How to control Android app with Arduino

Question

I'm trying to connect Arduino Leonardo to an Android tablet. I would like to make the Arduino send commands (using pushbuttons or a slider for example) to the tablet to switch between pages, to select a file on the desktop, to scroll up and down the screen, etc.

Answer 1

Perhaps this is not exactly what you are looking for, but from your examples it seems like using navigational commands from the keayboard/mouse would accomplish a lot of what you are requesting.

Android has USB HID support from honecomb, so you should be able to create a sketch to emulate a keyboard and mouse based on the IO data and it should work with your android device just by plugging the USB cable (if emulating a mouse, it will display the mouse cursor as soon as it is connected).

Answer 2

First, get a Lightblue Bean, http://punchthrough.com/bean/

It has everything you need: - arduino - bluetooth - API - code example - android sdk - ...

Develop your product using this platform.

If you want to scale and build your own platform, then you will have a foundation to validate your work.

• Connor Wolf: Half you answers refer to this product. Are you associated with it? You need to disclose any personal stake in it if you are.
• albator: not associated with the company, but a happy customer of their product.

Answer 3

It is a good idea to use a LightBlue Bean, only if you are using the Android SDK! https://bitbucket.org/littlerobots/beanlib

You can read more about the SDK, and get advice from people who are actually using it. http://beantalk.punchthrough.com/t/announcing-unofficial-android-sdk/394

Answer 4

Android code:

function OnStart() {
 //Create a layout with objects vertically centered.
 lay = app.CreateLayout("linear", "VCenter,FillXY") 
 //Create a toggle button.
 btn = app.CreateToggle("LED On/Off", 0.4)
 btn.SetOnTouch(btn_OnTouch)
 lay.AddChild(btn)
 //Add layout to app. 
 app.AddLayout(lay)
 //Create USB serial object.
 usb = app.CreateUSBSerial() 
 if (!usb) {
 app.ShowPopup("Please connect your Arduino and restart")
 return;
 }
 usb.SetOnReceive(usb_OnReceive)
 app.ShowPopup("Connected")
}
//Called when user touches our toggle button.
function btn_OnTouch(isChecked) {
 if (!usb) return;
 
 //Send LED command to Uno.
 if (isChecked) usb.Write("ledh")
 else usb.Write("ledl")
}
//Called when we get data from Espruino.
function usb_OnReceive(data) {
 console.log(data)
}

Arduino code:

void setup() {
 pinMode(2,1);
 serial.begin(9600);
 
 loop() {
 if (serial.Read()="ledh) {
 digitalWrite(2,1);
 }
 if (serial.Read()="ledl) {
 digitalWrite(2,0);
 }
 }
}

• tripleee: The Arduino code has clear syntax errors; please review.
• Juraj: this doesn't answer the question. OP wants to use USB HID capability (emulate keyboard) of the Leonardo