Hi i was wondering if you could help.
I based my rangefinder for a project on your SRF04 and i have had loads of
problems with my design because I dont fully understand it..http://www.robot-electronics.co.uk/files/srf1.pdf
Basically i was wondering, how do you come to the calculations of c6 and
r7 values for the delay RC for the comparator?
Its not a simple R*C - gives time delay is it?
Also I was wondering in the circuit, what kind of voltages would you expect
GP4, gp5 - from the PIC and TX1?
P.s am i right in saying that the input impedance R12 is a bit small
(transducer impedance not taking into account?) also C9 is a little
excessive for 40khz? It could be smaller to still block the required DC and pass AC