Help with External Sensors for Android

Projects General Guidance
1

Hello, guys!
I'm new to electronics, but I have come up with an idea but got into confusions after I have done a huge amount of research online.

My idea is to build an external temperature device that connect to Android via USB ( USB host mode so it can supply the power to run the sensor the microcontroller) and take the reading of the sensor and send back to the android device.

Here is my question:

  1. Is there any chance that I can just connect a small microcontroller(ATtiny 85 or some short) with the sensor and connect it directly(or some converter) to the android device via USB and get the reading out of it?

  2. If I cant what is the easiest way to get this project done? I know that the output of the sensor is analog voltage, then do I need to convert that analog voltage signal into some kind of data that android device can read via USB port.if so how can I do that?

  3. Is there any platform available out there to simplify my project?

  4. Do I really need a microcontroller? or can I just used some kind of omh-aps circuit?

I am a newbie in electronics so my question must be dumb, Anyone past by the post i am much-appreciated ether you can help me or not!

Thanks, Arduino community!

2

You need a device (controller board) with an USB output. Arduinos emulate by default a serial USB device, so that you have to open an COM port (or equivalent) on Android, then listen for data sent from Arduino by Serial.print().

3

Do you have any link or diagram that show the connections? or any suggestion controller board >? because your answer give me more question :))

4

Do you know how to interface with a serial device over the Android's USB connection?

While I certainly think it's possible to use an Android as an USB host, I personally don't know how to use an Android this way.

If I were to try something like this (which I have) I'd use a Bluetooth module for communication between the microcontroller and the Arduino. If you know how to use a wired connection, then great; it's usually better to use a wired connection than a wireless connection when practical.

I don't think an ATtiny85 would be a good choice for this application. I think you'd be better off with a chip with an UART. There is an ATtiny with an UART but I don't recall the model number off hand.

I doubt there's an easy way to do this project without a microcontroller.

5

I suspect you would have to choose things a bit carefully, not the least being the Android USB host app, and ensure that there will be sufficient power available via USB host. I have never seen any app for use with USB that would persuade me that it is a better way to travel than collecting the data via bluetooth.

You don't actually say you have a power problem, and I don't think you are really thinking through the realities of what you are doing. While I don't have a power problem, if I did, I would fix it with batteries rather than try powering it with an Android. My Androids have better things to do.