New Supported Sensor Possibility? Capacitive Touch Sensor Breakout

 
#1

CAP1188 - 8-KEY CAPACITIVE TOUCH SENSOR BREAKOUT - I2C OR SPI

Hey EZ-Robot. Is this something you would consider adding to your new sensors? I know those building InMoov with V4's would love it. I am sure others would like it also.

#2

What application would you see it being used for?

#3

http://www.ez-robot.com/Community/Forum/Thread?threadId=7029

Also, bumpers, or touch like button sensors only without the tactical feel. Kind of like tv's today. They dont have buttons so much as sensors that detect which spot on the tv was touched.

They could be used for bumpers. Really anything that you want to know has made contact with something else.

My use would be to know that the hand (or what part of the hand) has touched the object I am picking up.

#4

Couldn't you do that with the ADC port? You don't need any additional hardware.

Try it - simply connect a bare wire to the adc port and let it float. Add an ADC Graph and watch what happens when you touch it.

You couldn't use it for bumpers, because objects around your home will not affect it. Think about your phone screen - what ever touches it needs to conductive

#5

The thought for bumpers was to use conductive material like copper foil which would press against another conductive material, but that too could be done with analog I suppose. I'll give it a shot. Thanks.

#6

Analog input is quite amazing! To create capacitive touch, you throw a very tiny capicator on the adc line.

Even without capacitors, you can do some pretty amazing stuff. Add the ADC Graph control and play with it Smile

#7

@DJ,

You really need to do more of those wonderful video tutorials, that inspire ideas. Not the spit polished ones, I miss the videos from your basement. EZ builder has come so far from those days and there are so many bells and whistles that I could definitely benefit from videos clips of new parts of EZ builder. Like a video library. I know you are busy running a big business, but maybe you could hand it off to one of the other fellas?! Everyone including those that are using it for STEM would benefit. I know I learn faster with videos than with written word.

#8

That device on post #1 looks good if you need a lot of input but don't want to tie up 8 ADC ports. If you're not bound by those constraints then KISS and do what DJ suggests and it will be more simple to implement.

#9

DJ (or someone who knows more electronics than me), can you explain in a little more detail how you hook this up? What does it mean to let the wire float? Are you just connecting the bare wire to the ADC signal port and nothing else? Where would the capacitor go and what do you mean by "small" (range of acceptable specs)?

Thinking about something like this on the ends of a gripper so if it grabs a person (or the cat) it wouldn't squeeze too hard.

Alan

#10

@Alan... pin "float" means that at any given time the signal pin on a port can be high or low... It floats so to speak back and forth.... You could use a pull-up resistor to keep the pin high or a pull-down resistor to keep the pin low... Both would stop the pin from "floating"... The analog port basically just measures resistance (or a voltage level between 0V - 5V)... So if you were to say touch one finger to the analog signal pin and then with another finger touch the ground on the same port you should see the value change in the analog control window... Actually haven't tried it, but that's what I am assuming will happen, anyway...

***EDIT*** Just tried it and it does drop the analog value.... interestingly enough, but not surprising the harder you squeeze the two wires between your fingers the lower the analog value goes...

So you could use this as a crude method to determine if your claw is crabbing something conductive like a cat or a human hand or even something way more conductive like metal....