| NATS subscriber |
| |
| This sample code demonstrates how to write a NATS subscriber sample |
| application. |
| |
| See: http://nats.io/documentation/internals/nats-protocol/ for more |
| information about the NATS protocol. |
| |
| |
| Requirements |
| ------------ |
| |
| * Ethernet LAN for testing purposes. |
| |
| * Galileo Gen 2 Development Board. |
| |
| * USB-UART cable: CH340, FTDI 6-pin or equivalent for debugging. |
| |
| * NATS server, subscriber and publisher applications. See: |
| |
| http://nats.io/documentation/tutorials/gnatsd-install/ |
| http://nats.io/documentation/clients/nats-clients/ |
| https://github.com/nats-io/nats |
| |
| Building instructions |
| --------------------- |
| |
| * Read src/main.c, change the IP addresses according to the LAN |
| environment. |
| |
| * On a terminal window, type: |
| |
| make pristine && make |
| |
| * To load the binary into the Galileo Dev Board, follow the steps |
| indicated here: |
| |
| https://www.zephyrproject.org/doc/board/galileo.html |
| |
| |
| Usage |
| ----- |
| |
| * Follow nats.io documentation to setup the server and client |
| applications. |
| |
| * Start the NATS server: open a terminal window and type: |
| |
| gnatsd -D |
| |
| The terminal window must display something like this: |
| |
| [2045] 2016/07/27 17:40:20.928840 [INF] Starting nats-server version 0.8.2 |
| [2045] 2016/07/27 17:40:20.928913 [DBG] Go build version go1.5.4 |
| [2045] 2016/07/27 17:40:20.928922 [INF] Listening for client connections on 0.0.0.0:4222 |
| [2045] 2016/07/27 17:40:20.929035 [DBG] Server id is X6QdoKdcVHDeWQcVIpJcb5 |
| [2045] 2016/07/27 17:40:20.929048 [INF] Server is ready |
| |
| * Connect the USB-UART cable to the Galileo. Open a terminal and run: |
| |
| screen /dev/ttyUSB0 115200 |
| |
| * Connect Galileo to the LAN, Turn on the board. |
| |
| * On the screen terminal window, the following text will appear: |
| |
| WARNING: no console will be available to OS |
| error: no suitable video mode found. |
| -------------------------------- |
| -------------------------------- |
| |
| * Run the NATS publisher client. Open a terminal window and type: |
| |
| nats-pub sensors DOOR89:CLOSED |
| |
| The terminal window will display: |
| |
| Published [sensors] : 'DOOR89:CLOSED' |
| |
| * On the screen terminal window, the following message will appear: |
| |
| -------------------------------- |
| Subject: [7] sensors |
| Sid: [2] z1 |
| Reply-to: not found |
| Payload: [13] DOOR89:CLOSED |
| -------------------------------- |
| |
| |
| Final remarks |
| ------------- |
| |
| Full NATS support is not yet achieved. However, current publisher |
| and subscriber routines are enough to write basic NATS applications. |
