If left connected servos will slowly drain out batteries, even if everything else is off.

Batteries can be tested using a battery tester (places the battery under load) or by swapping out with a brand new set. Its not enough to test batteries with a volt meter and no load.

ASHEN · 2014-04-16 19:00

I have removed the batteries and replaced them with new ones. I just finished recalibrating and ran the program called open test for trim. It was supposed to go forward 80 cm instead it went in reverse about 10ft and stopped.

I checked the servo connections.

Thanks

Mike G · 2014-04-17 04:08

Check all your connections - encoders too.

Welcome to the forums

ASHEN · 2014-04-17 07:37

I did check all connections. Ran test to check if encoder is working but still have the same issue. If I change the values to negative then it moves forward. Do you think there is something wrong in the board as it does not interpret the code as it should .

Mike G · 2014-04-17 07:58

Do you think there is something wrong in the board as it does not interpret the code as it should .

Yes, I think you have one of those mirror image boards... you should swap the Left/Right encoders and/or servo connections.

Chris Savage · 2014-04-17 13:39

Try this section in http://learn.parallax.com/activitybot/calibrate-your-activitybot and post the output. An example of a healthy calibration is below. Of course, if on inspection, it's obviously not following the pattern here, you should re-run the calibration, making sure to wait until the yellow lights turn off. Also, power jumper for P12 and P13 should be at VIN, and batteries should be fresh, hopefully in the 7 to 8 V range.

[/FONT]=== LEFT SERVO ===

Table Entries = 89
Zero Speed Index = 41


Index   Servo Drive     Encoder Ticks/Second
-----   -----------     --------------------
0       -194            1000
1       -189            170
2       -184            170
3       -179            170
4       -174            188
5       -169            181
6       -164            172
7       -159            170
8       -154            172
9       -149            168
10      -144            172
11      -139            172
12      -134            170
13      -129            168
14      -124            159
15      -119            164
16      -114            162
17      -109            159
18      -104            154
19      -99             150
20      -94             146
21      -89             145
22      -84             139
23      -79             132
24      -74             130
25      -69             124
26      -64             115
27      -59             106
28      -54             97
29      -49             89
30      -44             82
31      -39             71
32      -34             65
33      -29             56
34      -24             45
35      -19             36
36      -14             27
37      -9              19
38      -7              14
39      -5              10
40      -3              6
41      4               0
42      11              2
43      13              8
44      15              11
45      17              14
46      19              16
47      21              22
48      26              33
49      31              43
50      36              50
51      41              59
52      46              67
53      51              80
54      56              86
55      61              93
56      66              98
57      71              109
58      76              113
59      81              122
60      86              125
61      91              135
62      96              140
63      101             143
64      106             149
65      111             150
66      116             149
67      121             162
68      126             153
69      131             157
70      136             159
71      141             164
72      146             160
73      151             162
74      156             168
75      161             170
76      166             164
77      171             176
78      176             164
79      181             168
80      186             168
81      191             172
82      196             170
83      201             170
84      181             168
85      186             168
86      191             172
87      196             170
88      201             1000




=== RIGHT SERVO ===


Table Entries = 89
Zero Speed Index = 40


Index   Servo Drive     Encoder Ticks/Second
-----   -----------     --------------------
0       -195            1000
1       -190            174
2       -185            170
3       -180            176
4       -175            172
5       -170            172
6       -165            170
7       -160            172
8       -155            174
9       -150            170
10      -145            166
11      -140            166
12      -135            166
13      -130            163
14      -125            159
15      -120            157
16      -115            148
17      -110            154
18      -105            156
19      -100            145
20      -95             142
21      -90             140
22      -85             133
23      -80             121
24      -75             121
25      -70             110
26      -65             104
27      -60             97
28      -55             88
29      -50             80
30      -45             72
31      -40             68
32      -35             56
33      -30             45
34      -25             37
35      -20             28
36      -15             19
37      -13             19
38      -11             11
39      -9              8
40      -1              0
41      7               6
42      9               7
43      11              14
44      13              14
45      15              21
46      20              31
47      25              41
48      30              45
49      35              58
50      40              66
51      45              76
52      50              82
53      55              91
54      60              99
55      65              105
56      70              114
57      75              120
58      80              121
59      85              134
60      90              137
61      95              140
62      100             148
63      105             157
64      110             156
65      115             159
66      120             172
67      125             164
68      130             168
69      135             174
70      140             164
71      145             168
72      150             166
73      155             170
74      160             170
75      165             172
76      170             170
77      175             172
78      180             172
79      185             176
80      190             176
81      195             166
82      200             168
83      175             172
84      180             172
85      185             176
86      190             176
87      195             166

88      200             1000[FONT=arial]

Phil Pilgrim (PhiPi) · 2014-04-17 13:55

Make sure you have the 10K pullups on the servo outputs. Trim the resistor leads short, so the resistors don't flop around and touch each other's leads or pull out of their receptacle holes. This was an issue with my students, who had problems like yours, until we got everythig trimmed and snug.

-Phil

Andy Lindsay (Parallax) · 2014-04-17 14:09

Hi folks, this thread is being relocated to the Learn forum.

