Ralph Corderoy wrote: [...]
Or baud rate? You could be right on the level-shifting. Any clue from peering inside?
The socket's on the back of the main board, which means all the traces are hidden between the main board and the other board, so I haven't managed to figure out what it's connected to. The baud rate seems to be 9600, because it doesn't respond on anything else. I'll try hooking up a voltmeter and seeing what the E1's TX is producing. If it does need level shifting then it obviously doesn't want inverting as well, because it *is* responding to 0x1b.
Hopefully I haven't managed to damage something connected RS232-level signals to it...