That resistor is there because of EMC reasons... if during your EMC testing you find out that there's emissions from your UART1 TX pin, you could try also putting a 470 ohm resistor there, but from what I know, it's only an issue on UART0. Regardless, having or not having the resistor shouldn't aff...

The issue is still being investigated. But just out of curiosity, I am using UART1, there is no resistor 470 Ohm between the esp TXD and modem RXD.. is it mandatory?

I've created git issue:

https://github.com/espressif/esp-idf/issues/7803

I appreciate any valuable feedback on the issue

Ohh ok,might @ESP_cermak will help us here.. I notice also one more thing, its always crashing when exiting from PPP [0;32mI (511128) esp-modem: entering esp_modem_stop_ppp...[0m [0;31mE (512058) esp-modem: esp_dte_handle_line(124): handle line failed[0m [0;33mW (512058) pppos_example: Unknow line r...

Can you decode that backtrace? Hi, Thanks. Sure please find below: Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled. Core 1 register dump: PC : 0x400d52e5 PS : 0x00050031 A0 : 0x400826f8 A1 : 0x3ffb0dc0 0x400d52e5: uart_ll_get_intsts_mask at C:/esp4/esp-idf/component...

Can I get any feedback here????

I've tried ESP_cermak example, I've let it running for hours but after awhile, I'am getting the famous "GGuru Mediation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled." One more thing here, I notice that its showing Core 1 while I dont have any task running on it..? [0;32mI (334856...

Hi, I have the same issue. While I've managed to make the re-connection work, I've let it to cycle through disconnection and re-connection for hours just to make sure that there is no sudden crashes.. But I'm getting random crash: [0;33mW (2115847) event: handler already registered, overwriting[0m [...

Hi,
Thanks for the reply. God bless, we've found the issue it was from the crystal and its capacitors. we've replaced it along with its caps and its working now. Thanks.

Hi Sorry for pumping this thread. But unfortunately we are facing the same behavior, everything works correctly, even UART/Serial but when canning wifi shows zero APs. We are using 40mhz crystal. We've reflowed the PCBs also. Moreover this is not the case for all our production, only few of them, sh...