Andy

Andy Lindsay (Parallax) · 2014-04-17 14:11

"Make sure you have the 10K pullups on the servo outputs...."

Not sure what this is for, the Activity Board already has series resistors built in between servo port signal and I/O pin, so we don't add any resistors to the servos. The encoders do require 20 k pull-up resistors (red-black-orange), which is in the assembly instructions.

Phil Pilgrim (PhiPi) · 2014-04-17 14:19

Andy,

I don't think the resistor value is critical. I and all my students are using 10K, and they work just fine. I guess it's the series resistors that make the 20K preferable, though.

-Phil

Chris Savage · 2014-04-18 08:42

By the way, the link I posted includes a troubleshooting guide. Have you tried the items listed there? http://learn.parallax.com/activitybot/troubleshooting

ASHEN · 2014-04-18 11:59

Hi Andy,

based on the suggestion from Chris i checked the calibration. Here are the values for the the test. They seem to be correct. When I run the "test for trim"code the robot goes backward and travels 10feet .
As per the code it should go 80 cm and forward. Below is the code used.

/*
Test for Trim.c

Test and adjust trim for servos and encoders

http://learn.parallax.com/activitybot

*/

#include "simpletools.h"
#include "abdrive.h"

int main()
{
drive_trimSet(0, 0, 0);
drive_speed(32, 32);
pause(8000);
drive_speed(0, 0);
}

Calibration out put:
=== LEFT SERVO ===

Table Entries = 88
Zero Speed Index = 41

Index Servo Drive Encoder Ticks/Second

0 -194 1000
1 -189 172
2 -184 176
3 -179 174
4 -174 170
5 -169 176
6 -164 174
7 -159 172
8 -154 170
9 -149 178
10 -144 174
11 -139 163
12 -134 172
13 -129 172
14 -124 165
15 -119 158
16 -114 160
17 -109 160
18 -104 163
19 -99 154
20 -94 152
21 -89 147
22 -84 146
23 -79 143
24 -74 136
25 -69 131
26 -64 122
27 -59 113
28 -54 107
29 -49 101
30 -44 92
31 -39 84
32 -34 75
33 -29 66
34 -24 59
35 -19 49
36 -14 39
37 -9 29
38 -4 20
39 1 10
40 3 6
41 11 0
42 19 8
43 21 11
44 23 14
45 25 18
46 27 21
47 32 31
48 37 41
49 42 51
50 47 58
51 52 67
52 57 76
53 62 86
54 67 94
55 72 100
56 77 110
57 82 112
58 87 123
59 92 123
60 97 134
61 102 138
62 107 144
63 112 148
64 117 149
65 122 155
66 127 158
67 132 155
68 137 167
69 142 160
70 147 164
71 152 164
72 157 165
73 162 167
74 167 167
75 172 170
76 177 170
77 182 174
78 187 171
79 192 172
80 197 172
81 202 169
82 177 170
83 182 174
84 187 171
85 192 172
86 197 172
87 202 1000

=== RIGHT SERVO ===

Table Entries = 89
Zero Speed Index = 40

Index Servo Drive Encoder Ticks/Second

0 -195 1000
1 -190 163
2 -185 178
3 -180 174
4 -175 170
5 -170 167
6 -165 167
7 -160 174
8 -155 162
9 -150 170
10 -145 172
11 -140 158
12 -135 158
13 -130 158
14 -125 158
15 -120 152
16 -115 146
17 -110 141
18 -105 145
19 -100 136
20 -95 139
21 -90 127
22 -85 117
23 -80 115
24 -75 102
25 -70 98
26 -65 91
27 -60 79
28 -55 75
29 -50 65
30 -45 55
31 -40 44
32 -35 36
33 -30 28
34 -25 19
35 -23 18
36 -21 15
37 -19 10
38 -17 6
39 -15 5
40 -9 0
41 -3 5
42 -1 10
43 1 15
44 3 18
45 5 21
46 10 31
47 15 40
48 20 50
49 25 58
50 30 69
51 35 74
52 40 85
53 45 93
54 50 100
55 55 112
56 60 113
57 65 117
58 70 123
59 75 131
60 80 134
61 85 144
62 90 142
63 95 150
64 100 152
65 105 158
66 110 158
67 115 155
68 120 163
69 125 160
70 130 165
71 135 165
72 140 170
73 145 165
74 150 170
75 155 166
76 160 166
77 165 168
78 170 168
79 175 170
80 180 168
81 185 166
82 190 166
83 195 167
84 200 167
85 185 166
86 190 166
87 195 167
88 200 1000

ASHEN · 2014-04-18 12:11

In the "test for trim" code i changed the drive speed values from positive 32 to negative 32 and the robot went forward. However it still does not travel 80cm but i does run for 8 sec.

Chris Savage · 2014-04-18 12:32

Please stand by...we're trying to come up with a reason why this may be happening.

Chris Savage · 2014-04-18 13:09

Just to confirm, you're downloading the calibration code to EEPROM and not to RAM, correct? Also, are you sure the left/right servos and encoders are plugged into the correct headers on the board?

