# gr-webserver

**Repository Path**: delnano/gr-webserver

## Basic Information

- **Project Name**: gr-webserver
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: GPL-3.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2021-04-17
- **Last Updated**: 2021-04-17

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# gr-webserver

This web server emulates a terminal/console using a browser for the user interface.<br>

For use with GNU Radio, it sends keyboard input text to a ZMQ PUSH Message socket and displays received text from a ZMQ PULL Message socket. It can be used as an alternative to a Message Edit Box and/or a Message Debug Block for string messages.

Here is a screen shot:

![screen shot](./gr-webserver_out.png "gr-webserver Console")

## Installation

See [What is GNU Radio?](https://wiki.gnuradio.org/index.php/What_is_GNU_Radio%3F) and [Installing GNU Radio](https://wiki.gnuradio.org/index.php/InstallingGR)

Note: These instructions are written for a Linux OS. Similar commands work for Mac and Windows.

* Open a terminal window.
* Change to the home directory.

```
cd ~/  
```

* If you don't have 'git', enter

```
sudo apt install git  
```

* Clone the repository:

```
git clone https://github.com/duggabe/gr-webserver.git
```

* Change to the cloned directory:

```
cd ~/gr-webserver
```

* If you don't have 'node' (or 'nodejs') enter:

```
sudo apt install nodejs
```

* If you don't have 'npm' enter:

```
sudo apt install npm
```

* Install zeromq:

```
npm install zeromq --save
```

* There are three files to define the Operating System for gr-webserver. Execute the appropriate one.

```
cp -v opSys_Linux.txt opSys.txt
cp -v opSys_Mac.txt opSys.txt
copy opSys_Win.txt opSys.txt /v
```

## Operation

* To start the webserver, enter:<br>
  `node index.js` <- OR -> `npm start`<br>
  Note: using npm is slower to start, but it sets up some error logging of its own which can be useful in debugging problems.
* You will get the following messages on your terminal:
    - "opSys is Linux" (your appropriate OS)
    - "gr-webserver has started. Listening on port: 50250"
* A web page (or tab) will open in your default browser.
* Text entered in the "Input" field is processed one line at a time. The terminator is the 'Enter' key. The text will be displayed on the Console screen, preceded by<br> &quot;&gt;&nbsp;&quot;, and will be sent through a ZMQ PUSH Message port 50251.
* Text received by the ZMQ PULL Message port 50252 will be displayed on the Console screen, preceded by &quot;&lt;&nbsp;&quot;.
* The terminal will remain attached to the node.js process.
* Any additional informational messages written to the console will appear there.
* To terminate, close the tab in your browser and enter Control-C on your terminal.

## Using across multiple computers (new in version 1.0.16)

If the ZMQ Message Source and Sink blocks are on different computers on the same LAN, then the IP and port number of the ZMQ PUSH Message Sink block must be specified on each end of that connection. For example, if the Sink is on IP 192.168.2.14:50251 and the Source is on IP 192.168.2.5, both Source and Sink blocks must specify the Sink IP and port (192.168.2.14:50251).

* To set the local and remote IP addresses, start the webserver with IP parameters (local remote). For example:

```
node index.js 192.168.2.14 192.168.2.5
```

* See [ZMQ PUSH Message Sink](https://wiki.gnuradio.org/index.php/ZMQ_PUSH_Message_Sink) for additional information.

## QA / Testing

* In the examples folder, there is an echo program which will receive messages, capitalize the text, and return the message. To use it while gr-webserver is running, open a second terminal screen and perform the following steps:

```
cd ~/gr-webserver/examples
python3 zmq_PUSH_PULL_server.py
```

* Whatever you type on the Input will be echoed in all caps.
* There is also an example flowgraph which will display input messages on the console and send out a "Testing" message every 10 seconds.

* While gr-webserver is running, you can open another tab in your browser to ```http://localhost:50250/trace``` to see some additional information.