Transmitter Script for Keyboard Inputs

Let’s build on experience, and adapt a familiar script from a previous tutorial to use keyboard inputs.

Starting with the countdown_sender script from the Send and Receive Packets activity, you can replace its input statements with the ones from terminal_controlled_bot_tethered_try_this.  Then, the dictionary that’s created has to be adjusted to contain the vL, vR, and ms keys and values.  That’s the most crucial part of incorporating the terminal-in, radio-out part of your tethered app into script that wirelessly transmits.  

This animated GIF shows the script being modified.  

(View full-size: terminal_bot_controller_wireless.mp4)

You will also need to make a few other adjustments.  Here they are, step-by-step:

• Open terminal_controlled_bot_tethered_try_this
• Copy these lines:

    vL = int(input("Enter left speed: "))
    vR = int(input("Enter right speed: "))
    ms = int(input("Enter ms to run: "))

• Open the countdown_sender script from Send and Receive Packets.
• Paste the three lines you copied over these lines:

    text = input("Enter countdown start: ")
    value = int(text)
    message = input("Enter message after countdown: ")

• Find these two lines:

    dictionary['start'] = value
    dictionary['after'] = message

• Replace them with these three lines:

    dictionary['vL'] = vL
    dictionary['vR'] = vR
    dictionary['ms'] = ms

• Update the comment at the top of the script with the name terminal_bot_controller_wireless.
• Find these lines:

        print("Countdown App")
        print("micro:bit sender")

Replace them with this line:

        print("\nSpeeds are -100 to 100\n")

• Change the 50 in this line to 64:

        radio.config(channel=7,length=50)

It should look like this:

        radio.config(channel=7,length=64)

• If you are in a classroom and using assigned channels, update your channel.  

• Rename the script terminal_bot_controller_wireless.
• Save a copy of your work. 

Now, your script should be ready.  

• Verify the changes you made against the example script shown below, then save it.
• Load the code into the micro:bit you plan to use as the transmitter.

Example script: terminal_bot_controller_wireless.py

# terminal_bot_controller_wireless.py

from microbit import *
import radio

radio.on()
radio.config(channel=7,length=64)

sleep(1000)

print("\nSpeeds are -100 to 100\n")

while True:
    vL = int(input("Enter left speed: "))
    vR = int(input("Enter right speed: "))
    ms = int(input("Enter ms to run: "))

    dictionary = {  }
    dictionary['vL'] = vL
    dictionary['vR'] = vR
    dictionary['ms'] = ms

    packet = str(dictionary)
    
    print("Send: ", packet)
    radio.send(packet)
    
    print()