en:c_tinkering [ODROID Wiki]

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====== Introduction C Tinkering Kit on Ubuntu ======
{{http://dn.odroid.com/homebackup/C-Breadboard1H.jpg?500|}}

You're probably itching to make some fun embedded computer projects with **ODROID-C**. What you need is an add on prototyping T-breakout board, which can break out all those tasty power, GPIO, I2C, ADC pins from the 40 pin header onto a solderless breadboard. This set will make "cobbling together" prototypes with the **ODROID-C** super easy.

This kit comes with below many items.
  * Assembled T-breakout PCB - 40Pin GPIO Breakout board
  * Breadboard - 630 Tie-points with dual power lanes
  * 40pin Ribbon cable - IDC Flat cable 100mm
  * 40pin Male-to-Male Dupont jumper Wire 170mm
  * 7 x Green LED 3mm
  * 7 x Yellow LED 3mm
  * 7 x Red LED 3mm
  * 2 x Photo Cell (CdS Light sensor)
  * 6 x Tact Switchs
  * 50 x 330 Ohm 1/6W resister
  * 50 x 10K Ohm 1/6W resister



[[http://www.hardkernel.com/main/products/prdt_info.php?g_code=G141637532784|Where to buy]]

====== DIY light level meter project ======
Configuration tinkering kit such as below schematic.

Please refer to below links for ODROID-C2 user or details related to gpio mapping.

[[en:c1_hardware#expansion_connectors | C1 Expansion Connectors]]\\
[[en:c2_hardware#expansion_connectors | C2 Expansion Connectors]]

{{:en:c1:tinkering.jpg?500|}}

===== Linux =====
==== C example (With WiringPi) ====
1. Get the wiringPi library compatible **ODROID**

  sudo apt update && sudo apt install git
  git clone https://github.com/hardkernel/wiringPi

2. Build the library

  cd wiringPi
  ./build

3. Compile and run the example source code.

{{http://dn.odroid.com/source_peripherals/ctinkeringkit/example-led.c|example-led.c}}
  wget http://dn.odroid.com/source_peripherals/ctinkeringkit/example-led.c
  gcc -o example-led example-led.c -lwiringPi -lwiringPiDev -lpthread
  sudo ./example-led

==== Python example ====

  * [[https://github.com/hardkernel/WiringPi2-Python|WiringPi2-Python repository for ODROID]]

**Prerequisites**: You must have //**python-dev**// and //**python-setuptools**// installed If you manually rebuild the bindings with swig-python wiringpi.i

  sudo apt-get install python-dev python-setuptools swig3.0
  
1. Get/setup WiringPi 2 for Python repository

<code>
git clone https://github.com/hardkernel/WiringPi2-Python.git
cd WiringPi2-Python
git submodule init
git submodule update
</code>

2. Build & install
<code>
swig3.0 -python -threads wiringpi.i
sudo python setup.py install
</code>
Or
<code>
./build.sh
</code>

3. Get/Run the example source code

{{http://dn.odroid.com/source_peripherals/ctinkeringkit/example-led.py|example-led.py}}
  wget http://dn.odroid.com/source_peripherals/ctinkeringkit/example-led.py
  sudo python example-led.py

===== Android =====

This process explains how to make an Android app which can access IO ports.\\
You need to install Google Android SDK/NDK on your host PC first to start below steps.

Insert this line into your ~/.bashrc file.

<code>
export NDK_PATH=/home/xxx/android-ndk-r10d
</code>

1. Download the wiringPi library and example App source code.
<code>
# git clone https://github.com/codewalkerster/example-led
</code>