ASHEN · 2014-04-18 13:25

When I download the calibration code I do it to EEPROM and also I checked that my left and right servos and left and right encoders are in the right pins. Left servo: P12, Right servo P13, Left encoder: P14, Right encoder P15.

ASHEN · 2014-04-18 13:45

I am trying different ways to get the robot working. I wrote the following code. It complied correctly but when the robot runs it does not read the second bunch of code. So the robot goes in a circle for 3 seconds but instead of going straight it continues going in a circle.

#include "simpletools.h" // Include simple tools #include "abdrive.h"
int main() // Main function
{

drive_trimSet(0, 0, 0);
drive_speed( 32 , -32 );

pause(3000);

drive_speed(0, 0);

drive_speed(32, 32);
pause(3000);

drive_speed(0, 0);

}

ASHEN · 2014-04-18 14:37

Chris,

Do you think we will have a resolution today.

Chris Savage · 2014-04-18 14:41

I am working to get you answers as quick as possible. Just out of curiosity, you have adjusted the potentiometers on the servos, have you?

ASHEN · 2014-04-18 14:45

No i have not. Can you explain how I could do that.

ASHEN · 2014-04-18 15:23

Chris could you give me the code needed to make my robot travel straight for 5 sec and then execute a 90-degree right turn and then go straight for another 5 sec.

ASHEN · 2014-04-19 10:31

Chris,

I have still got no solutions to why the robot is doing what it is doing. I am running out of time to get my class project done.

Thanks

sunil

Mike G · 2014-04-19 14:35

The code example posted in #18, has #include "abdrive.h", commented. Place #include "abdrive.h" on the next line under #include "simpletools.h".

#include "simpletools.h"
#include "abdrive.h"

int main()                   
{
  drive_trimSet(0, 0, 0);
  drive_speed(32, 32);
  pause(8000);
  drive_speed(0, 0);
}

Run the test code with the robot on block so the wheels do NOT touch the ground. Do both wheels turn?

ASHEN · 2014-04-21 07:52

Thanks for the suggestion mike. The wheels turn but the problem still exists as mentioned in #18

Chris Savage · 2014-04-21 09:49

The code you asked for is code you already have. What I could send you is an exact copy of what you have. Unfortunately I can't see the robot to verify the connections. I'm still wondering if the encoders are connected backward, but cannot verify this.

ASHEN · 2014-04-21 09:57

Checked the encoders . They are connected properly.

I still think there is some issue with board.

Phil Pilgrim (PhiPi) · 2014-04-21 10:35

I'm not sure I get the call to drive_trimSet. Here's its description:

/**
* @brief Stores trim values to EEPROM.
*
* @details Trim values can compensate for mechanical wheel alignment errors.
* When you set the ActivityBot's trim, you are telling it to make a certain
* wheel turn an extra tick per certain number of ticks. For example, you
* can use this to make the right wheel turn 1 extra tick per every 64 ticks.
* It will actually just expect to see an encoder transition 1/64th of a tick
* sooner with every tick.
*
* @param direction Selects to set the trim for a given direction. Use
* AB_FORWARD OR AB_BACKWARD.
*
* @param side Selects the side to make one more or less ticks per number of
* ticks. Use AB_LEFT or AB_RIGHT to select the left or right wheel.
*
* @param value Number of ticks that should elapse before the extra tick will
* have accumulated. Use a negative number if you want a given wheel to go
* one less tick per number of ticks instead of one more tick.
*/
void drive_trimSet(int direction, int side, int value);

The problem is the zero parameters. They don't correspond to either the direction or side arguments, which are spec'd to be either -1 or 1. So what does the call with zero parameters accomplish, if anything? I'd leave it out entirely. I know I've never used it.

Also, I still suspect that you've reversed the servo connections and the encoder connections. Just to be sure, is this the way you've hooked things up?

attachment.php?attachmentid=108248&d=1398101939

attachment.php?attachmentid=108248&d=1398101939

In any event, I do not believe the Activity Board is defective. It's got to be something else.

-Phil

Andy Lindsay (Parallax) · 2014-04-21 10:40

ASHEN, I sent you a PM to set up a telephone meeting. Please check your private message inbox.

Thanks, Andy

Chris Savage · 2014-04-21 11:06

I also requested this information via e-mail.

Andy Lindsay (Parallax) · 2014-04-21 13:59

Check if the shunt jumper that sets P14 and P15 to 5 V is fitting tightly over the pins. It's the little removable piece on the lower two of three pins between the P13 and P14 servo ports.

I found a loose one, and was able to duplicated all your symptoms. Then, I pressed it lightly toward the P13 servo with a fingernail to complete the circuit, and the program started working correctly.

FIX

- DISCONNECT POWER AND USB CABLEs

- Remove the shunt jumper that connects the 5V and center pins. (From the 3-pin power header between the P13 and P14 ports).

- Bend the lower pin toward its 5 V label and the center pin toward the VIN label. (Just bend them away from each other very slightly, we only need to bend them far enough to make the shunt jumper fit more tightly.)

- Replace the shunt jumper that connects the 5V and center pins.

- Reconnect power and USB cables

- Retry your test code.

ActivityBot Robot- Issues

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