machine.UART

The uart module is mainly used to drive the asynchronous serial port on the development board, and uart can be configured freely. There are 3 uarts in k210, and each uart can be freely mapped.

1. Construction#

1.1. Pin mapping#

Before using uart, we need to use fm to map and manage the chip pins. As shown below, set PIN10 as the sending pin of uart2 and PIN11 as the receiving pin of uart2

fm.register(board_info.PIN10,fm.fpioa.UART2_TX)
fm.register(board_info.PIN11,fm.fpioa.UART2_RX)

1.2. Constructor#

uart = machine.UART(uart,baudrate,bits,parity,stop,timeout, read_buf_len)

Create a new UART object with the specified parameters

1.2.1. Parameters#

• uart UART number, use the specified UART, which can be completed by pressing the tab key in machine.UART.
• baudrate: UART baud rate
• bits: UART data width, support 5/6/7/8 (the default serial port used by REPL (UARTHS) only supports 8-bit mode), default 8
• parity: Parity bit, support None, machine.UART.PARITY_ODD, machine.UART.PARITY_EVEN (the default serial port (UARTHS) used by REPL only supports None), the default is None
• stop: stop bit, support 1, 1.5, 2, default 1
• timeout: Serial port receiving timeout time
• read_buf_len: serial port receive buffer, serial port receives data through interrupt, if the buffer is full, it will automatically stop data receiving

1.2.2. return value#

• UART object

2. Method#

2.1. init#

It is used to initialize uart, which is generally initialized when constructing the object, here is used to reinitialize uart

uart.init(baudrate,bits,parity,stop,timeout, read_buf_len)

2.1.1. Parameters#

Same as constructor, but does not require the first UART number

2.1.2. return value#

no

2.2. read#

Used to read the data in the serial buffer

uart.read(num)

2.2.1. Parameters#

• num: The number of bytes read, generally fill in the buffer size, if the number of data in the buffer is not as large as num, then only the remaining data in the buffer will be returned

2.2.2. return value#

• bytes type of data

2.3. readline#

Used to read one line of serial buffer data

uart.readline(num)

• num: the number of rows read

2.3.1. return value#

*bytes type of data

2.4. write#

Used to send data using serial port

uart.write(buf)

2.4.1. Parameters#

• buf: Need to send to data

2.4.2. return value#

• The amount of data written

2.5. deinit#

Log off the UART hardware and release the occupied resources

uart.deinit()

2.5.1. Parameters#

no

2.5.2. return value#

no

2.6. repl_uart()#

Get the serial port object used for REPL

2.6.1. return value#

The serial port object used for REPL, the default initialization bit is 115200 8 N 1

3. Routine#

3.1. Routine 1#

Before running mileage, please make sure that PIN15 has been connected to PIN10, and PIN17 has been connected to PIN9

After running the program, you can see the printed information of baudrate:115200 bits:8 parity:0 stop:0 ---check Successfully in the terminal

from fpioa_manager import fm
from machine import UART
fm.register(board_info.PIN15,fm.fpioa.UART1_TX)
fm.register(board_info.PIN17,fm.fpioa.UART1_RX)
fm.register(board_info.PIN9,fm.fpioa.UART2_TX)
fm.register(board_info.PIN10,fm.fpioa.UART2_RX)
uart_A = UART(UART.UART1, 115200, 8, None, 1, timeout=1000, read_buf_len=4096)
uart_B = UART(UART.UART2, 115200, 8, None, 1, timeout=1000, read_buf_len=4096)
write_str ='hello world'
for i in range(20):
    uart_A.write(write_str)
    read_data = uart_B.read()
    read_str = read_data.decode('utf-8')
    print("string = ",read_str)
    if read_str == write_str:
        print("baudrate:115200 bits:8 parity:None stop:1 ---check Successfully")
uart_A.deinit()
uart_B.deinit()
del uart_A
del uart_B

3.2. Routine 2#

AT module serial port

fm.register(board_info.WIFI_RX,fm.fpioa.UART2_TX)
fm.register(board_info.WIFI_TX,fm.fpioa.UART2_RX)
uart = machine.UART(machine.UART.UART2,115200,timeout=1000, read_buf_len=4096)

3.3. Routine 3#

Modify the baud rate of the REPL serial port

from machine import UART
repl = UART.repl_uart()
repl.init(1500000, 8, None, 1, read_buf_len=2048)

3.4. Routine 3#

Modify the REPL serial port

from machine import UART

fm.register(board_info.PIN15,fm.fpioa.UART1_TX)
fm.register(board_info.PIN17,fm.fpioa.UART1_RX)
uart = machine.UART(UART.UART1, 115200)
UART.set_repl_uart(uart)

1. Construction
   1. Pin mapping
   2. Constructor
      1. Parameters
      2. return value
2. Method
   1. init
      1. Parameters
      2. return value
   2. read
      1. Parameters
      2. return value
   3. readline
      1. return value
   4. write
      1. Parameters
      2. return value
   5. deinit
      1. Parameters
      2. return value
   6. repl_uart()
      1. return value
3. Routine
   1. Routine 1
   2. Routine 2
   3. Routine 3
   4. Routine 3