"Kresho @ Advanced Technika" wrote: >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. > Yes, it does sound weird... >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. > If the height of the cup is consistent enough, could you perhaps interrupt a light beam when the froth breaks over the top rim of the cup? (Depending on ambient light conditions, this may or may not be feasible but it may be worth considering.) Given the nature of the froth, sensing its height from above could make it very difficult to get any great degree of accuracy in your measurement. Regards, Bob _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu