"Hello! This is Tom Bonar from MaxBotix Inc. @Thor Larsen   1. Electrical noise & proper shielding and grounding. 2. If you don't fix the noise problems or they aren't sure how. swith to the MB1220 Hardware gain of…"

"Hi Thor, In my case I could reduce quite a lot the sonar alt measurements noise / spikes with the BEC from this shop: http://store.jdrones.com/3Amp_5V_uBEC_Low_Noise_p/ubec3a01.htm and placing the sonar sensor (MB 1200) on my Storm Drone…"

"Funny about flying over grass... I have yet to fly my 3DR quad, but I have been tuning a good deal in my office (with carpeted floors).  When sitting on my desk, motors running or not (no propellers attached), the ALT readings seemed to be very…"

"Hi Randy, on Sept. 23 you showed two sonar signal graphs (before and after shots). Did you have only noise and spikes when you alter the throttle? In my case I have only noise and spikes when altering the throttle value. Otherwise the sonar values…"

"Hi Kure, did you resolve the problem in the meantime. I have the same problem with the APM 2 on a Storm Drone from www.helipal.com .  The best I can achieve with altitude PID tuning is a correct working of alt hold at low altitude for some…"

"Oh, I already had the capacitor soldered onto the sonar, so it's not in the pictures."

"How I made my cable: I cut up Audio/Video cables I had laying around the house until I found one that was shielded. I cut the ends off and stripped back the insulation.  Then I twisted all the shields together at one end, and I choose…"

"Following.  ;)"

"AHA!!!!! Another flight, and I noticed something. As I flew over my driveway, the data got clean as whistle. Then when I flew over grass again, it went back to a mess of data spikes. Flying over cement doesn't give 100% clean data, but…"

"Another extreme measure at getting good sonar data. Built my upteenth cable, this time each wire is individually shielded and grounded at the apm side. I extended the sonar way out about 6 inches (10cm), it has the power supply RC filter…"

"What? Great. This is awesome. I was about to sen payment for use GoPro Hero2.:) Deal canceled.;) hehehe.. 12:01 Tick tick tick...."

"Message me if you are still interested. Thanks."

"KUR you misunderstood what I said. I said it has APM1 which is older version and now APM 2.5 is available. I didnt mean that USED APM1. I know who ever put his stuff here online is used. As a student I dont have much money so I can afford only 300$…"

"Ahmad, Thank you for your interest. Its really not a USED APM1. If you are referring to the flight time on this APM then its totally brand new. I have less than 10mins on it. But you can throw your offer at me. I just have to say YES or NO.…"

"Hello I am interested in this unit. What will be your final sale price. It used APM 1 so the price is too high for this version of APM."

"PM Sent."