ESP8266 UART
来自Jack's Lab
1 概述
- UART0
U0TXD --- PIN26 U0RXD --- PIN25 U0CTS --- PIN12 (MTCK) U0RTS --- PIN13 (MTDO)
- UART1 -- Only ouput pin, used for printing of debug information
U1TXD --- PIN14 (GPIO2)
Downloading: U0TXD+U0RXD or GPIO2+U0RXD
Communicating: UART0: U0TXD, U0RXD, MTDO(U0RTS), MTCK(U0CTS)
Debugging: UART1_TXD (GPIO2) can be used to print debugging information.
By default, UART0 will output some printed information when the device is powered on and is booting up. If this issue exerts influence on some
specific applications, users can exchange the inner pins of UART when initializing, that is to say, exchange U0TXD, U0RXD with U0RTS, U0CTS
2 SDK API
After calling void system_uart_swap():
U0TXD --- PIN13 (MTDO) ---> Output pin, NOT be pulled up externally in the initiallization stage U0RXD --- PIN12 (MTCK) U0CTS --- PIN25 U0RTS --- PIN26