# Documentation and Examples

**URL:** <https://forums.openmv.io/t/documentation-and-examples/121>\
**Category:** OpenMV Boards\
**Created:** [September 3, 2016, 11:20am UTC](https://forums.openmv.io/t/documentation-and-examples/121 "2016-09-03T11:20:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![bob63](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@bob63](https://forums.openmv.io/u/bob63)\
**Post date:** [September 3, 2016, 11:20am UTC](https://forums.openmv.io/t/documentation-and-examples/121/1 "2016-09-03T11:20:34Z")

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Hi,  
I’ve received my board few day afo , but was not working because probably the firmware was not flashed in. Thansk to a post in the forum I’ve fixed the issue and at the moment I’ve installed the release 1.5 .  
Now I’ve started to play with the board using the exmples that I’ve have updated taking the ones from Github repository.  
I’ve some difficulties with the optical\_flow 2.py because when it run I got this error message but I don’t find in the documentation something about img.find\_displacement:  
Am I wrong to use the documentation or there is another place where find some updates on the doc ?  
Is there any way to have the documentation printable in as PDF file ?

Thanks. Robero.

 ![Cattura.JPG](https://canada1.discourse-cdn.com/flex029/uploads/openmv1/original/1X/48b44a096cb5a7269b25430d06d40ad9b523f551.jpeg)

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**Author:** ![bob63](https://avatars.discourse-cdn.com/v4/letter/b/e274bd/32.png) [@bob63](https://forums.openmv.io/u/bob63)\
**Post date:** [September 3, 2016, 11:47am UTC](https://forums.openmv.io/t/documentation-and-examples/121/2 "2016-09-03T11:47:55Z")

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After my post I’ve tried to update Firmware version to 1.8 but it doesent work and the board isn’t recognised by my PV ( W7 ). Why ?  
Updating at version I.7 the optical\_flow don’t show the above error , so I suppose was a problem of firmware .  
Still open the question on the documentation.  
Than. Roberto.

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**Author:** ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)\
**Post date:** [September 3, 2016, 12:37pm UTC](https://forums.openmv.io/t/documentation-and-examples/121/3 "2016-09-03T12:37:13Z")

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Hi, did you use the new GUI? Please see the downloads page on the the OpenMV website. As for documentation on that function I don’t have then time to finish it and the IDE. So, I will focus on the IDE first for now. As for how that function works. You just need to compare a copy if the old image returned from snapshot with a new image. If you update the old image every time in the loop then you just get a delta function displacement output. If you only create the old image copy once and then update the new image in the loop you get a global displacement. Nite that phase correlation only works for small displacements because the result is bad. The function outputs a confidence value which tells you when the result is bad.

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**Author:** ![kwagyeman](https://yyz1.discourse-cdn.com/flex029/user_avatar/forums.openmv.io/kwagyeman/32/4_2.png) [@kwagyeman](https://forums.openmv.io/u/kwagyeman)\
**Post date:** [September 3, 2016, 12:38pm UTC](https://forums.openmv.io/t/documentation-and-examples/121/4 "2016-09-03T12:38:44Z")

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I’m running this company in my free time after my day job. So, it’s kinda triage at this point on what to work on. Sorry about that.