2. Build a JNI library
<code>
$ cd example-led
$ cd jni
$ ndk-build
Android NDK: WARNING: APP_PLATFORM android-16 is larger than android:minSdkVersion 7 in /media/codewalker/92fc070a-3bc1-43e0-af27-03d08ba9dd3e/home/codewalker/workspace/xxxx/example-led/AndroidManifest.xml    
[armeabi] Compile thumb  : wiringPi <= wiringPi.c
/media/codewalker/92fc070a-3bc1-43e0-af27-03d08ba9dd3e/home/codewalker/workspace/xxxx/example-led/jni/wiringPi/wiringPi.c:147:0: warning: "PAGE_SIZE" redefined [enabled by default]
 #define PAGE_SIZE   (4*1024)
 ^
In file included from /home/codewalker/projects/android-ndk-r10d/platforms/android-21/arch-arm/usr/include/signal.h:34:0,
                 from /home/codewalker/projects/android-ndk-r10d/platforms/android-21/arch-arm/usr/include/poll.h:34,
                 from /media/codewalker/92fc070a-3bc1-43e0-af27-03d08ba9dd3e/home/codewalker/workspace/xxxx/example-led/jni/wiringPi/wiringPi.c:59:
/home/codewalker/projects/android-ndk-r10d/platforms/android-21/arch-arm/usr/include/limits.h:119:0: note: this is the location of the previous definition
 #define PAGE_SIZE 4096
 ^
/media/codewalker/92fc070a-3bc1-43e0-af27-03d08ba9dd3e/home/codewalker/workspace/xxxx/example-led/jni/wiringPi/wiringPi.c: In function 'interruptHandler':
/media/codewalker/92fc070a-3bc1-43e0-af27-03d08ba9dd3e/home/codewalker/workspace/xxxx/example-led/jni/wiringPi/wiringPi.c:1865:7: warning: return makes pointer from integer without a cast [enabled by default]
       return wiringPiFailure (WPI_FATAL, "wiringPiISR: wiringPi has not been initialised. Unable to continue.\n") ;
       ^
[armeabi] Compile thumb  : wiringPi <= wiringShift.c
[armeabi] Compile thumb  : wiringPi <= piHiPri.c
[armeabi] Compile thumb  : wiringPi <= piThread.c
[armeabi] Compile thumb  : wiringPi <= wiringPiSPI.c
[armeabi] Compile thumb  : wiringPi <= wiringPiI2C.c
[armeabi] Compile thumb  : wiringPi <= softPwm.c
[armeabi] Compile thumb  : wiringPi <= softTone.c
[armeabi] Compile thumb  : wiringPi <= mcp23008.c
[armeabi] Compile thumb  : wiringPi <= mcp23016.c
[armeabi] Compile thumb  : wiringPi <= mcp23017.c
[armeabi] Compile thumb  : wiringPi <= mcp23s08.c
[armeabi] Compile thumb  : wiringPi <= mcp23s17.c
[armeabi] Compile thumb  : wiringPi <= sr595.c
[armeabi] Compile thumb  : wiringPi <= pcf8574.c
[armeabi] Compile thumb  : wiringPi <= pcf8591.c
[armeabi] Compile thumb  : wiringPi <= mcp3002.c
[armeabi] Compile thumb  : wiringPi <= mcp3004.c
[armeabi] Compile thumb  : wiringPi <= mcp4802.c
[armeabi] Compile thumb  : wiringPi <= mcp3422.c
[armeabi] Compile thumb  : wiringPi <= max31855.c
[armeabi] Compile thumb  : wiringPi <= max5322.c
[armeabi] Compile thumb  : wiringPi <= sn3218.c
[armeabi] SharedLibrary  : libwiringPi.so
[armeabi] Install        : libwiringPi.so => libs/armeabi/libwiringPi.so
[armeabi] Compile thumb  : wiringPiDev <= ds1302.c
[armeabi] Compile thumb  : wiringPiDev <= maxdetect.c
[armeabi] Compile thumb  : wiringPiDev <= piNes.c
[armeabi] Compile thumb  : wiringPiDev <= gertboard.c
[armeabi] Compile thumb  : wiringPiDev <= piFace.c
[armeabi] Compile thumb  : wiringPiDev <= lcd128x64.c
[armeabi] Compile thumb  : wiringPiDev <= lcd.c
[armeabi] Compile thumb  : wiringPiDev <= piGlow.c
[armeabi] SharedLibrary  : libwiringPiDev.so
[armeabi] Install        : libwiringPiDev.so => libs/armeabi/libwiringPiDev.so
[armeabi] Compile thumb  : wpi_android <= wpi_android.c
[armeabi] SharedLibrary  : libwpi_android.so
[armeabi] Install        : libwpi_android.so => libs/armeabi/libwpi_android.so 
</code>

3. Import existing project to the eclipse IDE.

{{http://dn.odroid.com/Tinkering_Kit/Screenshot%20from%202015-04-10%2010:41:11.png?500|}}

4. Run example-led

{{http://dn.odroid.com/Tinkering_Kit/device-2015-04-10-103856.png?600|}}

[[https://www.youtube.com/watch?v=zyfULOkj0Vw|]]

5. Source code browsing!

**//Add below items in jni/Android.mk to build libwingPi.so and libwingPiDev.so//** 
<code>
include $(CLEAR_VARS)
LOCAL_C_INCLUDES += \
    $(NDK_PATH)/platforms/android-21/arch-arm/usr/include \
    $(LOCAL_PATH)/wiringPi

LOCAL_MODULE    := wiringPi
LOCAL_SRC_FILES := \
    wiringPi/wiringPi.c \
    wiringPi/wiringShift.c \
    wiringPi/piHiPri.c \
    wiringPi/piThread.c \
    wiringPi/wiringPiSPI.c \
    wiringPi/wiringPiI2C.c \
    wiringPi/softPwm.c \
    wiringPi/softTone.c \
    wiringPi/mcp23008.c \
    wiringPi/mcp23016.c \
    wiringPi/mcp23017.c \
    wiringPi/mcp23s08.c \
    wiringPi/mcp23s17.c \
    wiringPi/sr595.c \
    wiringPi/pcf8574.c \
    wiringPi/pcf8591.c \
    wiringPi/mcp3002.c \
    wiringPi/mcp3004.c \
    wiringPi/mcp4802.c \
    wiringPi/mcp3422.c \
    wiringPi/max31855.c \
    wiringPi/max5322.c \
    wiringPi/sn3218.c

