ttyACM0 - used by pppd to create a data connection.
ttyACM1 - odd serial output; has some extra framing?
ttyACM2 - No observed output.
ttyACM3 - Usable by application.
ttyACM4 - No observed output.
ttyACM5 - No observed output.
ttyACM6 - No observed output.
I see there is a ‘AT+KUSBCOMP’ which configures the endpoints. I want to know what the endpoints are mapped to. Ie, it seems that the first and fourth are a typical serial interface in ‘AT’ mode. The second endpoint seems to have some extra framing. Are the others configurable somehow or is the mapping hardcoded? I guess some are a trace interface (maybe this is EP1).
If this is in the documents somewhere, thanks for pointing me to them. I am not 100% familiar with the Sierra product line and I don’t know what of (HiLo, etc) might refer be applicable to the HL8548.
Yes, you are right, ttyACM0/3 are applicable for AT/PPP/NMEA, while other interfaces are reserved and trace taking (e.g. ttyACM1/2)
The assigned functions are fixed for each interfaces but there are two set of configurations:
+KUSBCOMP mode 1 - the 7 ACM as you observed
+KUSBCOMP mode 2 - 3 ACM (ttyACM0 - AT/PPP/NMEA, ttyACM1/2 - trace) + 3 ECM
I read the "Firmware update’’ and there are some special protocols for USB. Is this a seperate (non ACM USB mode) or is the protocol just over an existing USB/COM port, but the protocol can have less framing inside the virtual channel? Our hardware teams wants to eliminate pin UART pins to the main CPU for pin constraints. I just want to be sure the USB can field upgrade with some standard ‘serial’ code. Or do we need a custom USB driver to do this?
UPDATE: Apparently this document is not supported?