Hi Martin, Nice looking application. As to the resolution good question. Maybe Andy K has some thoughts on this. I've never really determined how far you need to go. My current system (using an electrolytic tilt sensor) probably gives about 0.1 degree or so (maybe even better). Not sure exactly how good it needs to be though. I also noticed the problems with the power supplies for the device. Just having a R/C Servo on the same Bench power supply seems to create all sorts of problems! Andy ----- Original Message ----- From: "Martin Hill" To: Sent: Thursday, October 19, 2000 2:39 PM Subject: Re: [PIC]: Using 2 CCP: Compare failed if Capture event the same time > I have used them to measure vehicle performance, have a look at > the performance meter at www.ac22.com What sort of resolution > are you looking for? If you set the filter capacitors to give a slow > enough response you should be able to resolve to 5mg. > > Martin > > Got to ask Andy. What was the application? Can you say? Sounds interesting! > > I'm thinking of using the accelerometer for Tilt input but so far it seems > > sort of marginal in terms of resolution (I'm using the slightly older 2G > > sensor not the latest updated E version - I picked up a few a while ago and > > have just got around to using them). > > > > BTW have you ever used any of this stuff in any of those fast targets err > > surface craft you like to play around with. Is it possible to add any sort > > of stability enhancement (or would that spoil all of the fun...). > > > > Andy > > > > ----- Original Message ----- > > From: "Andrew Kunz" > > To: > > Sent: Wednesday, October 18, 2000 12:50 PM > > Subject: Re: [PIC]: Using 2 CCP: Compare failed if Capture event the same > > time > > > > > > > >Almost a correct guess. What I'm actually doing is using the capture > > input > > > >to read from and Analog devices accelerometer (which generates a PWM > > style > > > >output prop to the G force). But yes the compare part of the CCP is being > > > >used to generate an RC pulse! Actually I think I can simply switch > > between > > > >the two (I have the time available), I want to keep the two PWM chans to > > > >generate a set of PWM outputs for speed control! > > > > > > First, make sure you can get the part of Analog if you are making more > > than one. > > > They are really hard to get right now (I have several on order since May > > and > > > they're telling me April 2001) and will cost a lot more than they quoted > > > earlier. > > > > > > I have used this exact setup. Works great! > > > > > > You can keep the one input always set to the ADXL device and integrate the > > > results constantly (hint hint). > > > > > > The PWM output you can switch back and forth between two servos using a > > logic > > > chip (demux). Then you can update them as frequently as you want. I had > > a > > > design using a GAL to use the two channels as inputs, then flip one pin > > and some > > > software to turn them into outputs, and they would go out on another two > > pins > > > from the GAL. Super-accurate mixing, only used 3 pins to get 2 inputs and > > 2 > > > outputs with .5uS resolution. The logic was all very fast and short code, > > > leaving lots of codespace to do things like variable mix ratios, expo, > > etc. > > > > > > Andy > > > > > > -- > > > 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 > > > > -- http://www.piclist.com hint: PICList Posts must start with ONE topic: "[PIC]:","[SX]:","[AVR]:" =uP ONLY! "[EE]:","[OT]:" =Other "[BUY]:","[AD]:" =Ads