Frequently Asked Questions

Version 6 (Kwabena Agyeman, 03/09/2012 10:53 pm)

1 1 Kwabena Agyeman
h1. Frequently Asked Questions
2 1 Kwabena Agyeman
3 3 Kwabena Agyeman
h3. *What is unique about CMUcam4?*
4 3 Kwabena Agyeman
5 3 Kwabena Agyeman
Traditionally fast computers are needed to capture and process camera images. It is also necessary to write the software to perform this processing. Because of this it is difficult to use vision as a sensor in simple systems.
6 3 Kwabena Agyeman
7 3 Kwabena Agyeman
The CMUcam4 vision system uses a fast low cost microcontroller to handle all of the high speed processing of the camera data and contains software to perform simple vision tasks. Because the user can choose to output only low bandwidth high level information from the vision system, like the red object is at position X-Y, it is possible for a simple processor like a Arduino or BASIC Stamp 2 microcontroller to read this data and direct a small robot in tasks like chasing a colored ball. The CMUcam4 vision system makes it possible to ignore the complexity of camera interfacing and use vision just like any other sensor (i.e. sonar) often used in robotic systems.
8 3 Kwabena Agyeman
9 3 Kwabena Agyeman
Additionally, with new TV output functionality, you can see what the CMUcam4 sees on the TV to verify that it is working!
10 3 Kwabena Agyeman
11 3 Kwabena Agyeman
h3. *What is CMUcam4's frame rate?*
12 3 Kwabena Agyeman
13 3 Kwabena Agyeman
The frame rate is 10 frames per second. This means CMUcam4 can tell you the position of an object 10 times per second. Using the serial software protocol you can slow this down if desired.
14 3 Kwabena Agyeman
15 3 Kwabena Agyeman
h3. *What baud rates does the CMUcam4 support?*
16 3 Kwabena Agyeman
17 3 Kwabena Agyeman
The CMUcam4 can communicate at any baud rate using the serial software protocol. The default power on baud rate is 19,200 bits per second.
18 3 Kwabena Agyeman
19 3 Kwabena Agyeman
h3. *How do I upgrade my CMUcam4 firmware?*
20 3 Kwabena Agyeman
21 3 Kwabena Agyeman
Please see the [[firmware]] wiki page.
22 3 Kwabena Agyeman
23 3 Kwabena Agyeman
h3. *Does CMUcam4 work outside?*
24 3 Kwabena Agyeman
25 3 Kwabena Agyeman
The CMUcam4 works outside but not in direct sunshine. It is possible to add an external filter to improve outdoor operation.
26 3 Kwabena Agyeman
27 3 Kwabena Agyeman
h3. *Can I write custom code for CMUcam4?*
28 3 Kwabena Agyeman
29 3 Kwabena Agyeman
Please see the [[firmware]] wiki page.
30 3 Kwabena Agyeman
31 3 Kwabena Agyeman
h3. *How much power does CMUcam4 consume?*
32 3 Kwabena Agyeman
33 6 Kwabena Agyeman
The complete system consumes about 200 milliamperes.
34 3 Kwabena Agyeman
35 3 Kwabena Agyeman
h3. *What is the camera's field of view?*
36 3 Kwabena Agyeman
37 3 Kwabena Agyeman
About a 25 degree field of view, which is relatively narrow.
38 3 Kwabena Agyeman
39 3 Kwabena Agyeman
h3. *What processor does CMUcam4 use?*
40 3 Kwabena Agyeman
41 3 Kwabena Agyeman
Please see the [[firmware]] wiki page.
42 3 Kwabena Agyeman
43 3 Kwabena Agyeman
h3. *What CMOS camera does CMUcam4 use?*
44 3 Kwabena Agyeman
45 3 Kwabena Agyeman
Please see the [[firmware]] wiki page.
46 3 Kwabena Agyeman
47 3 Kwabena Agyeman
h3. *Does CMUcam4 work with other CMOS cameras?*
48 3 Kwabena Agyeman
49 5 Kwabena Agyeman
No. Currently the hardware and software system have been designed to work specifically with the "OmniVision":http://www.ovt.com/ "OV9665":http://www.ovt.com/products/sensor.php?id=5 CMOS camera. The system would need to be completely redesigned to work with another camera.
50 3 Kwabena Agyeman
51 3 Kwabena Agyeman
h3. *Is there some place I can find answers to additional questions I have?*
52 3 Kwabena Agyeman
53 3 Kwabena Agyeman
Yes. Please visit the forums "here":http://cmucam.org/projects/cmucam4/boards.
54 3 Kwabena Agyeman
55 3 Kwabena Agyeman
h3. *Where can I find out more about computer vision in general?*
56 3 Kwabena Agyeman
57 3 Kwabena Agyeman
The CMUcam4 performs the simple computer vision task it was designed to perform in a small, inexpensive package. However, the general computer vision problem of trying to recognize arbitrary objects under arbitrary conditions is still a very active research topic and very far from being anywhere near a solved problem.
58 3 Kwabena Agyeman
 
59 3 Kwabena Agyeman
If you want to learn more about computer vision, you might want to try these links: 
60 3 Kwabena Agyeman
61 4 Kwabena Agyeman
* "The On-Line Compendium of Computer Vision":http://www.dai.ed.ac.uk/CVonline/ 
62 4 Kwabena Agyeman
* "The Computer Vision Home Page at CMU":http://www.cs.cmu.edu/~cil/vision.html