Home ADB Microbridge Android + Arduino + USB Host + Simple Analog Input

Android + Arduino + USB Host + Simple Analog Input

Posted by michael on May 2, 2012 in ADB Microbridge, Android, Arduino, Tutorials | 6 comments

This worked for me.

Simplest possible analog input with the ADK. This article will discuss the bare minimal requirements for development of a basic USB input accessory. The goal is to demonstrate the easiest possible use of the technology. For additional background information on Android development, Arduino, and MicroBridge, check out these links:

Android Developer’s Guide
Getting Started with Arduino
Microbridge

Getting Started

First, make sure you have setup the development environments for Arduino and Android:

Arduino IDE
Android SDK

Hardware

Parts needed:

Android Device (1.6+)
Photocell
10K ohm resistor
Hook-up wire
Android ADK Board*
– OR –
Arduino compatible and USB Host shield

*Supported boards include:

Google ADK board, Freeduino ADK board , Seeed Studio ADK board, and DIY Drones ADK board

Assembly

Connect one of the photocell leads to 5v and the other to analog input pin A0. Also connect the same lead through a 10K resistor to ground. In hardware, this concept is known as a voltage divider. Here is a diagram of the completed circuit (created with Fritzing):

Software

Arduino Firmware

Next, upload the Arduino sketch to the microcontroller. The sketch uses the Microbridgeimplementation by Niels Brouwers. Microbridge uses Android Debug Bridge (ABD) forwarding over TCP, rather than the Google Android ADK. You can checkout the source for the Arduino sketch from Github, or just copy and paste the following into the Arduino IDE.

#include <SPI.h> #include <Adb.h> Connection * connection; // Elapsed time for sensor sampling long lastTime; // Event handler for shell connection; called whenever data sent from Android to Microcontroller void adbEventHandler(Connection * connection, adb_eventType event, uint16_t length, uint8_t * data) { // Unused in this case } void setup() { // Record time for sensor polling timer lastTime = millis(); // Init the ADB subsystem. ADB::init(); // Open an ADB stream to the phone's shell. Auto-reconnect. Use port number 4568 connection = ADB::addConnection("tcp:4568", true, adbEventHandler); } void loop() { //Check if sensor should be sampled. if ((millis() - lastTime) > 20) { uint16_t data = analogRead(A0); //Send the sensor value to Android as two bytes of data. connection->write(2,(uint8_t*)&data); Serial.println(data,DEC); // Output debugging to serial // Update timer for sensor check lastTime = millis(); } // Poll the ADB subsystem. ADB::poll(); }

Android App

The next step is to install the Android Demo application onto the device. You can either download the pre-built .apk or checkout the source from Github:

git clone git://github.com/mitchtech/android_adb_simple_analog_input.git

Finally upload the app to the device (or browse to this page on the device and download the apk above). Connect the Android device to the USB Host board/shield, and start up the app.

6 Comments

kyle kim
October 13, 2012

this source comes up error message… plz help me

reply
- kyle
  October 13, 2012
  
  ADB_Simple_Analog_Input.pde:-1: error: variable or field ‘adbEventHandler’ declared void
  ADB_Simple_Analog_Input.pde:-1: error: ‘adb_eventType’ was not declared in this scope
  ADB_Simple_Analog_Input.pde:-1: error: expected primary-expression before ‘length’
  ADB_Simple_Analog_Input.pde:-1: error: expected constructor, destructor, or type conversion before ‘long’
  ADB_Simple_Analog_Input.pde:-1: error: variable or field ‘adbEventHandler’ declared void
  ADB_Simple_Analog_Input.pde:-1: error: ‘adb_eventType’ was not declared in this scope
  ADB_Simple_Analog_Input.pde:-1: error: expected primary-expression before ‘length’
  ADB_Simple_Analog_Input.cpp: In function ‘void setup()’:
  ADB_Simple_Analog_Input.pde:-1: error: ‘lastTime’ was not declared in this scope
  ADB_Simple_Analog_Input.pde:-1: error: ‘ADB’ has not been declared
  ADB_Simple_Analog_Input.pde:-1: error: ‘connection’ was not declared in this scope
  ADB_Simple_Analog_Input.pde:-1: error: ‘ADB’ has not been declared
  ADB_Simple_Analog_Input.pde:-1: error: ‘adbEventHandler’ was not declared in this scope
  ADB_Simple_Analog_Input.cpp: In function ‘void loop()’:
  ADB_Simple_Analog_Input.pde:-1: error: ‘lastTime’ was not declared in this scope
  ADB_Simple_Analog_Input.pde:-1: error: ‘connection’ was not declared in this scope
  ADB_Simple_Analog_Input.pde:-1: error: ‘ADB’ has not been declared
  
  reply
  - michael
    October 22, 2012
    
    Hi Kyle, have you installed the Microbridge library? If not, you will need to download the Adb library here and unpack it into the libraries directory of your Arduino installation as described in the Getting Started guide for Microbridge.
    
    reply
    - kyle
      November 4, 2012
      
      hi~~
      Thanks to your help, I solved this problem.
      but i have one more problem….
      After uploading cell phone and tried to connect the Arduino board does not operate.
      i need your help plz…
      
      reply
      - michael
        November 4, 2012
        
        Do you have USB debugging enabled on your Android device? On the device, go to Settings > Applications > Development and enable USB debugging (on an Android 4.0+ device, the setting is located in Settings > Developer options).
ade salau
March 5, 2013

I get a error message saying boolean does not name a type when uploading

reply

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Android + Arduino + USB Host + Simple Analog Input

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