LOCAL_CFLAGS    += -UNDEBUG -DANDROID

LOCAL_LDLIBS    := -ldl -llog
include $(BUILD_SHARED_LIBRARY)


include $(CLEAR_VARS)
LOCAL_C_INCLUDES += \
    $(NDK_PATH)/platforms/android-21/arch-arm/usr/include \
    $(LOCAL_PATH)/wiringPi

LOCAL_MODULE    := wiringPiDev
LOCAL_SRC_FILES := \
    devLib/ds1302.c \
    devLib/maxdetect.c \
    devLib/piNes.c \
    devLib/gertboard.c \
    devLib/piFace.c \
    devLib/lcd128x64.c \
    devLib/lcd.c \
    devLib/piGlow.c

LOCAL_SHARED_LIBRARIES := libwiringPi

LOCAL_CFLAGS    += -UNDEBUG
include $(BUILD_SHARED_LIBRARY)
</code>

//**Make some JNI API functions to access the wirinPi library.**//
<code>
jint Java_com_hardkernel_wiringpi_MainActivity_analogRead(JNIEnv* env, jobject obj, jint port) {
    return analogRead(port);
}

void Java_com_hardkernel_wiringpi_MainActivity_digitalWrite(JNIEnv* env, jobject obj, jint port, jint onoff) {
    digitalWrite(port, onoff);
}

int Java_com_hardkernel_wiringpi_MainActivity_wiringPiSetupSys(JNIEnv* env, jobject obj) {
    wiringPiSetupSys();
    return 0;
}
</code>

//**Declare GPIO ports.**//
<code>
    private final int ledPorts[] = {
        97, // GPIOX.BIT0(#97)
        108, // GPIOX.BIT11(#108)
        100, // GPIOX.BIT3(#100)
        101, // GPIOX.BIT4(#101)
        105, // GPIOX.BIT8(#105)
        106, // GPIOX.BIT9(#106)
        107, // GPIOX.BIT10(#107)
        115,  // GPIOX.BIT18(#115)
        116,  // GPIOX.BIT19(#116)
        88,  // GPIOY.BIT8(#88)
        83,  // GPIOY.BIT3(#83)
        87,  // GPIOY.BIT7(#87)
        104,  // GPIOX.BIT7(#104)
        102,  // GPIOX.BIT5(#102)
        103,  // GPIOX.BIT6(#103)
        117, // GPIOX.BIT20(#117)
        99, // GPIOX.BIT2(#99)
        118, // GPIOX.BIT21(#118)
        98, // GPIOX.BIT1(#98)
    };
</code>

//**Define JNI functions**//
<code>
    public native int wiringPiSetupSys();
    public native int analogRead(int port);
    public native void digitalWrite(int port, int onoff);

    static {
        System.loadLibrary("wpi_android");
    }
</code>

//**Generate GPIO access nodes**//
Make SYSFS GPIO access nodes with the /sys/class/gpio/export \\
Change the GPIO pins to output mode via direction node.\\ Don't forget to change the permissions for those nodes.

<code>
    boolean exportGPIO() {
        try {
            DataOutputStream os = new DataOutputStream(mProcess.getOutputStream());
            for (int port: ledPorts) {
                os.writeBytes("echo " +  port + " > /sys/class/gpio/export\n");
                os.writeBytes("chmod 666 /sys/class/gpio/gpio" + port + "/direction\n");
                os.writeBytes("echo out > /sys/class/gpio/gpio" + port + "/direction\n");
                os.writeBytes("chmod 666 /sys/class/gpio/gpio" + port + "/value\n");
            }
            os.flush();
        } catch (IOException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
            return false;
        }

        return true;
    }
</code>

Korean: wiringPi의 "/dev/mem"을 open 하여 mmap을 사용하는 방식으로 만들려고 하였으니 "/dev/mem"은 root가 아니면 접근을 제한하도록 되어 있어서 불가능합니다.
jni의 library에는 root 권한을 줄 방법이 없습니다.

English: It was impossible to access the /dev/mem in the Android platform because only root can access it.
There is no way to add a root permission to the JNI library.


//**Let's display and access the GPIO**//

This function runs every 100msec.\\
It reads the ADC value and update the GUI as well as LED level meter.\\
The CdS optical sensor is connected to the ADC.\\
<code>
    public void update() {
        int i = 0;
        int adcValue = 0;
        int ledPos = 0;
        if ((adcValue = analogRead (PORT_ADC1)) > 0) {
            ledPos = (adcValue * ledPorts.length * 1000) / 1024;
            ledPos = (ledPorts.length - (ledPos / 1000));
            mADC.setProgress(adcValue);
        } else
            ledPos = 0;

        for (i = 0; i < ledPorts.length; i++) {
            digitalWrite (ledPorts[i], 0);
            mLeds.get(i).setChecked(false);
        }

        for (i = 0; i < ledPos; i++) {
            digitalWrite (ledPorts[i], 1);
            mLeds.get(i).setChecked(true);
        }

        if (!mStop)
            handler.postDelayed(runnable, 100);
    }
</code>

Note that wiringPiSetupSys() should be called once to initialize the wiringPi library.