Micropython-UART serial communication based on GPIO of Raspberry Pi

因为我的USB-TTL模块出了问题，所以只好使用GPIO口和树莓派实现通信，在此记录。

This article uses the GPIO port of the Raspberry Pi to realize the UART communication function. If readers want to use USB to TTL to realize UART communication, please refer to the article: Realize serial communication with upper and lower computers of Raspberry Pi through UART

GPIO pin function diagram (4B)

More specific:

Hardware connection

PYB	raspberry pie
TX(X3)	RX(15)
RX(X4)	TX(14)
GND	GND

UART communication code

PC Raspberry Pi

# -*- coding:utf-8 -*-
import serial
import time
ser = serial.Serial("/dev/ttyAMA0", 9600)
ser.flushInput()  
ser.write("begin".encode("utf-8")) 
def main():
    while True:
        count = ser.inWaiting() 
        if count != 0:
            recv = ser.read(count) 
            ser.write("Recv some data is : ".encode("utf-8"))  
            ser.write(recv)  
            ser.write("\n".encode("utf-8"))  
            print(ser.readline())
            ser.flushInput()

if __name__ == '__main__':
    main()

PYB end of lower computer

from pyb import UART

class Serial:
    def __init__(self, uart):
        self.uart = uart

    def data_check(self):
        return self.get_data()

    def send_data(self):
        data = "hi i'm pyboard!\n"
        data.encode("utf-8")
        self.uart.write(data)
        # print("send!")

    def get_data(self):
        start = utime.ticks_ms()
        data = self.uart.readline()
        if data != None:
            print("get data!!!!!")
            try:
                data.decode("utf-8")
            except:
                pass
            end = utime.ticks_ms()
            print("running time:", end - start)
            print(data)    
            return True
        else:
            return False
 
uart = UART(2, 9600)
ser = serial.Serial(uart)
while True:
	ser.send_data()
    ser.get_data()

Communication effect

Raspberry Pi

ALL 端

Obtained by program timing: each UART communication takes 19ms

Serial port transmission rate under different baud rates

Try to increase the UART baud rate of the Raspberry Pi and PYB to 115200. After restarting, I found that each serial communication takes only 2ms!

Reference article:

• The simplest Raspberry Pi + python3 + serial communication tutorial and solutions to problems