Trouble writing over serial

[EngineerNeil]

Hello all,

I am trying to get my BeagleBone Black to communicate with a Microcontroller (CC1310 Launchpad) over serial.
When I connect the Microcontroller to Windows, I can Use Putty and make a serial connection to (For example COM 13 and baud rate 9600) and I send "90000" it will send back something through the terminal window.
Now I am trying to do the same but with a Python program. Here is my attempt:

import datetime import serial import os def pwr_solenoid(solenoid0=0, solenoid1=0, solenoid2=0, solenoid3=0): # Defaults are for low signal values # compile output output = '9{solenoid0}{solenoid1}{solenoid2}{solenoid3}' \ .format(solenoid0=solenoid0, solenoid1=solenoid1, solenoid2=solenoid2, solenoid3=solenoid3).encode() with serial.Serial('/dev/ttyACM0', baudrate=9600) as ser: print("created connection to '/dev/tty/ACM0'\n") print("going to send:\t'{}'".format(output)) ser.write(output) ser.flush() ser.close() # I don't think you need this, but you would need to double check # for testing to console print(output.decode()) def read_from_uart(): # read from the serial connection try: with serial.Serial('/dev/ttyACM0') as ser: try: if not ser.in_waiting: raise Exception("No Data") val = ser.readline() data = "{dts}\t\t{val}\n".format(dts=datetime.datetime.utcnow(), val=val) # output to file filename = "{name}.txt".format(name=datetime.datetime.utcnow().strftime("%a%d%m%Y")) with open(filename, "+w") as file: file.write("{input}\n".format(input=data)) print("data received: {data}".format(data=data)) except (serial.SerialException, FileNotFoundError): print("Serialexception, mocking data *****") val = "85" data = "{dts}\t\t{val}\n".format(dts=datetime.datetime.utcnow(), val=val) print("data received: {data}".format(data=data)) except: print("Unexpected error") except (serial.SerialException, FileNotFoundError): print("Serialexception, mocking data *****") val = "85" data = "{dts}\t\t{val}\n".format(dts=datetime.datetime.utcnow(), val=val) print("data received: {data}".format(data=data)) def main(): os.system("clear") wait = True print("Enter solenoid values in form of 1/0 (1 == HIGH, 0 == LOW) or 'exit' to exit\n") print('\n') print("default value will remain '0000' until altered...\n") print("Note, after altered values are input, it will wait for input from UART||USB\n") print('\n') solenoid = '0000' while wait: solenoid = input("please input solenoid signal values.\n") if solenoid.lower() == "exit": break elif solenoid.lower() == "ports": import serial.tools.list_ports ports = [tuple(p) for p in list(serial.tools.list_ports.comports())] print(ports) elif solenoid.isdigit(): # checks to make sure all characters are digits (does not check for correctness of # individual characters pwr_solenoid(solenoid0=solenoid[0:1], solenoid1=solenoid[1:2], solenoid2=solenoid[2:3], solenoid3=solenoid[3:4]) read_from_uart() else: continue if __name__ == "__main__": main()

The program runs up to the point where it prints the output that is to be written over Serial , then says unexpected error, then prompts me to enter another input again. Any help would be appreciated there seems to be no syntax error in the code.

[j.crater]

Hello,

you get "Unexpected error" from exception handler in line #46.
Could you try to print any meaningful data/variables, before the exception happens?