On Fri, Jul 13, 2012 at 4:41 AM, Wei Shen <[email protected]> wrote:
> Hi Eric, > > Thanks for your answer. > > On telosb(MSP430,cc2420) platform, SFD pin of CC2420 is configured to > TimerB1 capture pin, which is hardware connection! SFD pin can be used to > capture the moment when a packet arriving. I need a 1MHz source for SFD. > This is the reason I change the clock source of TimerB1. > Is that easy to exchange the source of TimerA and TimerB? > Depends on what you mean by easy. Yes it is easy but it has ramifications that ripple through the system because the clocking and timers are pretty fundamental. if you change this (which is a good idea given your h/w constraint), you will need to understand what is effected. i'm pretty sure what you are doing has already been done but I don't remember the details. I think it will have something to do with Tmicro implementations. Try searching for that and/or searching for different 2420 implementations. eric > > Best, > Wei > > > > > > On Mon, Apr 30, 2012 at 1:12 PM, Eric Decker <[email protected]> wrote: > >> >> Before changing something so fundamental, you really need to understand >> exactly what you are doing. >> >> look at examples that are out there on how the low level hardware is >> configured.. etc. >> >> There are also h/w ramifications. >> >> On Mon, Apr 30, 2012 at 2:02 AM, Wei Shen <[email protected]> wrote: >> >>> Hi all, >>> >>> I use tinyos 2.1.1 downloaded from google code. I have changed the >>> clock source from 32khz to 1MHz of the TimerB of MSP430 in >>> tos.chips.msp430.timer. >> >> >> Why? >> >> 1st TimerB is configured to use the 32KHz clock which is 32768 and driven >> from a h/w Xtal oscillator. >> >> All of the TimerB wiring eventually leads up to providing the main Tmilli >> source. The 32KHz clock >> source is the low power clock and what is used when the mcu goes to sleep. >> >> The 32KHz clock and relationship to the main DCO clock (TimerA) is also >> managed on boot up to sync the >> DCO clock to something reasonable with respect to the 32KHz clock. >> Otherwise the DCO clock can not be >> exactly set to what is desired. >> >> The serial code uses the main DCO clock as its source so if the SMCLK >> (driven from DCOCLK) is off then >> the baud rate won't be what it needs to be. >> >> >> Msp430ClockP. In order to match this >>> modification, I have also changed all counter/timer from wiring to >>> timerB to timerA. After that, unfortunitely, the printf does not >>> work. When i use mincom to print sth, it always garbled characters. >>> >>> >>> I don't know the relationship between /tos/lib/printf and timerB or >>> 32khz. I would really appreciate it if you could help me about this >>> issue. >>> >> >> Like I said, why? >> >> >> >>> >>> Best, >>> Wei >>> >>>> >>>> -- >>>> Wei Shen >>>> PhD Student in Mid Sweden University, Sweden >>>> [email protected] >>>> >>> >>> >>> >>> -- >>> Wei Shen >>> PhD Student in Mid Sweden University, Sweden >>> [email protected] >>> >>> _______________________________________________ >>> Tinyos-help mailing list >>> [email protected] >>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>> >> >> >> >> -- >> Eric B. Decker >> Senior (over 50 :-) Researcher >> >> >> > > > -- > Wei Shen > PhD Student in Mid Sweden University, Sweden > [email protected] > -- Eric B. Decker Senior (over 50 :-) Researcher
_______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
