micro:Bit Robot Cart & micro:Bit Tilt Controller

[James46717]

After the success of the Move Mini Bulldozer using a second micro:Bit as a Tilt controller; I decided to apply it to a more powerful Cart.

micro:Bit control move:Mini

My continuing adventure with the BBC micro:Bit. After building the move:Mini and getting it working, I investigated how to control it. The video shows a Galaxy S5 phone with the Kitronik App. The grandson loved it, but the App kept disconnecting and he kept losing the screen by pressing where he should not. It was also a pain to set up the Bluetooth every time it disconnected. The Bluetooth and Neo Pixel libraries are incompatible. You can have one or the other, not both. I wondered if there …

The chassis is from the first Robot Cart I ever made. Arduino UNO & Motor Driver, Raspberry Pi Zero & Camera, Controlled via a web page. Pi Zero sent camera images to web page and commands from the webpage to the Arduino to drive the motors and servos. It worked very well but had a few limitations.

Outside taking pics of bike. Camera movable on servos.

An earlier version showing just Arduino UNO and Motor Shield.

In this Cart I learnt a lot about the micro:Bit. Most important was; some library functions are not time sensitive, they must have built in delays which are not ideal when other parts of the code need to execute immediately. ie checking for a command from the Radio function. The motor driver board can drive four motors, which is ideal in this case, and 8 servos. (link to board below)

Using the controller tilt function to drive the Cart is not ideal and lacks sensitivity. The Cart tends to drive too far or not enough. My 7 & 5 year old grandchildren loved it because of the much more powerful motors, it would drive over things and push stuff around. It would even pull a wheel stand in reverse. But it was hard to drive it where you wanted it accurately. I think I will abandon the idea of using the tilt function to move the Cart, probably buy a Kitronik Game controller board.

But other features of the micro:Bit will used. Maybe use the compass to align the Cart in the same direction as the controller. Add some sensors to detect objects in front of it, and a movement sensing and recording ability.

The 5 year old is very interested in big machinery. We discussed adding a bulldozer type attachment that could actually lift stuff. I am already developing a design in my head.

Anyway, the micro:Bit journey continues.

Regards
Jim

Motor Board

Kitronik Compact Robotics Board for BBC micro:bit

Future purchase, push button control better than tilt, more accurate.

Kitronik :GAME Controller for micro:bit

[James46717]

Controller Code - Javascript from Make Code App.
Thought I’d post this here, may be of use to someone.

input.onButtonPressed(Button.A, function () {
    if (Cmd == 7) {
        Cmd = 0
    } else {
        Cmd = 7
    }
})
function LED_Level () {
    Lvl = input.lightLevel()
    if (Lvl < 10) {
        Lvl = 10
    }
    led.setBrightness(Lvl)
}
function CheckMove () {
    if (control.millis() > LastCheck + 200) {
        Roll = input.rotation(Rotation.Roll)
        Pitch = input.rotation(Rotation.Pitch)
        LastCheck = control.millis()
        if (Roll < -30 && Math.abs(Pitch) < 30) {
            Cmd = 1
        } else if (Roll > 30 && Math.abs(Pitch) < 30) {
            Cmd = 2
        } else if (Math.abs(Roll) < 20 && Pitch < -20) {
            Cmd = 3
        } else if (Math.abs(Roll) < 20 && Pitch > 20) {
            Cmd = 4
        } else if (Roll < -20 && Pitch < -20) {
            Cmd = 5
        } else if (Roll > 20 && Pitch < -20) {
            Cmd = 6
        } else {
            Cmd = 0
        }
    }
}
input.onButtonPressed(Button.AB, function () {
    Cmd = 0
})
function LED_Burst (num: number) {
    for (let index = 0; index < 2; index++) {
        basic.showLeds(`
            . . . . .
            . . . . .
            . . # . .
            . . . . .
            . . . . .
            `)
        basic.pause(20)
        basic.showLeds(`
            . . . . .
            . # # # .
            . # # # .
            . # # # .
            . . . . .
            `)
        basic.pause(20)
        basic.showLeds(`
            # # # # #
            # # # # #
            # # # # #
            # # # # #
            # # # # #
            `)
        basic.pause(num)
        basic.clearScreen()
        basic.pause(100)
    }
    basic.showLeds(`
        . . . . .
        . . # . .
        . # # # .
        . . # . .
        . . . . .
        `)
}
input.onButtonPressed(Button.B, function () {
    if (Cmd == 8) {
        Cmd = 0
    } else {
        Cmd = 8
    }
})
function SendCmd () {
    if (Cmd != PrevCmd) {
        radio.sendNumber(Cmd)
        PrevCmd = Cmd
        basic.clearScreen()
        if (Cmd == 0) {
            led.plot(1, 2)
            led.plot(2, 1)
            led.plot(2, 2)
            led.plot(2, 3)
            led.plot(3, 2)
        } else if (Cmd == 1) {
            led.plot(0, 2)
            led.plot(1, 1)
            led.plot(1, 2)
            led.plot(1, 3)
            led.plot(2, 0)
            led.plot(2, 2)
            led.plot(2, 4)
            led.plot(3, 2)
            led.plot(4, 2)
        } else if (Cmd == 2) {
            led.plot(0, 2)
            led.plot(1, 2)
            led.plot(2, 0)
            led.plot(2, 2)
            led.plot(2, 4)
            led.plot(3, 1)
            led.plot(3, 2)
            led.plot(3, 3)
            led.plot(4, 2)
        } else if (Cmd == 3) {
            led.plot(0, 2)
            led.plot(1, 1)
            led.plot(2, 0)
            led.plot(2, 1)
            led.plot(2, 2)
            led.plot(2, 3)
            led.plot(2, 4)
            led.plot(3, 1)
            led.plot(4, 2)
        } else if (Cmd == 4) {
            led.plot(0, 2)
            led.plot(1, 3)
            led.plot(2, 0)
            led.plot(2, 1)
            led.plot(2, 2)
            led.plot(2, 3)
            led.plot(2, 4)
            led.plot(3, 3)
            led.plot(4, 2)
        } else if (Cmd == 5) {
            led.plot(0, 0)
            led.plot(0, 1)
            led.plot(0, 2)
            led.plot(1, 0)
            led.plot(1, 1)
            led.plot(2, 0)
            led.plot(2, 2)
            led.plot(2, 3)
            led.plot(2, 4)
        } else if (Cmd == 6) {
            led.plot(2, 0)
            led.plot(2, 2)
            led.plot(2, 3)
            led.plot(2, 4)
            led.plot(3, 0)
            led.plot(3, 1)
            led.plot(4, 0)
            led.plot(4, 1)
            led.plot(4, 2)
        }
    }
}
let Pitch = 0
let Roll = 0
let Lvl = 0
let LastCheck = 0
let PrevCmd = 0
let Cmd = 0
LED_Level()
LED_Burst(1)
Cmd = 0
PrevCmd = 0
let Count = 0
LastCheck = 0
radio.setGroup(1)
basic.forever(function () {
    if (Cmd != 7 && Cmd != 8) {
        CheckMove()
    }
    SendCmd()
})

