We did have the support in the CC1000 radio stack and took it out because it did not play nicely with Power Management (HPLPowerManagement). The problem is that if the timestamping uses the 4/7MHz oscillator, then the node can never be powered down in low duty cycle operations (aka the oscillator can never be turned off and the cpu run off the 32khz oscillator).
Changing from 16 to 32 bits in the internal TOSMsg format doesn't seem to be a problem. I think we need to have a more elaborate conversation about the side effects of having timestamping as a default feature in the radio stack. Adding hooks for it isn't a problem (there already are signaled events for being notified when the beginning of the packet is being sent and when it is being received). More analysis of how it affects Timers, HPLPowerManagement, and use of the oscillators is needed imho. -Joe -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeremy Elson Sent: Monday, July 14, 2003 12:58 PM To: [EMAIL PROTECTED] Subject: [Tinyos-users] Can radio stack changes be checked in? Hello, At UCLA a number of us have been working on high-precision time synchronization. We've been keeping our changes in our own repository for a long time (e.g. since tinyos 0.43) but historically it's been very difficult for us to track the newer TinyOS code as it is released. So, if possible, we'd like to check a lot of this code into sourceforge. The problem is that it makes (small) changes to the radio stack, and we're not sure if these kind of checkins are "allowed". Specifically, we'd like to put packet reception timestamping back into the stack at interrupt-time. We shoot for microsecond resolution, so would like to get the timestamps using the TimerHeap component - which constructs a virtual 32-bit timer with both high precision and long range (i.e. by combining one of the on-chip counters with a software accumulator to track how many times it has wrapped). The problem is that doing so adds a TimerHeap dependency to the basic comm stack. We'd also like to change the timestamp field of TOS_Msg from 16 to 32 bits, but this changes the packet format. (Just the internally used format, though, hopefully not the over-the-air format.) Cheers, UCLA Tinyos Folks _______________________________________________ Tinyos-users mailing list [EMAIL PROTECTED] http://mail.Millennium.Berkeley.EDU/mailman/listinfo/tinyos-users _______________________________________________ Tinyos-users mailing list [EMAIL PROTECTED] http://mail.Millennium.Berkeley.EDU/mailman/listinfo/tinyos-users
