Was just wondering if there is available, any pre-built, quality, SEPARATE ultrasonic transmitter/receivers ... a separate transmitter, with a separate receiver. I see many quality ultrasonic range finders, etc. ... and I've found schematics for building such devices (usually it's the link to the same 10-year old 'ultrasonic switch' schematic) but was wondering if anyone offers just a transmitter, with just an accompanying receiver.
A simple transmit a pulse and "Yes, I've received the pulse" receiver pair.
I will probably build one using the old schematic, but was wondering if there are any pre-assembled units out there.