How to use all 4 Lines of a SIMCOM A7672E-FASE (IEC-74)

[diplfranzhoepfinger]

Hello,

@david-cermak @igrr @others

the Example: https://github.com/espressif/esp-protocols/tree/master/components/esp_modem/examples/pppos_client

we use this Line: https://github.com/espressif/idf-extra-components/blob/86fab3ed9299d09173a5e98fd216aed14f14b6c7/usb/esp_modem_usb_dte/include/esp_modem_usb_config.h#L75

to access Interface 4 and 5 of the SIMCOM A6772-FASE.

it would be interesting to use also Interface 1 and 3 (guessed Numbers, but possible to find out):

• 1- Diagnostic port for log messages
• 4-AT port for AT commands communication
• 5-Modem port for PPP dial up
• 3-NMEA port for GNSS NMEA message output

1 is for the DIAG Server, if we have Problems to Report to SIMCOM we can take Modem Traces there,

3 is for the NMEA Port.

what to do to access the Other Ports as well ?

https://github.com/espressif/esp-idf/tree/master/examples/peripherals/usb/host/cdc/cdc_acm_vcp seems not to help, as it does tooo much Driver stuff and all this, we have already a lot inside the above Example.

Thanks,

Franz

[tore-espressif]

Hi @diplfranzhoepfinger thanks for issue.

Here's some information that might help you getting started:

• The rest of the ports (apart from 5-Modem port for PPP dial up) are not strictly related to 'modem' so I assume that they won't be implemented in esp_modem. cc @david-cermak
• The interface 5-Modem port for PPP dial up, is a different way to open a network connection. Since not all modems offer this interface and we already have implementation with AT commands, we do not plan to implement this
• The rest of the ports should act as regular COM ports. You can open them using usb_host_cdc_acm (which is also used for the AT interfaces - 4 and 5 in this case)
• You can open the interface with this function

  esp_err_t cdc_acm_host_open_vendor_specific(uint16_t vid, uint16_t pid, uint8_t interface_num, const cdc_acm_host_device_config_t *dev_config, cdc_acm_dev_hdl_t *cdc_hdl_ret);

  relevant example is here https://github.com/espressif/esp-idf/tree/master/examples/peripherals/usb/host/cdc/cdc_acm_host

• ICYMI, we also have neat component for parsing the NMEA messages https://components.espressif.com/components/igrr/libnmea

https://github.com/espressif/esp-idf/tree/master/examples/peripherals/usb/host/cdc/cdc_acm_vcp seems not to help, as it does tooo much Driver stuff and all this, we have already a lot inside the above Example.

This is not the first time that this example confused someone, I'll try to describe better what is this example for. Thanks for the feedback!

[diplfranzhoepfinger]

@tore-espressif 

Thanks, we will have a Look.

[tore-espressif]

@diplfranzhoepfinger Do you any any other inputs on this or can we close?

[rinstrum-franz]

@tore-espressif i did try, but it chrashes.

i need to deep into this again. Sorry for slow feedback so far.

i will reopen this issue once i go back into it.