Ping from one device to another.

Using Arduino Sensors
#1

I would like to use a ping from one device to another at a specific frequency (so that multiple devices can be in the same vicinity and paired).

My idea is the initial ping causes the second device to ping back, giving a time lapse (i.e. distance).

The trick is, I don’t know where the devices are relative to each other, so I can’t just use an SRF05 or similar, I just need to know the distance between them (direction is another issue).

Is there an Ultrasonic sender module and separate receiver module that is frequency controllable and Omni-directional?

The purpose of this is to keep one device at a fixed distance from the other as a pair. One device is the master, the other a slave that will move to keep the distance between them fixed.

Any other methods or ideas would be appreciated.

Thanks in advance for any help.

#2

Why not simply fit ultrasonic module to one section and make it keep fixed distance from other?

Weedpharma

#3

The problem is I don't know the direction to look. Could be anywhere: up, down, 360 degrees on all axis...

I also won't know if what I detect is the correct object...

#4