I’m currently trying to do RS232 communication using python.
The communication manual is as shown in the picture below.
Stirrer control(rpm up to 1000)
I followed it and created the communication code, but it’s not working, so I’m contacting you guys.
The code below sends a signal to the OS20 pro model overhead stirrer to change the rpm value to 1000.
import serial
ser = serial.Serial('COM7', 9600, timeout=1)
def calculate_checksum(data): #calculate checksum
checksum = sum(data[1:]) & 0xFF
return bytes([checksum])
print("Start")
print(ser.name)
command = b'0xfe0xB10x030x00'
checksum = calculate_checksum(command)
command_with_checksum = command + checksum
ser.write(command_with_checksum)
print("Reading")
read = ser.readline().decode('ascii')
print("Reading: ", read)
ser.close()
Is there something wrong with the checksum side? Or is it because I made the command wrong and sent it?
Thank you for reading.
Sends a signal to the OS20 pro model overhead stirrer to change the rpm value to 1000.
Maybe
command = bytearray([0xfe, 0xB1, 0x03, 0x00])Or you can use
command = b'\xfe\xB1\x03\x00'. Python bytes literal has extra characters that aren’t hex, but alter the value of the string, Python byte literal, classmethod int.from_bytes(bytes, byteorder=’big’, *, signed=False)Thank you for your response. Sadly there is no response from the motor, it’s really hard to communicate.