Hi all, I wanted top build a ultrasonic system for my robot. The range i need for the sensor is about 5 cm - 2 m. I have searched through the archive of this mailing list, and I found the link from one of Matt Bennett e-mail. Matt wrote: Check out this page, it looks like what you want: very simple. I've seen the webpage and have some quiries regarding the ultrasonic sensor. 1. The product code of the sensor is MA40A3R and MA40A3S. However, I couldn't find such product code in the murata homepage. Can I Use another product code?? 2. I've read the product specification and found that the min. detectable range is 20 cm. Based on this specification, can I modify the min. range to about 5cm ?? 3. What is the meaning of maximum input voltage 20 Vp-p?? is it 0V to 20V or -10V to +10V ? 4. According to the specification, the input voltage type can be continuous or pulse width with interval. What is the difference of the two?? I really appreciate if you all can help me =) Thank you for your attention. Erwin Stevanus _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads