# Understanding TotalCross for Linux ARM ## Introduction See at this guide: * Discover plugin for VS Code; * Getting your Hello World App cooler; * How to deploy; * After basics; ## Requirements Complete the Getting Started: {% content-ref url="../get-started" %} [get-started](https://learn.totalcross.com/master/documentation/get-started) {% endcontent-ref %} The following electronic components are also required: * Raspberry Pi 3; * 7x jumpers male-female; * Protoboard; * LED RGB module (or common 4 pins LED RGB); * Push-button module (or common push-button). In order to execute Gpiod methods at your embedded device, you will also need to have the libgpiod-dev package installed in your board. You can do that by entering the following command at the device's terminal: ```java $ sudo apt-get install libgpiod-dev ``` ## **Guide** ### Discover VS Code plugin A quick way to start using TotalCross is installing the [TotalCross extension for VS Code](https://marketplace.visualstudio.com/items?itemName=Italo.totalcross). **Step 1:** open VS Code console (CTRL + Shift + P) and type TotalC… autocomplete should help! ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-Lun83v5b4ERDVyE7VT-%2F3%5B1%5D.gif?alt=media\&token=7d6dd1d4-7cef-4980-af61-7752fb0805c0) **Step 2:** select *TotalCross: Create new Project;* **Step 3:** create a folder called *HelloWorld* and select it; **Step 4:** *GroupId* will be `com.totalcross`; **Step 5:** *ArtifactId* will be `HelloWorld`*;* **Step 6:** select the latest version of TotalCross SDK and `-linux-arm` platform; ![Click to expand](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-Lun8cZb1egyD-mqZBhj%2F4%5B1%5D.gif?alt=media\&token=a47a9232-5721-46c0-898e-3b494a8abb27) **Step 7:** open`RunHelloWorldApplication.java` and click *Run* (IDE). The result should be: ![Click to expand](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-Lun9-JBKRLqV_24--Q4%2F5%5B1%5D.gif?alt=media\&token=dd1ae1f0-1174-43f5-b39f-7ae41c883b17) **Step 8:** watch the integrated simulator! ### Getting your Hello World App even more Cooler :cold\_face: :sweat\_smile: The following project deals with the control of an RGB LED with user interface buttons and a pin reset button! ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LzgpB3yjx44V1Oh-Uxv%2F-LzgpT8LCC3-7z58c_wO%2Fgpiotutorial.jpg?alt=media\&token=0c630b81-2f63-4952-abda-91000f10a1b6) **Step 1:** follow the schematic: ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LzcfBCrkAb7vk8QOHul%2F-Lzcj5bEWsjwrkCoCK58%2Funderstanding_linux_arm.png?alt=media\&token=0f98176c-0c62-4d95-a2a8-682d7ef56d8c) **Step 2:** to work with pin logic after `public class HelloWorld extends MainWindow {` add: ```java // Integers to store pin numbers private int R = 4, G = 17, B = 27, pushButton = 18; // Integers to store state of each LED pin, 0 (LOW) and 1 (HIGH) private int sttR, sttG, sttB; // Buttons to control colors private Button btnR, btnG, btnB; ``` {% hint style="danger" %} If you need to work with different pinouts check the manufacturer manual! {% endhint %} **Step 3:** at *HelloWorld.java* in `initUI()` code add: ```java // Label helloWorld made on project creation Label helloWorld = new Label("Hello World!"); // Change the position of label on the Y axis, with TOP (beginning of Y) + a fill of 20 add(helloWorld, CENTER, TOP + 20); ``` **Step 4:** then, board setup: ```java // Board Setup GpiodChip gpioChip = GpiodChip.open(0); GpiodLine pinR = gpioChip.line(R); GpiodLine pinG = gpioChip.line(G); GpiodLine pinB = gpioChip.line(B); GpiodLine pinPushButton = gpioChip.line(pushButton); ``` **Step 5:** pins setup: ```java // Set LED pins as outputs and default value sttX pinR.requestOutput("CONSUMER",sttR); pinG.requestOutput("CONSUMER",sttG); pinB.requestOutput("CONSUMER",sttB); // Set Reset pin as