Hi All, After posting the message for few days, I haven't got any response other than this one from Anton. Based on his message, it seems that TinyOS is causing some significant energy use during the sleep mode. Can any of the TinyOS designers answer our questions? We are in urgent need to lower the energy consumption because it is stopping our product rollout.
Thank you very much! Elliot ---------- Forwarded message ---------- From: Anton <[EMAIL PROTECTED]> Date: Mon, Oct 13, 2008 at 3:08 PM Subject: Re: [Tinyos-help] Urgent help needed about energy saving under TinyOS To: elliot chen <[EMAIL PROTECTED]> Hi, in response to some of your questions: 1) 75uA is only for MSP430, but since there are other components, I think even in the sleep mode the current consumption is greater. 2) I have measured the current consumption of a TelosB module when nothing runs on it except TinyOS (I mean there is no user program, and after Boot.booted() is signaled nothing follows) and I saw that most of the time the current is close to zero but every 2 seconds a 15 mA current pike appears, and the width of this pike is around 80 uS. I guess this pike corresponded to the OS maintenance you mentioned. Since the voltage in my TelosB was around 2.8V, the energy consumption during this pike cam be roughly estimated as 2.8V*0.0015A*0.00008s = 0.000000336 J i.e. 0.336 micro joules. 3) I think you cannot enlarge it, since 2 seconds correspond to the "from zero-to-overflow" time of the 16-bit timer driven by 32768 kHz oscillator. I don't know how it is used by TinyOS, but obviously it uses the maximum possible time interval. And of course in the sleep mode it is not possible to use "software-enlarged" timers, since they require CPU operation. May be the timer can be put into Up/Down Mode, in which according to the documentation "The period is twice the value in TACCR0". 4) don't know 5) dont' know Now I measure the current consumption of wireless modules in different circumstances. If I find something interesting I'll inform you. Anton. elliot chen wrote: > Hi All, > > We are a company focused on WSN products development in China. We have > developed a product based on TinyOS 2.X, now we are having a problem related > to the power management. Here is a brief description of the problem. > Hopefully we can get some help from you. > > 1. According to the document, TinyOS will go into sleep state when there is > no task in the task queue. As we are using MP430 MPU, even in the LPM0 mode, > it should be 75uA, but what we found out is about 200uA. > 2. We found that in the sleep state, TinyOS still wakeup at every 2 second > and do some operating system related maintenance. We don't know whether the > power was used by these maintenances. > 3. Can we enlarge the 2 seconds interval to save more energy? > 4. Can we simplify the maintenance tasks? > 5. What is the preferred approach for the power management? We need to > reach 20uA level to get the required battery life. > > Thanks in advance, > > Best, > > Elliot > > Mambo Technologies Inc. > (01186)431-85153859 > > ------------------------------------------------------------------------ > > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > -- 陈毓华 曼博科技有限公司 Elliot Chen Mambo Technologies Inc.
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