Robot App Store Developer Program How to Make Lego NXT to Play a Sound Make sure you are familiar with "What is a Lego NXT Bluetooth Telegram" chapter before you continue to this How to play a sound on the NXT: PlayTone command- Start a playback of a MIDI tone specified by frequency in Hz and duration is milliseconds; PlaySoundFile command- Start a playback of a specified existing RSO file. You can either download a file to the NXT’s brick using Bluetooth, or you can use a file handling commands to transfer the file from your device programmatically; Use the StopSoundPlayback command to stop the playback. In case of playing the sound file in a loop (or if you just want to stop the playing This command is valid for both PlayTone and PlaySoundFile; Sound play command types Sound play commands are part of the "Direct commands". There are two relevant command types for a direct command: 0x00 for a command with reply message, and
0x80 for a command without the reply message. Sound file name format consists from: [name, up to 15 ASCII characters].rso[string NULL terminator 0x00]. The system is case insensitive, meaning uppercase characters are treated the same as lower case characters. Frequency to note mapper Lego NXT Programming Over Bluetooth Frequency Note Mapper This command is used to play a MIDI tone specified by frequency in Hz, and duration is milliseconds. The playback won’t be stopped as the program/ robot-app is finished. Use the StopSoundPlayback command to interrupt the playing process earlier.[0x03] [Frequency byte LSB] [Frequency byte MSB] [Duration byte LSB] [Duration byte MSB] Byte 0-1: Command length LSB first. Byte 2: Command type- direct command. Since no error will be retrieved in any case, we can’t find a reason to ask for a response message, therefore, use always the 0x80 as a command type. If, for some reason, you are of those who just can’t live without unnecessary messages from the robot,
in this case use the 0x00 as a command type. Byte 3: Command- play a sound. Byte 4-5: Frequency for the tone in Hz. Make sure the value range is 200-1400. There is no error message if the value is out of range. Take a look at the “Frequency to note mapper” chart above to choose the relevant note. Make sure to round the Hz number when you send the value. Byte 6-7: Duration of the tone is milliseconds. The reply message that is coming back (if requested) will always look like: Byte 0-1: Message length LSB first. Byte 2: Command type- reply message Byte 3: Command that has requested for this reply. Byte 4: Command status- 0x00 for success or a theoretic error number for failure. This command will not retrieve an error in any case. Let’s play a Mi (C in the mapping chart) sound for half a second. The command that is sent to NXT is: 0x06 0x00 0x00 0x03 0x0B 0x02 0xF4 0x01 The command that is received from NXT as a reply is:
0x03 0x00 0x02 0x03 0x00 This command is used to play a specified existing RSO file. Make sure you use a valid rso file. The system will not notify in case of existing file from a different type.[0x02] [0x00 or 0x01] [fileName.rso] For direct command with response message use 0x00, otherwise, for direct command without the reply message, use 0x80. Byte 3: Command- play a sound file. Byte 4: Play in a loop. For playing the sound file only once use 0x0, otherwise, for playing the sound file indefinitely use 0x01. Byte 5-24: Sound file name, including its extension- rso. The system is case insensitive. The bytes of file name and type characters should be ASCII encoded. NULL terminator must appear at the end ('\0'). In case the name of the file is shorter than 15 characters, NULL terminator byte should be added to the end of the file name extension for each missing character. Total file name characters, including the NULL terminators, should always be 20.
The reply message that is coming back (if requested) looks like:[0x02] [0x02] [0x00 or error] Byte 4: Command status- 0x00 for success or error number for failure. NXT File Handling over Bluetooth- Introduction chapter for error numbers. Play the Woops.rso sound file only once. 0x17 0x00 0x00 0x02 0x00 woops.rso\0\0\0\0\0\0\0\0\0\0\0 0x03 0x00 0x02 0x02 0x00 This command is used to stop the playback for both PlayTone and PlaySoundFile commands. Byte 3: Command- stop the sound. PlayTone command has been sent with a very long duration, or PlaySoundFile command has requested a playback to be in a loop. In order to stop the playback, StopSoundPlayback command is being sent. 0x02 0x00 0x00 0x0C 0x03 0x00 0x02 0x0C 0x00 Let's move forward and learn how to program a pre-defined text to speech. Lego NXT Mindstorms Driver - Android app Do you have Lego NXT Mindstorms and an Android smart phone? Why limiting yourself to the desktop?
Unleash your NXT, and control it from literally any... Lego NXT Face Tracker - Android app Make your LEGO NXT Mindstorms to follow your face! Who said LEGO NXT Mindstorms doesn’t have a camera? Upgrade your Lego vehicle to follow your fa...THIS PROJECT HAS MOVED TO GITHUB Please visit the new location at All source, releases, and issues have been moved. This CodePlex project will no longer be maintained or viewed by the maintainers. Please move to the new location. Getting Started Pairing the Brick References Creating a Brick Object Events and Ports Connecting to the Brick Direct, System, and Batch Commands Motors Sensors System Commands Batch Commands WinRT Permissions Phone Permissions More Information Known Issues Please note that this library requires firmware v1.03H or higher to be installed on the brick. You can install this firmware with the LEGO MINDSTORMS desktop software from the Tools -> Firmware Update menu item. This project contains libraries for Windows desktop (WinForms, WPF, Console, etc.), Windows Phone 8, and WinRT (Windows 8.1 and higher).
