Reading Serial Data Sent From Microbit in Windows

Question

I am trying to send data from my microbit to my windows PC over serial communication. I followed the example here from the microbit website but can't seem to get my Tera Term window to display anything.

The microbit is plugged into one of the USB ports on the front of my PC and has the following code on it:

basic.forever(function () {
    serial.writeLine("test")
})

When I add a new connection to Tera Term I select COM1 (this is the only option I have)

I then go into Setup > Serial Port and save the following settings

Unfortunately, this doesn't display any data, I have tried different USB ports and cables to no avail.

*"The microbit is plugged into one of the USB ports"* -- I have no idea what a *"microbit"* is, but I doubt that **COM1** will access it. **COM1** is typically reserved for a legacy PC serial port located at one of the traditional IBM PC UART port addresses. Your Windows installation seems to be missing the appropriate USB CDC/ACM device driver. Did you look for any unknown (USB) devices in the Device Manager? — sawdust, Jan 13 '20 at 06:08

score 0 · Accepted Answer · answered Jan 15 '20 at 04:30

The following python 3 code scans through the serial ports until it locates the one connected to your microbit, using the microbit's VID and PID. The script will then display port information. After this, the script displays anything sent through the serial port from the microbit.

You can use the port name to set up Tera Term, or let the script continue to display the data coming through the serial port. The default baud rate for the microbit is 115200. In the example output below, the port name is COM5. Each time you unplug and replug the microbit, the port name can change.

example output:

starting
looking for microbit
scanning ports
port: COM5 - mbed Serial Port (COM5)
pid: 516 vid: 3368
found target device pid: 516 vid: 3368 port: COM5
opening and monitoring microbit port

code:

import serial
import serial.tools.list_ports as list_ports


PID_MICROBIT = 516
VID_MICROBIT = 3368
TIMEOUT = 0.1


def find_comport(pid, vid, baud):
    ''' return a serial port '''
    ser_port = serial.Serial(timeout=TIMEOUT)
    ser_port.baudrate = baud
    ports = list(list_ports.comports())
    print('scanning ports')
    for p in ports:
        print('port: {}'.format(p))
        try:
            print('pid: {} vid: {}'.format(p.pid, p.vid))
        except AttributeError:
            continue
        if (p.pid == pid) and (p.vid == vid):
            print('found target device pid: {} vid: {} port: {}'.format(
                p.pid, p.vid, p.device))
            ser_port.port = str(p.device)
            return ser_port
    return None


def main():
    print('looking for microbit')
    ser_micro = find_comport(PID_MICROBIT, VID_MICROBIT, 115200)
    if not ser_micro:
        print('microbit not found')
        return
    print('opening and monitoring microbit port')
    ser_micro.open()
    while True:
        line = ser_micro.readline().decode('utf-8')
        if line:  # If it isn't a blank line
            print(line)
    ser_micro.close()


if __name__ == '__main__':
    print('starting')
    main()
    print('exiting')

Reading Serial Data Sent From Microbit in Windows

1 Answers1