Introduction: Arduino 433 Transmit

  • This project will allow you to transmit a string to an Arduino 433 Receiver (which is covered in this instructable: For this transmit project you will use a scratch-like program called Arduino-Blockly and you will use male connectors to wire the project together..
  • Setup
    • Download Arduino ide from
    • Install the 340 usb driver from
    • Download RoboticsLibrary from
    • Download Blockly from
    • Place the RoboticsLibrary directory in your Arduino libraries directory
    • Place the Blockly directory on your C drive.
    • Obtain a 433 receiver transmitter pair online or from me ($5.00=>
    • Obtain a nano connected to a breadboard online or from me ($8.00=>

Step 1: Create the Blockly Diagram

From the toolbox/ArduinoSetup , drag the setup/loop block to the main canvas

From the toolbox/Logic, drag the if do to the main canvas

From the toolbox/RF drag the Send Message box to main canvas

Now assemble the pieces to perform this logic in the setup area:

Send the message "hello" on digital io pin D12. The diagram should look similar to the above picture.

Now in blockly click on Arduino "Copy to Clipboard". This will copy the arduino sketch into the clipboard

Step 2: Paste the Arduino Code to the IDE

Open the Arduino IDE and select File New to create a new sketch.

Press Cntl-A to select all the current text and then Cntl-V to paste the clipboard contents into the sketch.

You should see something like the image above. Select Sketch compile to see if the sketch compiles correctly.

If it does not compile, this is usually because the RoboticsLibrary has not been placed in the Arduino libraries directory.

To find out the location of your Arduino libraries directory, select File, Preferences in the Arduino IDE and note the sketch location. This directory should contain your sketches as well as the libraries directory. The Robotics Library from should be located there.

Once the sketch compiles, connect the Nano which you can obtain on line or from me ($8 and in Tools select the port for the nano and Board Nano. Then press upload. This will load the sketch on the nano.

To wire the transmitter, connect the data pin on the receiver to D12 on the nano, and connect + on the transmitter to 5V on the Nano and - on the transmitter to GND on the nano.

Now select tools, Serial Monitor and the sketch should show "Ready". When the receiver(which is covered in this instructable: receives the string "hello" you should see "Got a Hello" in the receiver's serial monitor.