First experiment with board based on a microcontroller

Learn how to run an experiment and interact with the boards using the command line interface (CLI tools).

Access to the SSH frontend

The SSH frontend has all the tools and compilation toolchains already installed. They are also the place from where you can interact with the nodes.

You need to Configure your SSH Access if it’s not already done.

Let’s connect to the SSH frontend to use the CLI tools from there, by replacing <login> with your IoT-LAB login:

ssh <login>@grenoble.iot-lab.info

If you never used the CLI tools from this SSH frontend, you need to store your credentials with the following command:

iotlab-auth -u <login>

Thus, you won’t need to specify your login and password at each call to CLI tools.

Submit the experiment

First, download the firmware you will use for the experiment:

wget https://iot-lab.github.io/assets/firmwares/tutorial_m3.elf .

Then submit a 20-minutes experiment, named first_exp, using 2 IoT-LAB M3 nodes (m3:at86rf231) from the grenoble site, which will run the tutorial_m3.elf firmware:

iotlab-experiment submit -n first-exp -d 20 -l 2,archi=m3:at86rf231+site=grenoble,tutorial_m3.elf

Wait until the experiment’s state is Running

iotlab-experiment wait

You can note here that we have submitted an experiment by directly associating the firmware. It is also possible to submit the experiment without firmware and to flash the firmware on the nodes in a second step with the $iotlab-node --update tutorial_m3.elf command.

Interact with the nodes

Get the nodes list assigned to your experiment by the scheduler:

iotlab-experiment get -n
{
    "items": [
        {
            "archi": "m3:at86rf231",
            "camera": null,
            "mobile": "0",
            "mobility_type": " ",
            "network_address": "m3-101.grenoble.iot-lab.info",
            "production": "YES",
            "site": "grenoble",
            "state": "Alive",
            "uid": "9181",
            "x": "0.40",
            "y": "24.63",
            "z": "-0.04"
        },
        {
            "archi": "m3:at86rf231",
            "camera": null,
            "mobile": "0",
            "mobility_type": " ",
            "network_address": "m3-102.grenoble.iot-lab.info",
            "production": "YES",
            "site": "grenoble",
            "state": "Alive",
            "uid": "a881",
            "x": "1.00",
            "y": "24.63",
            "z": "-0.04"
        }
    ]
}

The node’s serial port link (i.e. UART) is forwarded onto the SSH frontend via TCP socket on port 20000. The netcat utility (nc) let you connect to a TCP socket and read/write from/to it.

Run the nc command replacing <id> with a value picked from your nodes list:

nc m3-<id1> 20000

The firmware is waiting for reading characters to its serial link to do respectives actions.

Here is its help:

IoT-LAB Simple Demo program
Type command
    h:	print this help
    t:	temperature measure
    l:	luminosity measure
    p:	pressure measure
    u:	print node uid
    d:	read current date using control_node
    s:	send a radio packet
    b:	send a big radio packet
    e:	toggle leds blinking
cmd>

Test some actions by typing the corresponding character then Enter.

If you want to see reception of radio packet by the second node, open a second terminal, and run this set of commands:

ssh <login>@grenoble.iot-lab.info
nc m3-<id2> 20000

Go Further

• Consult the CLI documentation.
• Learn how to aggregate all the serial port links of your nodes with the Serial aggregator tool.