# Where do i find constants and functions

**URL:** <https://forum.sunfounder.com/t/where-do-i-find-constants-and-functions/167>\
**Category:** Robotic kit for Raspberry Pi\
**Created:** [March 12, 2023, 9:16pm UTC](https://forum.sunfounder.com/t/where-do-i-find-constants-and-functions/167 "2023-03-12T21:16:46Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![bosshmic](https://avatars.discourse-cdn.com/v4/letter/b/e480ec/32.png) [@bosshmic](https://forum.sunfounder.com/u/bosshmic)\
**Post date:** [March 12, 2023, 9:16pm UTC](https://forum.sunfounder.com/t/where-do-i-find-constants-and-functions/167/1 "2023-03-12T21:16:46Z")

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finaly made it up to the point where i run obstacle avoidance.  
while i am able to aceess ultra\_sonic\_avoid.py and i do understand the flow of the programming as described in the manual i am not clear where i would find functions and parameters in order to edit, such as:

- back\_distance
- fw.turn(angle)  
so i am curious on hwo to access edit those using putty.  
thanks

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**Author:** ![SunFounder\_Moderator](https://avatars.discourse-cdn.com/v4/letter/s/34f0e0/32.png) [@SunFounder\_Moderator](https://forum.sunfounder.com/u/SunFounder_Moderator)\
**Post date:** [March 13, 2023, 8:14am UTC](https://forum.sunfounder.com/t/where-do-i-find-constants-and-functions/167/2 "2023-03-13T08:14:13Z")

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Sorry, I don’t understand which product you are talking about. Could you please describe in detail what product it is, what difficulties you have encountered, and what problems you need to know about?

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**Author:** ![bosshmic](https://avatars.discourse-cdn.com/v4/letter/b/e480ec/32.png) [@bosshmic](https://forum.sunfounder.com/u/bosshmic)\
**Post date:** [March 13, 2023, 4:42pm UTC](https://forum.sunfounder.com/t/where-do-i-find-constants-and-functions/167/3 "2023-03-13T16:42:15Z")

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Hy  
talking about picar-s.  
the manual , after installation of the ultrasonic sensor describes the code of “ultra\_sonic\_avoid.py”  
(e.g. page 49, [https://docs.sunfounder.com/\_/downloads/picar-s/en/latest/pdf/](https://docs.sunfounder.com/_/downloads/picar-s/en/latest/pdf/)).  
under page 52 of the same it describes some functions and parameters (in bold). But i did not understand on where i would find and or create/modify those and how to access them.

hope this clarifies. its not about the hardware its about orienation within the files on the raspery pi itself.  
KR

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<div class="post-metadata">

**Author:** ![SunFounder\_Moderator](https://avatars.discourse-cdn.com/v4/letter/s/34f0e0/32.png) [@SunFounder\_Moderator](https://forum.sunfounder.com/u/SunFounder_Moderator)\
**Post date:** [March 14, 2023, 4:08am UTC](https://forum.sunfounder.com/t/where-do-i-find-constants-and-functions/167/4 "2023-03-14T04:08:05Z")

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> <https://github.com/sunfounder/SunFounder_PiCar-S/blob/V3.0/example/ultra_sonic_avoid.py>

If you want to modify the code, you can only use it in pi modifications.

 ![C3CC1F98-F531-43ad-A6EB-A7384335C5DF](https://canada1.discourse-cdn.com/flex029/uploads/sunfounder/original/1X/50918a2ccec978c94f8e8e6738bf534e0623a1d3.png)