GoPiGo Servo Zero


#1

I ran servo(0) in Python and the servo points as shown in the attachment. I am assuming it should point to the right of the robot, bot it is off by maybe 30 degrees. When I do servo(180) it tries to go past its maximum and hits the chassis. When I run the servo test using basic_servo.py and use option s: move servo home, it does not point straight ahead, but points a little to the left. It looks like there is a zeroing problem. How do I fix this? Thanks!!!


#2

I mounted the servo on the canopy and did some mechanical adjustments. I think its as good as it will get now. Since I know the limitations, I can programmatically compensate for this. Thanks!!!


#3

Just to followup, glad you solved the problem. You need to set the GoPiGo white plastic lip so that it’s 90 degrees from the GoPiGo. There’s a step in there I think we might be missing in our instructions, basically you need to find out where 90 degrees are and tighten up around it.


#4

Thanks. I think the only remaining issue is that the servo motor has a toothed wheel that can attach to the white plastic thing in steps. So it cannot point straight ahead as its off by a few degrees. It was off by around 30 degrees initially, but I fixed that problem. I can program a workaround for this.


#5

No problem. We will work to put some better directions up, I can see how this step could be confusing.

Tell me a little more about the tooth wheel issue. Can you back the screw out, adjust the initial starting point so that it zeros out? Or are you saying the teeth on the toothed wheel are too rough to be precise?


#6

I tried this. Its either pointing a little to the right or a little to the left. Since this has a toothed wheel, there can’t be any finer adjustment. Yes the toothed wheel is too rough to be precise. However since I plan to write my own program to make this move around, I can easily compensate. Thanks!!!


#7

Guys, I know it is an old issue, but I have exactly the same issue. I think it is more of a calibraion on the servo module. I tried mechanically to adapt, but basically to me 100 fits the 90… Now the question is how can I tell the bot to adjust to that?