[Tinyos-devel] serial communication in TinyOS2

[Razvan Musaloiu-E.]

Hi!

I'm trying to use the serial communication from TinyOS2 and I encounter
some difficulties.

First: even the description of sfsend in README says:

	- sfsend: send a packet (specified on the command line) to a serial forwarder

the code doesn't really do this. It tries to send some packets but they
are composed manually. The way it is done is like this:

    26        unsigned char packet[100];
    27
    28        packet[i++] = 0xff; // addr low byte
    29        packet[i++] = 0xff; // addr high byte
    30        packet[i++] = 0x04; // AM id
    31        packet[i++] = 0xbc; // group id
    32        lenp = i++;         // length
    33        packet[i++] = j;    // payload
    34        packet[i++] = 0xbe; // payload
    35        packet[i++] = 0xef; // payload
    36
    37        packet[lenp] = i-5; // length, don't include header

This doesn't seem to follow the format described in
tinyos-2.x/tos/lib/serial/Serial.h which is:

   112  typedef nx_struct serial_header {
   113    nx_am_addr_t addr;
   114    nx_uint8_t length;
   115    nx_am_group_t group;
   116    nx_am_id_t type;
   117  } serial_header_t;

Could someone provide some guidance here? :-)

Second: I find very tempting to use Python to talk to a serial forwarder
but the code from tinyos-2.x/support/sdk/python doesn't have any
utilization instructions. :-) I manage find how I can connect to a serial
forwarder (sending "U ") and what is the format of the received data
(one byte size follow by the packet) but I still don't know how to
use the Message class in a useful way. Could someone make a little light
here? :-)

Thank you!
Razvan ME