Monitor the consumption of M3 node during an experiment

 

Difficulty: Medium

Duration: 20 minutes

Prerequisites: Configure SSH Access / Submit an experiment with M3 nodes using the web portal

Description: Each node of an experiment is managed by its Control Node (users have no access to it), that interacts passively or actively. It monitors node consumption, power radio signal (RSSI) and selects power supply (battery or DC through POE). A Profile represents the Control Node configuration during the experiment. The aim of this tutorial is to create a profile for monitoring consumption and launch an experiment with a firmware that turns on/off red, blue and green LEDs (1Hz period)

1. Log into the Webportal
2. Select the Resources / Monitoring profiles tab
3. Click the New profile button to create a new profile
4. Set a profile Name, the M3 Node architecture, and all the Consumption checkboxes (current, voltage, power) with:
   • Period = 8244 µs
   • Average = 4
5. Save this profile.
6. This setting will give you a sampling period of P = 8.244 ms * 4 * 2 = 65.95 ms (see below for more informations about the sampling period).

   

7. Submit a new experiment
   • Duration : 10 minutes and select “As soon as possible”
   • Choose one node:
     • Select nodes “by node properties”
     • Select Archi = M3 (at86rf231) / Site = Grenoble / Quantity = 1 / Mobile = no
     • Click “Add to experiment”
   • Firmware association: use this tutorial binary firmware file. (click button Add Firmware (microship icon next to the node))
   • Monitoring profile association: use the profile you have created earlier. (click button Add monitoring (thermometer icon))

   

8. Click on the experiment in the list, and make a note of the node id, while you wait for the experiment to become running.
9. Connect to the SSH fronted of Grenoble with X11Forwarding

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

10. The consumption measure values are stored in your home folder in .oml files. As we use caching mechanism, you must wait that you have content in the file.

    <login>@grenoble:~$ less ~/.iot-lab/<experiment id>/consumption/m3-<id>.oml
    protocol: 4
    domain: 1621
    start-time: 1379945917
    sender-id: m3-3
    app-name: control_node_measures
    schema: 0 _experiment_metadata subject:string key:string value:string 
    schema: 1 control_node_measures_consumption timestamp_s:uint64 timestamp_us:uint32 power:double voltage:double current:double 
    content: text
    
    1.341009        1       1       1379945918      303436  0.053461        3.272500        0.016347
    1.341392        1       2       1379945918      307892  0.053232        3.273750        0.016270
    1.341448        1       3       1379945918      312317  0.053384        3.272500        0.016322

    See the profile measure table below for more informations.

11. Plot your file using the oml_plot.py script file

    <login>@grenoble:~$ plot_oml_consum -p -i ~/.iot-lab/<experiment id>/consumption/m3-<id>.oml

    You may observe oscillations corresponding to the 1Hz LED(s) blinking. It is also possible to measure the current on each LED which is theoretically equal to 2.4 mA.

1. Repeat the operations 3. to 7. to measure the LED consumption, changing the monitoring sample period parameters given in 4. By choosing a smaller sample period (Period = 1100 µs = 1.100 ms ; Average = 1 ; Sample Period = 1.100 * 1 * 2 = 2.200 ms), you will observe that the signal measure noise is not filtered (see figure below).