Robot Control via Ethernet Shield

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morana_pavicic
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Joined: Wed Aug 22, 2018 5:31 am

Robot Control via Ethernet Shield

Post by morana_pavicic » Wed Aug 22, 2018 5:38 am

Hi guys! :)

I'm working on a sensor system which should enable a robot arm to react as human activates a certain sensor.

So, what I have available is:

Capacitive sensor from Sparkfun: https://www.sparkfun.com/products/retired/9695
Proximity sensor from Adafruit: https://www.adafruit.com/product/466
Arduino UNO
Arduino ETHERNET SHIELD 2
Universal Robot UR5

So far my reach is connecting sensors to Arduino (I know, not much... I'm pretty new in all of this). The idea is to manipulate the robot by human hand, e.g. by touching conductive textile connected to MPR121 and mounted on the robot, it should stop/change direction, and by approaching with a hand to VCNL4010, it should slow down if in motion. The initial idea was to make it look like some sort of skin cell, but for now I would like to put these two sensors to work, and upgrade it step by step.

I'm aware of all the working principles of the Ethernet, but never actually dealt with it, or with Arduino contolled robot. So I'm wondering if anybody has some examples of similar projects or if anybody worked on something like that (Internet is full of everything, but when you need something specifically, it's a blank page). At this moment I'm desperate because all my work comes down to brainstorming and wasting time.

What I made is the first version of a "skin cell". Also, I have a problem with wires, not sure if i can connect multiple short wires to make a longer one since the proximity sensor should be on a robot arm with the conductive textile and Arduino itself somewhere around the base of the robot. I know resistance increases, and as a result, current decreases. I don't know if I'm talking nonsense rn, but most of my knowledge is unfortunatelly theoretical.

Thank you advance! :)

Valen
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Joined: Wed Dec 22, 2010 2:05 am

Re: Robot Control via Ethernet Shield

Post by Valen » Sat Sep 15, 2018 6:36 am

A meter/yard (I am guessing as the norm of length used) of normal conductive copper wire will not cause significant resistance problems for carrying signals. Power wires would need thicker wires but that too should not be a problem until it goes into multiple amps. Care must be taken they have sufficient room to flex around joints or breaks are to be expected in the long run. Depending on the sensitivity of signals they could also become great antennas inducing noise. Anyway, I get the impression you intend to use conducive thread/fabric for transmitting signals/power to it. That probably will have higher resistances. Not sure that is the appropriate way. Using conductive fabric as sort of switches in local places could be appropriate but for getting the signal to the microcontroller/Arduino I would do with normal (isolated) wire.

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