You will also find several tester and sample applications that demonstrate the library in action and how to use it in yourIn addition, here are some quick examples to get you started... The LEGO EV3 brick can be connected via USB (except for Windows Phone), Bluetooth or WiFi. To enable Bluetooth on the brick, navigate to the Settings tab (the wrench icon) and select Bluetooth. Make sure the Visibility and Bluetooth items are both checked as shown: The pairing process via Bluetooth will be different with each platform. In summary, you will need to open your Bluetooth settings, search for devices, find the one named EV3, pair, entering the code 1234 when prompted, and the devices should pair. WiFi is not built in to the EV3 brick. The only adapter that is compatible and supported is the NETGEAR N150 USB device (WNA1100), which can be plugged into the USB port on the side of the brick. You can also configure WiFi by opening the desktop MINDSTORMS software, starting a project, and configuring by clicking on the wrench icon in the lower right of the screen, selecting your access point, clicking the Connect button, and configuring the password:
You can also do this via the brick itself from the WiFi section under the Settings tab. Once enabled and connected, you will be able to determine the brick's IP address by selecting the current connection in the list of connections on the brick. First off, you will need to set a reference to the appropriate library for the application type you're creating. You can find the library and set a reference easily using NuGet. The three libraries are named: Creating a Brick object With the reference set, you can create a Brick object and start communicating with the physical EV3 brick. However, you will also need to pass an instance of an object that implements the ICommunication interface to the Brick constructor, which will determine how the library will talk to the brick. Here are the options: BluetoothCommunication (requires the COM port the brick is hosted on while paired) UsbCommunication NetworkCommunication (requires the IP address of the brick) BluetoothCommunication NetworkCommunication (requires the IP address of the brick)
BluetoothCommunication UsbCommunication NetworkCommunication (requires the IP address of the brick) The following snippet of code will create a new Brick object communicating over USB: The Brick object contains a BrickChanged event. You can hook this event to receive a notification every time some property on the brick changes. For example, when someone presses a button on the brick face, the value of a sensor changes, a sensor/motor is added/removed, The Brick also has a dictionary collection of Port objects. These map to the physical ports on the EV3 brick. You can get the type/value/mode/etc. of anything plugged into any port at any time. Or you can use the event. You can hook the event as follows: Or, to get the value of the sensor on Port 1 at any time, just use the Ports collection: Connecting to the Brick Once the Brick is created and the event is hooked (or not), it's time to connect to the brick. This is done using theBy default, this will setup a timer which will poll the brick for data every 100 milliseconds.
If you wish to poll more quickly or slowly, you can pass in a TimeSpan object for the polling time you require. Or, to disable polling altogether, use theHere's how to connect: Direct, System, and Batch Commands There are 3 types of commands that can be sent to the brick: DirectCommand - these commands are "one off" commands and are executed immediately. These are great if you only need to do a single operation at a time, but can be very slow when calling a series of them in very quick succession. you'd want to use... BatchCommand - these commands are queued up until the SendCommandAsync method is called, at which point the entire queue is sent in a single packet and executed. SystemCommand - these commands are also "one off" but cannot be batched. These commands are for uploading files and other system-level functions. You will find these inside of the Brick object as DirectCommand, BatchCommand and SystemCommand properties, each of which contains their corresponding methods.
Up to 4 motors can be hooked up to the ABCD ports on the EV3 brick. There are a variety of methods to interact with the motors which you can find in the API documentation. As an example, here is a DirectCommand which will turn the motor on Port A for 5 seconds at 50% power: Up to 4 sensors can be hooked up to the 1234 ports on the EV3 brick. Additionally, each motor also acts as a sensor and can return positional/rotational data. Each sensor/motor may also have the ability to return its data in a variety of different modes. example, the Touch sensor can return whether the button is pressed, or it can return the number of times it has been pressed since it was last reset. To set the mode of a port, use the SetMode method as shown: Sensor data is also returned in 3 different formats: Raw, SI (International System of Units), and Percentage. In most cases, the SI value is the one you want to use: System commands can be used to upload files, delete files, etc. Here's an example to upload a sound file from your PC to a specific location on the brick:
Here is an example of a Batch command to set the speed of one motor to 50%, the power of a second motor to 50%, and play an audio tone: When creating a WinRT application which uses this library, certain capabilities must be added to the application manifest file. To do this, open the package.appxmanifest file in the XML editor and add the following to the Capabilities section, based on the type of communication you will be using (any or all can be used at once): <: =""><: =""><: ="" :> Network (note that this one CAN be set from the manifest editor UI)To do this, open the WMAppManifest.xml and add the following capabilities: ID_CAP_PROXIMITY (for BluetoothConnection) ID_CAP_NETWORKING (for NetworkConnection) Check out the Getting Started video: Launch in another window WinRT documentation is currently missing but will be provided once we can properly build it. In the mean time, refer to the Desktop and Phone documentation which is 99.9% identical.