[James46717]

Cart Code - Javascript from Make Code App.

function Left (deg: number) {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Forward, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Forward, 70)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Reverse, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Reverse, 70)
    Delay = Math.map(deg, 0, 90, 0, 600)
    basic.pause(Delay)
    All_Off()
}
radio.onReceivedNumber(function (receivedNumber) {
    Command = receivedNumber
})
function Veer_Right () {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Forward, 50)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Forward, 50)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Forward, 20)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Forward, 20)
}
function Turn_Right () {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Reverse, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Reverse, 70)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Forward, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Forward, 70)
}
function All_Off () {
    Kitronik_Robotics_Board.motorOff(Kitronik_Robotics_Board.Motors.Motor1)
    Kitronik_Robotics_Board.motorOff(Kitronik_Robotics_Board.Motors.Motor2)
    Kitronik_Robotics_Board.motorOff(Kitronik_Robotics_Board.Motors.Motor3)
    Kitronik_Robotics_Board.motorOff(Kitronik_Robotics_Board.Motors.Motor4)
}
input.onButtonPressed(Button.A, function () {
    Turn_Left()
    basic.pause(1000)
    All_Off()
})
function LED_Level () {
    Lvl = input.lightLevel()
    if (Lvl < 10) {
        Lvl = 10
    }
    led.setBrightness(Lvl)
}
function LED_Burst (num: number) {
    for (let index = 0; index < 2; index++) {
        basic.showLeds(`
            . . . . .
            . . . . .
            . . # . .
            . . . . .
            . . . . .
            `)
        basic.pause(20)
        basic.showLeds(`
            . . . . .
            . # # # .
            . # # # .
            . # # # .
            . . . . .
            `)
        basic.pause(20)
        basic.showLeds(`
            # # # # #
            # # # # #
            # # # # #
            # # # # #
            # # # # #
            `)
        basic.pause(num)
        basic.clearScreen()
        basic.pause(100)
    }
}
function All_BCK (spd: number) {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Reverse, spd)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Reverse, spd)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Reverse, spd)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Reverse, spd)
}
function Veer_Left () {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Forward, 70)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Forward, 70)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Forward, 20)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Forward, 20)
}
function Turn_Left () {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Forward, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Forward, 70)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Reverse, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Reverse, 70)
}
function All_FWD (spd: number) {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Forward, spd)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Forward, spd)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Forward, spd)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Forward, spd)
}
function Right (deg: number) {
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor1, Kitronik_Robotics_Board.MotorDirection.Reverse, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor2, Kitronik_Robotics_Board.MotorDirection.Reverse, 70)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor3, Kitronik_Robotics_Board.MotorDirection.Forward, 80)
    Kitronik_Robotics_Board.motorOn(Kitronik_Robotics_Board.Motors.Motor4, Kitronik_Robotics_Board.MotorDirection.Forward, 70)
    Delay = Math.map(deg, 0, 90, 0, 600)
    basic.pause(Delay)
    All_Off()
}
let Lvl = 0
let Delay = 0
let Command = 0
LED_Level()
LED_Burst(1)
radio.setGroup(1)
let Speed = 90
Command = 0
basic.showIcon(IconNames.Yes)
basic.forever(function () {
    if (Command == 0) {
        All_Off()
    }
    if (Command == 1) {
        Left(30)
    }
    if (Command == 2) {
        Right(30)
    }
    if (Command == 3) {
        All_FWD(60)
    }
    if (Command == 4) {
        All_BCK(60)
    }
    if (Command == 5) {
        Veer_Left()
    }
    if (Command == 6) {
        Veer_Right()
    }
    if (Command == 7) {
        Turn_Left()
    }
    if (Command == 8) {
        Turn_Right()
    }
})

[James]

Hi James,

Awesome work here! Lovely to see the quick progress you and your son are making

Keep 'em coming!
-James