synctemp
This section refers to the following sample application:
04-synctemp
Running the Application
The 04-synctemp sample application showcases the network-wide synchronization of a
SmartMesh IP
network allowing you to capture temperature measurements across a network synchronized to within a few milliseconds. It works in concert with the SyncTemp command-line application (part of the SmartMesh SDK), which logs the data. The SyncTemp directory also includes logAnalysis.py, which will calculate some statistics about the temperature data timing.Load the 04-synctemp sample application on multiple motes - wait for them to join the same network and they will begin to take temperature measurements in synchrony.
While nodes in a
SmartMesh IP
network are synchronized to within a handful of micro-seconds, the precision of the uC/OS-II timers limits the accuracy of the temperature measurement synchronization to a handful of milliseconds.
Implementation Details
The sample application consists of a task which arms a timer, waits for it to expire, then takes a temperature measurement and sends it to the manager.
It uses dn_getNetworkTime() to retrieve the current network time, and arms the timer so it expires at the integer second closest to the reporting period. Since all nodes increment their ASN and UTC time at the same time, this event happens at the same time on all nodes in the network.
It also contains CLI commands for getting and setting the sample period, and supports setting the period over the air.