Connecting bluetooth keyboard automatically at boot

Question

I made a raspberry pi robot that you can control with the keyboard and I want to use my bluetooth keyboard with it. The python program automaticley starts. I used /etc/rc.local to do this.

#!/bin/sh -e
sudo python3 /home/pi/startup/keyboardControl.py &
exit 0

And this is the content of the keyboardControl.py file

from keyboard import is_pressed
import motorControl
motorLeft = motorControl.DCmotor(33, 35, 37)
motorRight = motorControl.DCmotor(36, 40, 38)
speeds = [0, 25, 50, 75]
speed = 0
try:
    while 1:
        if is_pressed('up'):
            if is_pressed('right'):
                motorLeft.setSpeed(int(speeds[speed]*1.25))
                motorRight.setSpeed(int( speeds[speed]*0.75 ))
            elif is_pressed('left'):
                motorLeft.setSpeed(int( speeds[speed]*0.75 ))
                motorRight.setSpeed(int( speeds[speed]*1.25 ))
            else:
                motorLeft.setSpeed(speeds[speed])
                motorRight.setSpeed(speeds[speed])
        elif is_pressed('down'):
            if is_pressed('right'):
                motorLeft.setSpeed(int( speeds[speed]*-1.25 ))
                motorRight.setSpeed(int( speeds[speed]*-0.75 ))
            elif is_pressed('left'):
                motorLeft.setSpeed(int( speeds[speed]*-0.75 ))
                motorRight.setSpeed(int( speeds[speed]*-1.25))
            else:
                motorLeft.setSpeed(speeds[speed]*-1)
                motorRight.setSpeed(speeds[speed]*-1)
        elif is_pressed('left'):
            motorLeft.setSpeed(int( speeds[speed]*-1.25))
            motorRight.setSpeed(int( speeds[speed]*1.25))
        elif is_pressed('right'):
            motorLeft.setSpeed(int( speeds[speed]*1.25))
            motorRight.setSpeed(int( speeds[speed]*-1.25))
        else:
            motorLeft.setSpeed(0)
            motorRight.setSpeed(0)

        if is_pressed('1'):
            speed = 0
        elif is_pressed('2'):
                speed = 1
        elif is_pressed('3'):
            speed = 2
        elif is_pressed('4'):
            speed = 3

        if is_pressed('q'):
            raise
except:
    motorControl.stopAll()

As you see I used the keyboard library and I also use a library I make myself to control the motors. This works if you use a keyboard via the usb, but if I use a bluetooth keyboard it won't work. I think this is because the code runs before the keyboard is automatically connected. Is there any way to force the bluetooth connection before the program runs?

Answer 1

I would get your program to wait till the keyboard is connected.

Tools that you could use to check this are:

hcitool scan

or if you are sure of the keyboard MAC address:

sudo l2ping -c 1 xx:xx:xx:xx:xx:xx

I personally would use the first and check it’s output against a list of known keyboards as you may have more than one keyboard you are connecting rather than lots of different pings.