Thanks Mike the ADXL202 look very interesting but I could not find a small quantity price for it. Just looking around I see that digi-key has an 3 axis accelerometer for 25.00 it looks like the kind of thing used in a gyro mouse. Jim -----Original Message----- From: Mike Pink To: PICLIST@MITVMA.MIT.EDU Date: Thursday, July 11, 2002 1:22 AM Subject: Re: [PIC]:how to use acceleration sensor for motion control? >Jim > >Just to add to my last you might want to look at Analog's ADXL202 or >ADXL05/50 > >Mike > > >----- Original Message ----- >From: "Jim" >To: >Sent: Wednesday, July 10, 2002 4:00 PM >Subject: Re: [PIC]:how to use acceleration sensor for motion control? > > >> Hello >> I'm building a small robot and was planning to build a tilt sensor that >> should measure acceleration to. >> I only have the idea I haven't done any testing yet. The idea is to make a >> small pendulum with a ferrite >> bead as the weight. Near this will be a coil that is part of a tank >circuit >> of an oscillator as the ferrite bead >> swings near or farther from the coil the frequency will change and I will >> keep track of it with one of the timer >> inputs on a PIC. The pendulum may need to be dampend. I once saw a small >> scale that had it's beam >> dampend by having a small copper plate attached to the beam swing near 2 >> small magnets this would >> cause eddy currents in the copper and dampen the beam movment. >> >> Regards >> Jim >> >> >> -----Original Message----- >> From: Pang accelerationacceleration >> To: PICLIST@MITVMA.MIT.EDU >> Date: Wednesday, July 10, 2002 12:47 AM >> Subject: Re: [PIC]:how to use acceleration sensor for motion control? >> >> >> >Hi, >> > >> >I have posted some questions on the area of acceleration sensor some >months >> >ago and gain a lot of knowledge from other piclisters. For searching >> >purpose, the subject of the thread is [EE]:Tilt Sensor. A two axis >> >accelerometer are basically used to detect both dynamic acceleration >> >(vibration) and static acceleration (gravity). As such, a dual axis >> >acceleration can be use to detect vibration, tilting, and acceleration. >> > >> >I have given up on searching for a tilt sensor solution because >> accelerators >> >are very expensive. ADXL202 is expensive and fragile. You can check also >> the >> >accelerators from Memsic, but they are also very expensive (USD14.50). >> > >> >As for the rotational sensor, piclisters has suggested on using a optical >> >encoder or ball bearing potentionmeter or electrolytic tilt sensor. Have >> yet >> >to get some samples on that. Perhaps you can consider these for >rotational >> >sensor. >> > >> >There could be others which I do not know. >> > >> >Rgds, >> >Pang >> > >> > >> > >> >Subject: [PIC]:how to use acceleration sensor for motion control? >> > >> > >> >need to control two dimension movement, speed and distance. or may be >even >> >rotation movement. >> > >> >how good sensor is needed? 0.01 mg , from analog device, enough? >> > >> >acceleration sensor should works, theorically. any example? site? >> > >> >BR, >> > >> >-- >> >http://www.piclist.com#nomail Going offline? Don't AutoReply us! >> >email listserv@mitvma.mit.edu with SET PICList DIGEST in the body >> > >> >-- >> >http://www.piclist.com hint: To leave the PICList >> >mailto:piclist-unsubscribe-request@mitvma.mit.edu >> > >> > >> > >> >> -- >> http://www.piclist.com hint: To leave the PICList >> mailto:piclist-unsubscribe-request@mitvma.mit.edu >> >> > >-- >http://www.piclist.com hint: PICList Posts must start with ONE topic: >[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads