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)

Here is a step-by-step rundown of what's shown in the animation:

  • 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.

Now, your script should be ready.  

  • Verify the changes you made against the example script shown below, then save it.
  • Disconnect the cyber:bot from the computer.
  • Connect the micro:bit to the computer that you plan to use to as the radio transmitter that will send messages to the cyber:bot.  
  • Click Save, and then click Send to micro:bit.

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()