[uracoli-devel] radio_set_state(): how long to wait?

[Joerg Wunsch]

I'm trying to use the high-level radio interface.

Right now, I'm running into a situation where radio_error() is called,
because the state transition is not completed within the expected
time.  The expected state is TX_ARET_ON (25), but the current state is
BUSY_TX_ARET (18).  The code where this happens is:

    retries = 140;              /* enough to await an ongoing frame
                                 * reception */
    do
    {
        currstatus = trx_bit_read(SR_TRX_STATUS);
        if (expstatus == currstatus)
        {
            break;
        }
        /** @todo must wait longer for 790/868/900 MHz radios */
        DELAY_US(32);
    }
    while (retries--);

Note the @todo (I'm working in 868 MHz where things are slow), but the
key point here is: this is a TX_ARET transaction, which can take
*much* longer to complete (in particular in case of a busy channel, or
a peer that doesn't respond at the first attempt).

So the big question is: How long to wait here?  Perhaps it's better to
wait indefinitely while the current status is one of the BUSY_*
states?  At least, for BUSY_TX_ARET, I could not imagine of a way to
precalculate a max wait time.

(Btw., the requested state transition is the automatic one that
attempts to put the radio into the configured "idle_state" after a
transmission.)

-- 
cheers, J"org               .-.-.   --... ...--   -.. .  DL8DTL

http://www.sax.de/~joerg/                        NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)