树莓派 - Arduino 通信

Question

I've designed a tachometer using an arduino setup and I get the output values(rpm), but since I don't have an wifi module, I've connected my arduino and raspberry pi 4 using usb. I can read the rpm value in the pi terminal. But now I need to send these data to an adafruit io page. How do I write the code to read the data from the usb port of my pi in real-time? I've written a script which can print it on the webpage but each time I've to write a value. It would be really helpful if i can get the answers. I'm new to coding and just exploring these.

from Adafruit_IO import*

ADAFRUIT_IO_USERNAME = '******'
ADAFRUIT_IO_KEY = '**********************' 

aio = Client(ADAFRUIT_IO_USERNAME,ADAFRUIT_IO_KEY)

try:
    test = aio.feeds('test')
except RequestError:
    test_feed = Feed(name='test')
    test_feed = aio.create_feed(test_feed)
val = 4   
aio.send('test',val) 

Answer 1

The below code is an example of what will work in Python, assuming your USB is connected at /dev/tty.usbmodem14201:

import serial
ser = serial.Serial('/dev/tty.usbmodem14201', baudrate=9600) # NB set your baudrate to the one you are using!
ser.flushInput()

while True: #constant loop to get readings in real time
    ser_bytes = ser.readline() #read the incoming message
    decoded_bytes = ser_bytes[0:len(ser_bytes)-2].decode("utf-8") #decode it
    print(decoded_bytes) # print out what you got or, alternatively, make a web call to Adrafruit