How can I control a pet autofeeder with LABview?

[kyjapo]

Hi all, I'm trying to use LABview to feed and provide water for my pet while I'm away from home. I want to perform this task at the same time each day and refill food/water to a starting setpoint (this way the autofeeder dispenses little when little is eaten and a lot when a lot is eaten). I'm less worried about the software part of LABview. I don't know what general hardware I should start with. I figure I'll use a control valve for the water from my sink, but am confused on even how to wire it to my computer to perform this task. If anyone has any suggestions or solutions, I would greatly appreciate it. Thank you.

[M_S]

 Hi,

     My suggestion is use your PC Parallel port for install testing. Through this port u can control the valve also.

 

[smercurio_fc]

---

M S wrote:

 Hi,

     My suggestion is use your PC Parallel port for install testing. Through this port u can control the valve also.

---

And if the computer doesn't have a parallel port (like most computers nowadays)? Also, connecting hardware directly to a parallel port is a BAD idea - very easy to damage your motherboard that way.

As to the query:

In any event, you will need sensors and actuators. What kind of sensors depends on what you're trying to sense. There are various sensors for measuring water level on the market. Some are designed for standing water, and others are designed for use in water that tends to "slosh". As for the food level, perhaps a weight sensor is your best option. These sensors invariable generate a voltage signal that is in some way proportional to the physical entity that they are measuring. They will need some sort of excitation in order to actually generate the voltage. In order to connect all of this to your computer you will need some data acquisition product. Something that can take in a voltage and interface to a computer. NI has several USB-based products. Then you'd need to write the program. Then you'd need to test it for various conditions. 

Sure it wouldn't be easier to drop off your pet with someone to look after them or perhaps get something from autopetfeeder.com?  

[kyjapo]

Thanks for replying. So I just have to use a sensor to determine the food/water level, send a voltage signal to the computer, interpret the signal, and have the computer send a signal to another device that fill up the food bowl or water bowl.  I guess i could use a solenoid valve for the water.  I really can't think of anything with the food dispensing though. The only remote idea i can think of is to use a door to allow the food to fall into the bowl, but are there remote doors on market that can hold the weight of a tank of food and that can receive signals from the computer?  Does anyone know of any hardware that i could use?

[Henrik_Volkers]

Do you know the VCR cat feeder?

For easy LabVIEW IO a USB 600X or a labjack is nice. If 2(+1) digital input and 2(+1) dig out are enough and you know how to build a PCB a simple USB2RS232 (<10$) will do the job.

[JCall]

Instead of using a door, you could use an auger screw in a tube with a hopper full of pet food attached above it. Then you attach a small motor to the screw, and use LabVIEW to power the motor some desired amount of time/steps/etc however many times per day. You'll just have to figure out how many screw turns it takes to shovel enough food through the tube and out into the bowl. Once you have that figured out, you may not even need a feedback mechanism.