ScratchDuino-Blockly - development environment, allowing you to control your ScratchDuino robot right from your web browser using Blockly programming language.
Before we get started, you should follow some simple steps to install necessary software:
- Download and install robot drivers for Arduino (if they are didnt installed yet).
- Download and run installer Scratchduino-Blockly.
- Click on ScratchDuino-Blockly shortcut on your desktop.
- Download archive ScratchDuino-Blockly_x??.tar.gz (depending on your system type (32 or 64 bit))
- Unpack it (tar -xzvf ScratchDuino-Blockly_x??.tar.gz)
- Open folder ScratchDuino-Blockly_x?? and execute run.sh
- Download disc image ScratchDuino-Blockly.dmg and mount it (double-clicking on it)
- In opened folder execute run.command (using double-click)
Main workspace contains 5 basic parts:
- "Program" tab. Program editor, in which you can create robot-controlling algorithms using Blockly`s blocks.
- "Scene". Living area for virtual robot.
- Control panel. Contains buttons for setting up and running robot and it`s controlling program.
- Sensor panel. Reflects values from robot`s sensors during execution.
- Menu. You can use it for saving/loading your programs and, also, to choose interface language.
After the following installation steps ScratchDuino-Blockly should open in your default browser. You can open it in other browser just by copy-pasting address from address bar and hitting Enter. Now you can start programming!
First, you should make sure that your Scratchduino robot is on and correctly installed (this is needed only if you want to use real robot). To do this, connect your robot to computer using USB-cable or Bluetooth, and then click the grey button says "Port is not chosen". List of COM-ports available on your computer should appear (It may contain more than one port):
After selecting port, click "Run" button. If selected port is not the one robot is connected, there are warning should appear:
In that case, repeat all previous actions, but select another port. If selection was made right, no warnings appear, and values from robot sensors at the Sensor panel should start changing. Now you can stop executing using "Stop execution" button and follow to the next step.
Blockly is very similar to Scratch - programs also made from blocks, each representing some action or operation. It has blocks for controlling robot`s engine, getting data from sensors, creating cycles, if-then-else operators, math operations etc. But Blockly has some particular qualities that must be considered during programming:
- Block`s order matters! Blocks are executing consequentially top-to-bottom, so, for example, you should program button event handlers primarily.
- Control signal to robot engine discards effect of previous such signal so you should make cycles, conditional operators and, especially, their combinations very carefully.
- Block "while program is running" cyclically repeats action placed inside until user press stop button. User must ensure that actions inside this block don`t interrupt other robot controlling signal inside a program.
Sprite repeats movements of real robot in the "Scene" area. You can use it to debug your algorithms in the absence of real Scratchduino. In case of crossing the borser of scene, sprite appears at the other side, so, you can`t "lose" it.
Create simple program, shown on the picture:
Click "Run" button and if port was selected right, robot will drive along square. Note that sprite repeated all the movements after real robot. In case that Scratchduino does not connected, you will see a warning and program will be executed only for sprite.
You can control execution of a program using "Run", "Stop execution" and "Port is not chosen" buttons. We described port selecting button in previous sections. After the execution of program, all blocks at "Program" area will be executed once, after that, program will either finish remaining cycles (if exists), or finish the execution and will just continue updating sensor values. You can determine if program is runnning by green color of "Run" button. After changing the program, you should re-run execution(it does not necessarily to stop process using "Stop execution"). "Stop execution" button interrupts execution of program and stops robot, so, you can use it for force stop.
"Program" in the top right corner gives you the ability to save sketches (Blockly programs) on your local computer in ".blocks" extencion and load previously saved programs. "New" button will clear current editor window, advising you to save current sketch first.
One can change sensors update speed manualy in the code:
/public/scripts/global_blockly.js
line 9: global_blockly.SENSORS_REQUSET_TIMEOUT = 100;
100ms is default update timeout. Data from robot can not come faster than each 3ms. Decreasing of that parameter can cause perfomance problems, but allows better sensors accuracy.