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Topic: Robotic Controls (Read 1 time) previous topic - next topic

jagatia

Hey there, im working on a simple robot using servos and flex sensors for human control...

Problem is, i have no idea where to buy flex sensors from the UK?

keeper63


Hey there, im working on a simple robot using servos and flex sensors for human control...

Problem is, i have no idea where to buy flex sensors from the UK?


Having problems using Google, I see...

http://robosavvy.com/store/product_info.php/products_id/415

Another option might be to make your own, using homemade conductive glue:

http://www.instructables.com/id/Make-Conductive-Glue-and-Glue-a-Circuit/ (also be sure to check out his referenced web site)

Finally - something you might try is building an optical bend sensor:

1) Buy some shiny aquarium tubing, some black heat-shrink tubing to fit over the aquarium tubing, plus a red or green LED and an LDR (the LED and LDR should be able to fit inside the aquarium tubing snugly).
2) Fit the heatshrink over a length of tubing (a bit longer than your finger, or whatever you need for the bend sensor) - it should also be a snug fit; if it is slightly loose, use a heat gun on low to shrink it up.
3) Fit the LED on one end of the tubing, and the LDR on the other end. You may need to use some super-glue or epoxy (or even hot glue in a pinch, but it won't be as secure).

Once you have it assembled, you'll want to hook up the LED so that it turns on (use a 3-6 VDC battery and a series resistor inline with the LED to limit current - consult your datasheet for the LED to figure out what the maximum current it can sink before failure, then run about 10-20 percent under this). The LDR you'll want to hook up to the Arduino like in these tutorials:

http://www.ladyada.net/learn/sensors/cds.html
http://www.arduino.cc/playground/CourseWare/AnalogInput
http://little-scale.blogspot.com/2007/11/connecting-ldr-to-arduino.html

(I can't vouch for any of these tutorials - caveat emptor)

Basically, you monitor your analog port, and when the tubing is bent, less light is "seen" by the LDR from the LED, and the value changes. A red or green LED is used because 1) LDRs are more sensitive to the red/green portion of the spectrum (if you have a datasheet for your LDR, you might check it), and 2) They tend to be inexpensive.

Hope this helps.

:)
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

jagatia

Thanks mate, its very expensive for flex sensors.

keeper63


Thanks mate, its very expensive for flex sensors.


Another source for flex sensors - if you can still find them - are old Mattel Nintendo PowerGloves; there are four sensors per glove (the pinkie finger wasn't sensed). PowerGloves are getting more difficult to find, but they can still be had - although they are become collector items, and the price is increasing (but per sensor, it might be worth it - plus you'd get a set of ultrasonic transmitters and receivers for other experiments, I suppose).

:)
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

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