Rope vibration/touch sensor

I need your help.

I need to find a way to sense wether a tense rope is being touched or not. Another way it should work is measuring if the rope is vibrating.

I don't have limitations on the rope material (if it's the best solution, I can use conductive material). The ropes should be really big and strong (diameter like climbing ropes, about 4 meters long).

Can you please suggest which is the best way to do this? Should piezo work?

Thank you, any help will be really appreciated. :confused:

Filippo

filipporox:
I need your help.

I need to find a way to sense wether a tense rope is being touched or not. Another way it should work is measuring if the rope is vibrating.

I don't have limitations on the rope material (if it's the best solution, I can use conductive material). The ropes should be really big and strong (diameter like climbing ropes, about 4 meters long).

Can you please suggest which is the best way to do this? Should piezo work?

Thank you, any help will be really appreciated. :confused:

Filippo

can you attach an accelerometer? the ADXL345 is a very common sensor. Here is a link to the data sheet
ADXL345 I2C Accelerometer

Chuck.

Hi,

Depending on the kind of vibrations you want to measure a simple MEMS accelerometers should work. Those have been used to monitor wind-induced oscillations of strands form suspension bridges. For those cases +- 12 g were sufficient, however, for a polymer rope the situation may be different.

Kind regards
John

Following on the comments already made, I can confirm that the ADXL345 is very sensitive to vibrations. I use the tap sensing feature to trigger interrupt alarms when a water droplet impacts on an abs housing, and I usually have to add significant time delays afterwards to prevent the unit from echo triggering when it is set to high sensitivity. They can even react to loud noises.

I posted the drip sensor code on the projects github.

Dig into the initADXL345() function to see how I set up the registers to generate the "single tap" interrupts for this.