I have been reading with interest the sonar usage (right sensor, etc.) because I had already purchased the previously recommended sensor (EZ0) but had yet to add it to my quad. After reading the posts by Maxbotix and others, I went ahead and took the plunge. I added a 100uF capacitor directly to the board (photo above) as recommended and put a 100ohm resistor on the +5V line.
I created a cable and hand-braided it in an attempt to eliminate as much noise as possible. I know Maxbotix recommends a shielded cable but I didn't have any. The cable is also a little too long. I also temporarily mounted it to a paint stir and put it on the opposite side of the air-frame from the receiver. But as you can see from this photo, it is darn close to one of the prop tips too. But enough of that - how did it perform?
Here is the result of a test flight in pretty high wind.
First, I am continually surprised at how accurate the barometric height is. Second, the sonar trace has some decent readings for much of the flight, but sometimes is has crazy readings. I can't tell exactly what is going on here yet, but I'm going to track it down. I know the sonar I have is ultimately too sensitive and is probably picking up things like the mailbox (which was certainly nearby). Additionally, I wonder how likely it is to be hindered by heavy winds?
I'm going to do some more testing soon. I want to shorten the boom to get it further from the prop. If anybody has any testing methods they think are good for sonar units, please let me know.