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Topic: Vending machine / robot project advice (Read 3 times) previous topic - next topic

alanesq

#15
May 10, 2012, 07:45 pm Last Edit: May 15, 2012, 09:14 pm by alanesq Reason: 1
It has been  a while as I have been waiting for parts etc., but I have now made a start at building a robot.......

I have now built a basic 3 wheeled robot - at the moment there are no sensors on it so it is just obeying basic turn motor on for 3 seconds type commands
but so far so good :-)

alanesq

Been experimenting much of the weekend:

It looks like the plan to use an optical mouse is a no go - it is just not giving accurate enough data to be of any use

The ultrasound sensors are very good but I am getting a lot of places in the room where it doesn't work (I guess reflections from furniture etc.) so I can't rely on these for navigation (at least not on their own)

so any more ideas on what I can try before resorting back to the line following plan?

strykeroz


The ultrasound sensors are very good but I am getting a lot of places in the room where it doesn't work (I guess reflections from furniture etc.) so I can't rely on these for navigation (at least not on their own)
Hi, What are the ultrasonics doing that is causing you problems?
"There is no problem so bad you can't make it worse"
- retired astronaut Chris Hadfield

alanesq


Hi, What are the ultrasonics doing that is causing you problems?


It works great when pointed straight at a decent flat surface, but if I try to send the robot through a gap (e.g. out the door) or at an angle through the room etc. it soon starts receiving data of 0 or 256 which I am guessing means poor signal?


strykeroz

#19
May 13, 2012, 04:30 pm Last Edit: May 13, 2012, 04:32 pm by strykeroz Reason: 1
0 I would have thought means the pulsein() timed out without receiving an echo from your sensor, which potentially means your wall deflected the ultrasonic ping at an angle that didn't get captured by the sensor on its return...or the wall is too far away but that's unlikely from what you're saying.  Is it a HC-SR04 you're using?
"There is no problem so bad you can't make it worse"
- retired astronaut Chris Hadfield

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