Sorry for delay replay. Have you already found the solution?

Hello, Does anybody know what is the configuration for TTGO TCALL to run pppos_client example ? Currently I put : CONFIG_MODEM_TX_PIN=26 CONFIG_MODEM_RX_PIN=27 But I do not find the values for these ones and the example does not work : CONFIG_MODEM_RTS_PIN= CONFIG_MODEM_CTS_PIN= I took info from : ...

Hi! The TX pin shoud be 27 and RX pin 26. RTS and CTS doesn't matter. Don't forget that you should turn on the sim800 module before call sim800_init().