Hello, If I use Serial.begin(,,SERIAL_TX_ONLY) to use GPIO3 as a LED output on ESP-01, I got no output on TX. But GPIO3 is usable with digitalWrite. In uart.c (line 174), the tx_pin is set to 255 if rx_enable is false. If I set it to 1, every thing is working fine. Thanks. ## <bountysource-plugin> Want to back this issue? **[Post a bounty on it!](https://www.bountysource.com/issues/34884260-serial-begin-serial_tx_only-doesn-t-works?utm_campaign=plugin&utm_content=tracker%2F14245935&utm_medium=issues&utm_source=github)** We accept bounties via [Bountysource](https://www.bountysource.com/?utm_campaign=plugin&utm_content=tracker%2F14245935&utm_medium=issues&utm_source=github). </bountysource-plugin>