Serial port data transmission

[awneil]

@awneil

It really shouldn’t be necessary to use hardware flow control at all with any form of XMODEM, since XMODEM is inherently “self-paced” - ie, the sender cannot send the next block until the receiver has indicated that it is ready by acknowledging the previous block.

Unfortunately, Wavecom have not taken advantage of this to pause the transfer while the module is doing a flash block erase.

This does appear to be fixed now: I’ve just successfully updated a WMP100 from R73a to R74a and then to R7.46 using just a 3-wire link - ie, no flow control (other than the inherent pacing of the XMODEM protocol itself).

However, I would still prefer to use harware flow control if at all possible - “belt and braces”