lte_send_atcmd_sync says inappropriate I/O for device about nuttx

[acassis]

Hi @gcmurray1990 thanks for bring this issue to our attention.

About the warning you can fix using: %"PRIx32"

@SPRESENSE @masayuki2009 any idea why this error is happening?

[gcmurray1990]

@acassis Thank you for the quick reply. I understand that you all are busy, but is there anything I can do to help, or something I can clarify?

[acassis]

@gcmurray1990 I never used that LTE API, so I'm not much useful here, however looking the function lte_send_atcmd_sync() at apps/lte/lapi/src/lapi_other.c is seems like it doesn't apply directly to a serial line (this is way you saw -25 error: NOTTY). Look at lapi_req() it communicates with some socket, that is really strange.

I suspect this LTE is not a generic LTE libray, but something specific for Sony ALT1250. If that is the case I think we need to move apps/lte to apps/modem/alt1250.

@SPRESENSE since you are the author of that library, could you please help here?

[SPRESENSE]

Hi, @gcmurray1990
The LTE API is a method to request some to the user-sock daemon which is supporting LTE, like WAPI(Wireless API) of NuttX.
And the user-sock daemon is provided for each network devices which is supporting TCP/IP protocol layer.
Now, the LTE Usersock daemon in NuttX is only for Alt1250.
So, as @acassis said, currently the lapi is only for Sony Alt1250 device.

Please see document below to find a network stack structure in NuttX.
https://github.com/apache/nuttx/blob/master/Documentation/components/net/index.rst

[raiden00pl]

With some changes, LTE lib works also with nrf91 (you just need to get rid of alt1250 specific code).

[acassis]

@raiden00pl did you get it working?

[raiden00pl]

yes, but this lib is designed to work with socket interface, not a simple serial device. To make this work you have to implement usersock device with LTE_CMDID ioctls like here

nuttx/arch/arm/src/nrf91/nrf91_modem_sock.c

Line 479 in 07f0e0c

static int nrf91_ioctl_ltecmd(int fd, int cmd, unsigned long arg)

(in this case lte_send_atcmd_sync() that uses LTE_CMDID_SENDATCMD is not supported)

[acassis]

Nice! Thank you @raiden00pl !!! Maybe it could be a reference for @gcmurray1990 !!!

[acassis]

Maybe we need some board profile example to nRF91, when I git grep CONFIG_LTE_LAPI it only returns boards/arm/cxd56xx/spresense/configs/lte/defconfig

[gcmurray1990]

@raiden00pl , @acassis , and @SPRESENSE Thank you all for being so helpful and looking into this. I appreciate everyone's time very much.

[acassis]

You are welcome, if you face some issue integrating usrsocket to support SIM7600G-H please let us know