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I want a device similar to what ShopKick That produces a high pitch sound that can not be heard by humans.
-Sound must be coded with a unique sound code that will be picked by smartphones, each device must have a unique sound code.
-The device must cover large spaces with obstacles and noise.
-The device must produce high pitch sound with more than 21khz that cant be heard by humans
-I will need the demo device to be shipped to my country.
-I will also need the documentation to reassemble this device and circuit design.
-220v plugin input.
- The most important thing to keep in mind is that the device components and assembling cost must be as low as possible(for later production).