The tmote has a cc2420 (packet based) radio. All incoming data that comes into the radio gets buffered by the radio hardware before notifying the microprocessor that a packet has been received. Once a full packet has been received, an interrupt is generated and the packet is read into the memory of the MCU over an SPI interface. Using standard TinyOS components, the packet read in over the SPI is passed up to an Active message layer, followed by dispatch to the proper receive handler in the application (indexed by the active message type). To "stream" data from the radio to the serial line (i.e. the USB interface), you would have to take the message passed to the application and then send it over USB down a similar active message stack built for the serial interface. In summary, you have to go up one active message stack and then down another in order to "stream" your data packets using standard TinyOS components.
Using non-standard components (i.e. those you would have to write yourself) there is nothing preventing you from writing a component that streams the data more efficiently. Given the way the radio hardware buffers its packets, you would have to write a component that basically takes the data read over the SPI bus and pass it directly to the lower level components of the serial stack that implement the T2 serial protocol (the packet structure changes slightly, adding escape characters, etc.). Start with looking at how the two stacks are implemented: radio - tinyos-2.x/tos/chips/cc2420, serial stack - tinyos-2.x/tos/lib/serial Kevin On Nov 24, 2007 12:05 PM, Bhavish Aggarwal <[EMAIL PROTECTED]> wrote: > Hi, > > I want to stream voice from one computer to another over tmotes > connected to either comp over usb. I couldn't find a way to send > streams over the radio. How can I achieve this? Would I have to put > the data in the mote memory first or is there a way to stream directly > from the usb to radio. > > I would really appreciate some help on this issue. > > Thanks, > > Bhavish > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > -- ~Kevin _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
