diff --git a/esp8266/uart.c b/esp8266/uart.c index f371935399..3207029fd2 100644 --- a/esp8266/uart.c +++ b/esp8266/uart.c @@ -222,6 +222,26 @@ int uart0_rx(void) { } */ +// Waits at most timeout microseconds for at least 1 char to become ready for reading. +// Returns true if something available, false if not. +bool uart_rx_wait(uint32_t timeout_us) { + uint32_t start = system_get_time(); + for (;;) { + if (input_buf.iget != input_buf.iput) { + return true; // have at least 1 char ready for reading + } + if (system_get_time() - start >= timeout_us) { + return false; // timeout + } + ets_event_poll(); + } +} + +// Returns char from the input buffer, else -1 if buffer is empty. +int uart_rx_char(void) { + return ringbuf_get(&input_buf); +} + int uart_rx_one_char(uint8 uart_no) { if (READ_PERI_REG(UART_STATUS(uart_no)) & (UART_RXFIFO_CNT << UART_RXFIFO_CNT_S)) { return READ_PERI_REG(UART_FIFO(uart_no)) & 0xff; diff --git a/esp8266/uart.h b/esp8266/uart.h index 2f762db5a2..8e09beea58 100644 --- a/esp8266/uart.h +++ b/esp8266/uart.h @@ -91,6 +91,8 @@ typedef struct { void uart_init(UartBautRate uart0_br, UartBautRate uart1_br); int uart0_rx(void); +bool uart_rx_wait(uint32_t timeout_us); +int uart_rx_char(void); void uart_tx_one_char(uint8 uart, uint8 TxChar); void uart_flush(uint8 uart); void uart_os_config(int uart);