Introduction

It's a simple "** Introduction to learning and implementing serial communication **".

What is serial communication?

Serial communication: A communication method that sequentially transmits digital data bit by bit. Parallel communication: Communication method for simultaneous transmission of multiple bits of digital data

Communication method	Advantages	Disadvantages
Serial communication	low cost	slow
Parallel communication	High cost	fast

If you want to know more, this article is recommended. I tried to summarize the serial communication method for beginners of electronic work in an easy-to-understand manner

Implemented in Python (pyserial)

Install pyserial

First, hit the following command to install the package. (You don't have to enter $.)

`python`


$ pip install pyserial

Search for devices that can communicate

First, search for devices that can communicate. Try hitting the following command. (The second line is the response from the terminal.)

`python`


$ ls -l /dev/tty.*
crw-rw-rw-  1 root  wheel   18,   0 11 28 17:48 /dev/tty.Bluetooth-Incoming-Port

A device called /dev/tty.Bluetooth-Incoming-Port was found.

Read

Next, let's read it.

`read.py`


import serial

readSer = serial.Serial('/dev/tty.Bluetooth-Incoming-Port',9600, timeout=3)
c = readSer.read() # 1 byte
string = readSer.read(10) # 10 byte
line = readSer.readline() # 1 line (upto '\n')
print("Read Serial:")
print(c)
print(string)
print(line)
readSer.close()

Code description

Install the package.
Set the device name, baud rate (communication speed), timeout, and open the port.
(serial.Serial (device name, baud rate, timeout))
Read and print.
Close the port.

Write

`write.py`


import serial

serialCommand = "test"
writeSer = serial.Serial('/dev/tty.Bluetooth-Incoming-Port',9600, timeout=3)
writeSer.write(serialCommand.encode())
writeSer.close()

Code description

Install the package.
Set the device name, baud rate (communication speed), timeout, and open the port.
(serial.Serial (device name, baud rate, timeout))
Encode and write the command you want to send.
Close the port.

Whole sample code

`main.py`


import serial

print("===== Start Program =====\n")

# Set Parameter
deviceName = '/dev/tty.Bluetooth-Incoming-Port'    # search by `ls -l /dev/tty.*`
baudrateNum = 9600
timeoutNum = 3
print("===== Set Parameter Complete =====\n")

# # Read Serial
readSer = serial.Serial(deviceName, baudrateNum, timeout=timeoutNum)
c = readSer.read()
string = readSer.read(10)
line = readSer.readline()
print("Read Serial:")
print(c)
print(string)
print(line)
readSer.close()
print("===== Read Serial Complete =====\n")

# Write Serial
serialCommand = "test"
writeSer = serial.Serial(deviceName, baudrateNum, timeout=timeoutNum)
writeSer.write(serialCommand.encode())
writeSer.close()
print("===== Write Serial Complete =====\n")

print("===== End Program =====\n")