input pinPushButton.requestInput("CONSUMER"); ``` **Step 6:** the red button: ```java // The TotalCross button: btnR = new Button("R"); // Button instantiation // without text btnR.setBackColor(Color.RED); // Set background color (red) btnR.addPressListener(new PressListener() { // Press event listener @Override public void controlPressed(ControlEvent controlEvent) { sttR = 1 - sttR; // Invert pin state pinR.setValue(sttR); // Set value (HIGH or LOW) } }); add(btnR, CENTER - 70, AFTER + 40); // To make horizontally aligned // buttons in the 'RGB' sequence, // take the center reference and // decrease 70 to place the // leftmost R. In the Y axis just // take the reference of the // previous component and add 40 ``` **Step 7:** and the other buttons: ```java btnG = new Button("G"); btnG.setBackColor(Color.GREEN); btnG.addPressListener(new PressListener() { @Override public void controlPressed(ControlEvent controlEvent) { sttG = 1 - sttG; // Pay attention to change pin!!! pinG.setValue(sttG); } }); add(btnG, CENTER, SAME); // The green button will be // placed at the center and in // the same line of previous // button btnB = new Button("B"); btnB.setBackColor(Color.BLUE); btnB.addPressListener(new PressListener() { @Override public void controlPressed(ControlEvent controlEvent) { sttB = 1 - sttB; // Pay attention to change pin!!! pinB.setValue(sttB); } }); add(btnB, CENTER + 70, SAME); // The last button will be placed // to the right of the center. ``` **Step 8:** finally we use a thread to check the state of the reset button: ```java // A thread will be used to check every 20 ms, if the reset button has been pressed: if yes then // the pin state goes to LOW new Thread() { @Override public void run() { while(true){ if(pinPushButton.getValue() == 1) { sttG = 1 - sttG; sttR = 1 - sttR; sttB = 1 - sttB; pinR.setValue(sttR); pinG.setValue(sttG); pinB.setValue(sttB); } Vm.sleep(100); } } }.start(); ``` **Step 9:** run *RunHelloWorldApplication.java* again and watch the results! ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-LunDOEt3v1aVNDLqxjG%2F6%5B1%5D.gif?alt=media\&token=2ede5627-276c-4eee-a215-05f53b400fac) {% hint style="info" %} View fully code [here](https://gist.github.com/acmlira/e6c18f0a82688f750c1648af4d101344) {% endhint %} ### How to deploy **Step 1:** open VS Code console (CTRL + Shift + P) and select *TotalCross: Deploy* ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-LunDi6Z-vuOMZiz2XLo%2F7%5B1%5D.gif?alt=media\&token=3280501b-34bd-487d-be97-cc8817ba7dc3) **Step 2:** a second dialog box will appear and just fill in the board's information: ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-LunDoXYlF_oU9Y39NP7%2F8%5B1%5D.gif?alt=media\&token=358c321d-cba1-4d2b-8813-fb35f62ca043) **Step 3:** see the results in screen or VNC ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-LunDsKM3Yzmhnvpb_Ub%2F9%5B1%5D.gif?alt=media\&token=a7ca4720-d28f-4098-99ae-af500791439f) ### After basics This was the beginning of application development for TotalCross embedded systems, how about taking a look at [TCSample](https://github.com/TotalCross/TCSample) and seeing all that can be done? See dashboard made especially for Web Summit 2019: ![](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-LunFODqxapPPckKLGiW%2Fvideo.gif?alt=media\&token=6cd8e1db-a228-4348-ad91-2f3decec5f3c) ## See more Are you interested in development with embedded systems? Contact us via [Telegram](https://t.me/comunidadetotalcross)! ![Bruno Muniz, Lucas Galvanini e Pedro Lyra no WebSummit](https://1879575642-files.gitbook.io/~/files/v0/b/gitbook-legacy-files/o/assets%2F-L_mPP3a_E_A7NbRMq7Q%2F-LumnOTtg2X_vYInc3Vo%2F-LunDx-hDEZniSPFP55o%2Fimg3%5B1%5D.jpeg?alt=media\&token=70616025-91c2-4db5-9724-665f992d0b7a) ## References * [Fritzing ](https://fritzing.org/home/)