On 6/11/05, b_prasana <[EMAIL PROTECTED]> wrote: > Dear Friends > > I am a E.C.E. student entering in to third year. I want > to do a project ,i.e., > > A water level indicator using 8085 microprocessor and > 8255 interface. > Can anyone help me in this regard, like how to get > about it? > With regards > B.Prasana >
I suspect - as this is a sensor based question, that posting on both the OrionRobots forums (http://orionrobots.co.uk/forums.php) and the DPRG list would get a response from people who have done this before. Just out of interest- why choose the 8085? Or was that determined by the course? I would have chosen a PIC for this you see. What do you intend for the water level sensor? You could use a discrete set of conductors - which would then be conducting when they are each below the water level. In which case - although it is digital, you may want to clean up the signal between the water and the 8255 with a single transistor. You could also use a float, with a rotation sensor - like a variable resistor. You would then use an A to D between this and the 8255, or a biased transistor to switch when it reaches a certain level. One well documented property of water is that the interface between it and air causes light to refract - so by calculating (or measuring) the angles, you could set up an IR based system that will detect when the light is reflected at a certain angle form the bottom of the tank, the angle is determined by the refraction - which is determined by the water depth. This could be done with a single IR Led, and a Phototransistor - keeping the electronics simple. You would then use guides to ensure the angles the light is being emitted and received. You will need to ensure the bottom of the water container is reflective. If you use the electronics to set a threshold, then you could use the 8255 in mode 1 or 2 and use control signals to interrupt the CPU, and respond to that. However- if you want the A to D continuous based monitoring - then you are better off writting a program to regularly poll the port and test the values on that. Good luck, Orion -- http://orionrobots.co.uk - Build Robots Online Castle Building RPG - http://www.darkthrone.com/recruit.dt?uid=V30311I30328J30379X30379E30260X30277 Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/tech4all/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
