0x0fe
commented
1 month ago i tried to force the result of the function to 8, a valid value, it passes this error but stil fails at the next step:
int PPPClass::networkMode() const {
if (_dce == NULL) {
return -1;
}
if (_mode == ESP_MODEM_MODE_DATA) {
log_e("Wrong modem mode. Should be ESP_MODEM_MODE_COMMAND");
return -1;
}
int m = 8;
// esp_err_t err = esp_modem_get_network_system_mode(_dce, m);
// if (err != ESP_OK) {
// log_e("esp_modem_get_network_system_mode failed with %d %s", err, esp_err_to_name(err));
// return -1;
// }
return m;
}Starting the modem. It might take a while!
[ 3389][V][PPP.cpp:281] begin(): Resetting the modem
[ 3389][V][esp32-hal-periman.c:235] perimanSetBusDeinit(): Deinit function for type GPIO (1) successfully set to 0x42007154
[ 3390][V][esp32-hal-periman.c:160] perimanSetPinBus(): Pin 7 successfully set to type GPIO (1) with bus 0x8
[ 3390][V][esp32-hal-periman.c:174] perimanSetPinBusExtraType(): Successfully set extra_type PPP_MODEM_RST for pin 7
[ 11492][V][PPP.cpp:306] begin(): Waiting for response from the modem
[ 14979][V][NetworkEvents.cpp:119] checkForEvent(): Network Event: 43 - PPP_START
[ 14980][V][PPP.cpp:99] _onPppArduinoEvent(): PPP Arduino Event 43: PPP_START
PPP Started
Manufacturer: +CGMI: "AirM2M"
Model: +CGMM: "Air724UG"
IMEI: xxxxxxxxxxxxxxxxxxx
Waiting to connect to network..2.0s
Attached: 1
State: 1
Operator: 2xxx5
IMSI: xxxxxxxxxxxxxxxxxxx
RSSI: 20
BER: 99
NetMode: 8
Switching to data mode...
Failed to connect to internet!
[ 81232][V][NetworkInterface.cpp:85] _onIpEvent(): ppp Lost IP
[ 81233][V][NetworkEvents.cpp:119] checkForEvent(): Network Event: 48 - PPP_LOST_IP
[ 81233][V][PPP.cpp:99] _onPppArduinoEvent(): PPP Arduino Event 48: PPP_LOST_IP
PPP Lost IP
david-cermak
Answers checklist.
General issue report
So, the target is ESP32C3, i tried to use PPPos with and AIR724UG, an LTE CAT1 modem based on RDA8910 , at first everything works, the network is attached and i get an IP, however as soon as we reach get_network_system_mode it fails, this command is non standard and seems specific to SIMCOM, when i looked up AT+CNSMOD i could see it is a SIMCOM command, it doesnt exist in AIR724 (and presumably others CAT1 modems).
https://github.com/espressif/esp-protocols/blob/5964eadbf5591e8c12ffa5c724c7ace083423239/components/esp_modem/src/esp_modem_command_library.cpp#L565C39-L565C49
I have tested with different modem settings, BG96, SIM7600, GENERIC and it always fails here. Now i wonder why this command was used, provided that it is not generic, and it could easily be replaced by a generic command, supported by all modems, doing the same thing. I understand not all modems can be supported, but it would be better if at least only generic commands were used, it would increase the chances of being compatible with most LTE modems, after all PPPos is a generic interface and it should work with any modern CAT1 / CAT4 modem, that is the purpose.
Also, there should be a simple way to pass a list of commands to use for connection of any modem, that is how it works on windows or linux, we can pass the list of commands required for a particular modem and it will always work. Here i did not found any way to make it work with other modems than SIM7xxx or BG96. The GENERIC mode still use the SIMCOM command CNSMOD for example, which is strange.
Now, i wonder how to fix this problem, there is an "user side" PPP library in the ESP32 core V3, but unfortunately it seems to only be a wrapper for the IDF library and i see no way to add, or better overwrite some functions to make it work with the AIR724UG or other modems. How should i proceed to make this possible? Here is the log, we can see the network is attached, i get an IP (presumably) but then it fails as soon as it tried to call CNSMOD, and finally the IP gets lost after a while, presumably because the network stack stopped responding acks or something.