Need embedded systems expert and Android programmer for restaurant product
My company is launching a beverage-related product later this summer that requires a fair amount of automation. The device needs to monitor a couple 0-5V analog inputs (temperature and pressure), and based on these values and user input from three buttons, control five 5V relays that control five solenoid valves that control liquid and gas flow.
The current late-stage prototypes use an Arduino Uno controller and a very basic four-line LCD readout. However, I would like to experiment with using an inexpensive 7" Android tablet to replace the controller, screen, and physical buttons.
My intent would be to use USB relays (e.g., http://www.sainsmart.com/sainsmart
I'm not even absolutely sure this is possible on a device that has only one USB port)
So the job would be this:
1) Tell me if I'm crazy to even pursue this method; and, if not,
2) Prototype a quick-and-dirty application that has three buttons that can open and close three relays, while continuously reading an input voltage between zero and 5v. The voltage should be displayed on the screen. When the voltage is over a certain value (say 2.5V), relay #2 should be shut off (if on) and button #2 should be disabled.
3) For the purposes of this prototype, the analog input voltage will be just a simple battery and potentiometer to vary the voltage. As part of this job, describe how to get this voltage to the Android device via USB. If this is not simple (e.g., a couple alligator clips and resistors), then help me source an off-the-shelf item that will work.
If this can be demonstrated, we can move to the next step, and reproduce the current C code on the Arduino to get similar functionality on the Android device.
Thank you for your consideration.