May 01, 2013: Time has come to build the TX ultrasonic beacon. This time I wanted to try something new, so here is my first PCB for SMD components:
It uses a NE556, dual timer, and is configured to emit short bursts of 40KHz pulses. You can see the circuit here:Eagle file also available, beacon TX.
A case was also needed, to enclose the 9V battery as well, and make it comfortable for holding it in the hand. The final results looks like this: