Serial output is garbled
I use the esp8266, serial output has been garbled, do not understand is that you provide the SDK problem, or need to have any additional settings.
Most likely your baud rate in SmarTTY settings doesn’t match the baud rate of the device. Most ESP8266 boards have the default baud rate of 74880 and most USB-to-UART adapters have a default rate of 115200. Please try setting the baud rate manually.