External USB devices to Android phones?

Question

I would like to use Android phones as a way to do some processing and visualization of a sensor that would be attached to the USB port on the phone. The sensor would plug in

Answer 1

The USB defines two type of equipment 1 usb host 2usb device .A device can only be attached to a host,no host to host or device to device connection.,in the beginning usb hosts were computers to which a usb device is attached.but with increase in popularity of usb interface a number of equipments come as usb host ie you can attach your pendrive and other usb device to it.In the starting mobile phones were manufactured as usb device ie you can attach your phone to usb host only typically a computer.but there also revolution come in now we have phone which can act as host and device when it is working as host we can attatch printer to it and when it work as device it can be attatched to a computer.only high end phone has this support.low end phones are still usb devices. so we have two options

1. phone in usb host mode and your senser as usb device(you will need microcontroller that can act as usb device for this purpose-eg pic 18f2550 microcontroller);
2. your phone as device and your senser circuit as usb host here you will need high end microcontrollers that can act as usb host

in both cases there involves coding at both phone and senser circuit microcontroller

i dont know anything about phone side coding but i think this helps you to get a direction to what to do.