readme

MANTIS是由科罗拉多大学开发的传感器网络嵌入式操作系统。 这是mantis的0.9.5版本的源码。

README for pwrmgt.c

This is a small sample program that demonstrates the mos_thread_sleep(time)
function and the power management capability. They are related. In a single 
threaded system, mos_thread_sleep(time) would be functionally equivalent, 
that is, the MCU enters power-save mode when a thread calls mos_thread_sleep.
Since Mantis OS (mos) is a multithreaded system, mos_thread_sleep() works ala
unix sleep. The thread sleeps for the specified time, the MCU enters power-save
mode only when the systems enters the idle loop (no more threads ready to 
execute). A enable_pwr_mgt() is provided becasue it makes power management 
explicit and places wake up obligations on the application. Applications may 
use mos_thread_sleep() to fulfill this obligation becasue this funtion uses 
Timer/Counter0 to wakeup the MCU. See ATmega128L manual for further details.

Usage:
/* mos_thread_sleep(x)
 * where x = 1...256
 * for example:
 *       x = 1 = sleep for 0.03125 secs. or 31.25 ms
 *       x = 2 = sleep for 0.0625  secs  or 62.5 ms
 *       x = 3 = sleep for 0.09375  secs  or 93.75 ms
 *       .
 *       .
 *       .
 *       x = 32 = sleep for 1 sec
 *       .
 *       .
 *       .
 *       x = 64 = sleep for 2 secs.
 *       x = 128 = sleep for 4 secs.
 *       x = 256 = sleep for 8 secs.
 */

This small application can be used to test mos_thread_sleep and pwr mgt by
minor changes to the application. However, the nodes must be instrumented 
to verify pwr mgt. Although exhaustive testing is impractical, I have verified
that the code works for nymphs and mica2s. Also, I tired different time 
durations for multiple threads to verify that the threads are scheduled 
correctly. 

Most of the related code is in mantis/src/mos/arch/avrn the following files:
msched.c/msched.h, timer.c/timer.h and tlist.c/tlist.h.