Introduction:
This motor driver board for the BBC micro:bit allows two motors to
be driven simultaneously with forward, reverse & stop control, making it ideal for
designs such as buggies. It is based on the DRV8833 motor driver IC, which has
built in short circuit, over current and thermal protection.
The board includes an integrated Edge Connector slot for your BBC micro:bit to
easily slot into. It also features external connections to the button A and button
B inputs. This allows additional switches / inputs to be connected to the motor
driver board and the state of these can then be read by the BBC micro:bit.
There are 2 additional inputs / outputs. These can be used for connecting a range
of parts and can be used in either digital or analog modes.
The board also produces a
regulated 3V supply
that is fed into the 80 way
connector
to power the inserted BBC micro:bit,
removing the need to power the
BBC micro:bit directly.
Inserting a BBC micro:bit:
To use
the motor driver board the BBC
micro:bit should be inserted firmly
into the connector as shown left.
The board has been designed so
that the BBC micro:bit can be
inserted either way around (facing
forward or backwards) however if
you wish to use the broken out
pins the LED matrix on the BBC
micro:bit must be facing them.
Layout:
Terminal Block for power (4.5-6V).
BBC micro:bit
compatible connector.
BBC
micro:bit
Pins
broken
out with
0.1”
spacing.
Terminal blocks for
connecting Motor 1 and
Motor 2.
Examples of board in use:
This
breakout board is used in our ‘BBC
micro:bit buggy’ example. For
more details visit
Terminal blocks
to P1 and P2.
These can be used
as inputs or
outputs in either
digital / analog
modes. Additional
3V connections
are also provided.
Terminal block connections to Button
A and B on the micro:bit (taken low
when a pressed) with additional GND
(0V) connections.
Electrical Information
Operating Voltage (Vcc)
Number of motor channels
Typical motor output Voltage (Vm) @ 1.5A output per channel
Max Current per motor channel
Digital only inputs
Digital or analog input / output pins (P1 & P2)
Digital output drive current
4.5V to 6V
2 (2 motors with forward + reverse control, controlled by P0,
P8, P12 & P16)
Vm = Vcc – 0.3V
1.5A
2 (button A / B)
2 (P1 & P2)
5mA
Motor Control Pins
(forward and reverse directions can vary depending on how the motors are connected)
P8
0
1
0
1
P12
0
0
1
1
Motor 1 Function
Coast
Forward
Reverse
Brake
P0
0
1
0
1
P16
0
0
1
1
Motor 2 Function
Coast
Forward
Reverse
Brake
Motor Driver Board for the BBC micro:bit
www.kitronik.co.uk/5620
Example Connections and Touch Develop Code
When the Touch Develop script shown below is transferred on to a BBC micro:bit, which is then inserted into the Motor Driver
Board, with the motors and switches connected as shown below right, the functionality described in the boxed areas should be
observed.
If P12 is on and P8 is off then
Motor 1 will spin one way. If
P12 is off and P8 is on Motor 1
will spin the opposite way.
If P16 is on and P0 is off then
Motor 2 will spin one way. If
P16 is off and P0 is on Motor 2
will spin the opposite way.
Pressing this button connects
P1 to 3V bringing it high (1) and
activating the blue section of
code to the left.
Pushing this button connects
P2 to 3V brings it high (1) and
activates the yellow segment
of code.
Pushing this button brings the
BTN_B pin low (0) and
releasing it activates the
‘button is pressed (B)’ function
in the code.
This button works the
same way as BTN_B,
but it will activate the
‘button is pressed (A)’
function in the code.
Dimensions
67.4mm
25mm
62mm
4mm
16mm
4mm
1.6mm
42mm
(Dimensions +/- 0.8mm)
