I have not been following this thread, so excuse me if this idea was already suggested, but ---- use "dark" colored coffee mugs, and devise a scheme to visually measure the width of the dark horizontal line between the top of the cup and the top of the froth. You will have a very good high-contrast area, which should make sensing relatively easy. hope this helps, - dan michaels www.oricomtech.com ========================= At 11:38 AM 5/28/01 -0400, you wrote: >Your application has the following characteristics:- >1. it needs indirect contact sensing. >2. there is a certain degree of uncertainness on the parameters to acquire. >3. the sensing system needs some flexibility to accomodate variation. > >How about using a PC based image processing system if budget allows? > > >>From: "Kresho @ Advanced Technika" >>Reply-To: pic microcontroller discussion list >>To: PICLIST@MITVMA.MIT.EDU >>Subject: [EE]: detecting milk froth >>Date: Sun, 27 May 2001 11:45:28 +1000 >> >>Hello All. >> >>This might sound like a weird one but maybe someone can help. >> >>I'm trying to detect when some milk froth comes to the top of a cup for an >>automatic cappuccino maker. The cup will always be the same size and will >>have a coffee base already in it. What i want to do is place this cup under >>a nozzle and press a button so that milk froth is poured into the cup till >>it reaches a set height so that the cappuccino making is more of an >>automated process. >> >>Measuring weight is a no-goer since the froth is very light can vary in >>density. Using some probes may be troublesome because the froth will stick >>to them over time. Timing alone is also unsuitable. A distance measurement >>device which can operate over the required range (5-10cm) might be an idea >>but then again i don't know how well milk froth can be sensed since it is >>not very solid. >> >>Hope someone can help. >> >>Regards, Kresho >>Sydney, Aust. >> >>-- >>http://www.piclist.com hint: To leave the PICList >>mailto:piclist-unsubscribe-request@mitvma.mit.edu >> >> > >_________________________________________________________________________ >Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. > >-- >http://www.piclist.com hint: The list server can filter out subtopics >(like ads or off topics) for you. See http://www.piclist.com/#topics > > > > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics