Use of Malloc

[mjs513]

Hi Carlos

Thanks for your work. Easiest to understand implementation of VFH that I have seen. Now to the question. Prior to your changes I had this almost working on a Teensy 3.1 or Due board. Ran into a couple of issues one of which was I was not sure what the output was suppose to look like and second is there a way of not using malloc in the implementation. I am not a C programmer, learning by trial and error here. So I would appreciate any help you could avoid to give me here with an example output and what I could do with malloc.

thanks
Mike

PS. Can't wait to see what you do with VFH+ and VFH*

[agarie]

Hey @mjs513, thanks for posting this issue (and for the 'easiest to understand implementation' part!) and I'm sorry for the late response. I'm a bit overwhelmed at work right now.

What problems are you having right now? How are you trying to compile the code? :)

[mjs513]

Hi Carlos
Sorry for the delay in responding but things are pretty busy around here as well. Anyway back to problem at hand. I did a little more experimenting and think the issue that there is just not enough memory on the Arduino Mega. I ran several cases and it would always return 90 deg or just hang. I then loaded it on a Arduino Due and it ran ok but am getting some strange results:

setting up grid
Finished setting up grid
Measures
0, 2, 187
1, 28, 180
2, 78, 21
3, 35, 187
4, 126, 10
5, 92, 266
6, 32, 345
7, 3, 313
8, 106, 18
9, 19, 72
10, 26, 255
11, 59, 133
12, 71, 187
13, 107, 331
14, 61, 320
15, 45, 262
16, 85, 54
17, 2, 284
18, 74, 162
19, 35, 0
20, 114, 345
21, 91, 100
22, 0, 3
23, 71, 244
24, 46, 309
25, 53, 201
26, 50, 64
27, 87, 104
28, 113, 61
29, 105, 3
30, 70, 18
31, 23, 39
32, 20, 241
33, 33, 273
34, 35, 82
35, 50, 219
36, 102, 277
37, 96, 111
38, 63, 201
39, 106, 320
40, 107, 248
41, 31, 219
42, 98, 320
43, 79, 270
44, 20, 187
45, 71, 205
46, 91, 72
47, 79, 18
48, 36, 309
49, 15, 172

Position of the robot: (%d, %d)
26, 26

Updating the certainty grid...

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---------------------x-----------------------------ddddd
----------------------x-x-x-x----------------------ddddd
--------------------xo--------xx-------------------ddddd
-------------------xx-x--------x--x----------------ddddd
-------------------x------x-x---x------------------ddddd
-----------------x-xx--x-xxxxx--x------------------ddddd
---------------xxx-xxxxxx--xox------x--------------ddddd
-------------------xx-xoxxo-x--x---x---------------ddddd
-------------------x--xxxxxx-o-x-xxx---------------ddddd
---------------x--x--xxooxoo--x-xx---x-------------ddddd
---------------------xxooooooxx--x---x-------------ddddd
---------------xxx--xxxoooooox--x------------------ddddd
------------------xx--xxooooooo-x-x----------------ddddd
---------------x----x-xxooooox---------------------ddddd
--------------x----x-x-ooxoxooo-x-x----------------ddddd
---------------x-x--o-oxx-oxx--xxx---x-------------ddddd
-------------------xx--x--x-o-xxxx-----------------ddddd
----------------x----xx-x-x---x-x-xx---------------ddddd
---------------x--x---ox--x-o----x-----------------ddddd
-------------------x---xx-------x--x---------------ddddd
---------------------x-x-------xx------------------ddddd
--------------------x--x---x--x--------------------ddddd
--------------------x------x-x---------------------ddddd
----------------------xx------x--------------------ddddd
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-oo-oo--ooo----------------------------------------ddddd
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Updating the polar histogram...

Next direction: %d [degrees]
165799
0

You don't by any chance have a routine that you print out the histograms do you? Any suggestions?

Thanks
Mike