====== Overview ======

 This document explain how to control ADC on the Odroid ADK board by Android ADK App.**
 PIC24FJ64GB002 is going to try read ADC value from voltage at the battery and the Variable Resistor, and transfer to Android ADK App.**
 ADK App display the result based on the ADC value.
----
 이 문서는 Odroid ADK Board 를 이용하여 ADC 를 제어하는 Android ADK app 를 설명한다. 
 PIC24FJ64GB002 칩은 밧데리와 가변저항의 전압을 ADC 값으로 읽어 와서, Android ADK app 으로 전달한다. 
 Android ADK App 는 ADC 값을 바탕으로 화면에 결과를 표시한다. 

====== What you need ======
  * ADK Board
  * ADK IO Kit 
  * Mini Breadboard
  * Variable Resister x 1ea 
  * jumper wires
====== Knowledge Base ======
===== Variable Resister =====
 
* Symbol
{{:en:vResister.jpg}}

===== ADC(Analog to Digital Converter) =====
Please refer to PIC24F Family Reference Manual, Sect. 17 10-Bit A/D Converter.([http://ww1.microchip.com/downloads/en/DeviceDoc/39705b.pdf])

====== Circuit ======
{{:en:Odroid_ADK_ADC_fz.png?520}}
{{:en:Odroid_ADK_ADC_pic.png}}

====== Schematic ======                   
{{:en:Odroid_ADK_ADC_schem.png}}

====== Video ======
 [http://www.youtube.com/watch?v=gjGIvDDPYD4]

 [[Play(http://www.youtube.com/embed/gjGIvDDPYD4?hl=ko&fs=1)]]

====== Software ======
**ADK** 
**svn check out**
**http://dev.odroid.com/svn/accessory/trunk/ODROIDAccessoryADCDemo**

<code>
    private void initDevice() {
        Log.e(TAG, "initDevice");
        // fix bug 
        // You must call function to use GPIO input mode, if firmware version is 1.0 
        initI2C();
        initBMP180();
        // fix bug 
        initADC(true);
    }   
</code>
초기화 후 handler에서 battery 값과 ADC 값을 읽어 표시하면 됩니다. 
<code>
        accessoryManager.read(commandPacket);

    switch(commandPacket[0]) {
        case RECEIVED_LETTER_ADC:                      
            value = (short) (commandPacket[3] << 8); 
            value |= (short) (commandPacket[4] & 0x00ff);
            updateADC(value);
            break;
                
        case RECEIVED_LETTER_BATT:
            value = (short) (commandPacket[3] << 8); 
            value |= (short) (commandPacket[4] & 0x00ff);
            updateBatt(value);
            break;
</code>
**Bluetooth**

**svn check out** 

**http://dev.odroid.com/svn/accessory/trunk/ODROIDBluetoothADCDemo**

**svn check out**

**http://dev.odroid.com/svn/accessory/trunk/ODROIDBluetoothADCDemo**

ADK 펌웨어에서는 자동으로 ADC와 Battery 값을 보내 주지만, BaB 펌웨어에서는 request해야 보내 줍니다.
그래서 Timer를 두어 protocal로 request를 보내고 받아서 처리하면 됩니다.
<code>
private void getADC() {
        //Log.e(TAG, "getADC");
        Message msg = Message.obtain(handler, SEND_LETTER_ADC_CONFIG, ADC_PORT, 0);
        handler.sendMessage(msg);
    }

private void getBattery() {
        //Log.e(TAG, "getBattery");
        Message msg = Message.obtain(handler, SEND_LETTER_BATT, 0, 0);
        handler.sendMessage(msg);
    }
</code>