I goofed in my original series of posting concerning the ultrasonic IO circuit. The circuit is used to interface automotive ultrasonic sensors. The circuit allows transmitting and receiving signals. I’m not sure what was going on in the original posting but the circuit I showed was terribly wrong. It was over four years ago when I posted the original so I’m not sure what I was thinking back then. Anyway, the image at right shows what I think is the correct circuit. Luckily, I was able to pull out the original proto board I built from four years ago. Cause I never throw anything away!
Just in case, below are a bunch of pictures I took of the board. I’ve tried to take a bunch of pictures so you too can reverse engineer my old working circuit. The pictures show both the front and backside of the board in high resolution.
Sorry if my original crappy circuit goofed anyone! Oh, and thanks goes to Sebastian for pointing out my blunder. Hope this new circuit diagram helps.