555 timer radio beacon
Taken by Odd Stråbø, 2015-01-09 20:01:48 using Canon EOS 550D
555 timer as an (astable circuit)[http://en.wikipedia.org/wiki/555_timer_IC#Astable], R1 and R2 =10kOhm, C1 = 100µF, turning on and off the data pin on a (RF Link Transmitter - 434MHz)[https://www.sparkfun.com/products/10534]