Make it with Micromite
Phil Boyce – hands on with the mighty PIC-powered, BASIC microcontroller
Part 17: Building the Micromite Robot Buggy
The power circuit is greatly simplified
thanks to the LiPo Charger/Booster
module (MOD3). When a 3.7V LiPo
battery is plugged into this booster
module, there will be an output of
approximately 5.2V on the 5V pin
(assuming the battery has some charge
in it!). Pulling MOD3’s EN pin low (0V)
turns off the MOD3 5V ouput. The EN
M 2
JS
JP
The code in this article is available
for download from the PE website.
48
+
2
JS
+ V
M O D 2
U S B B oB
–
M 1
JP
1
2
JP
7
JP
E E P
5V
9
JP
JS
3
10
23
24
21
22
0V
17
18
15
16
U S B
+
–
L iP o
4
1
5V
9
Connectors
JS
26
E N
M O D 3
L iP o ch arger/
booster
M I WM
5
0 V
+ 5 V
4
5
0V
22
IN 4
IN 3
0 V
+ V
IN 1
5V
JP
4
8
R 1
0kΩ
0V
0 V
OU T 1
OU T 2
OU T 3
5V
M O D 1
M otor drive r
JP
N ote: S 1 is a
push- to- break
button
1
3
U L T
JP
25
Micromite code
P ower
circuit
S 1
Motor circuit
The motor circuit comprises a motor
driver module (MOD1), and the two
DC motors (M1, M2). The motor driver
module simply boosts/‘amplifies’ four
signals (two for each motor) from the
Micromite. Each Micromite output pin
can only supply a maximum current
of circa 20mA and hence the motor
module ‘amplifies’ this to what the motors
require; the exact figure depends on the
motor type (and gear ratio) used, and also
the weight of the robot. Two MKC pins
control one motor, and two more MKC
pins control the other motor. A PWM
signal is used on one side of each motor
to control its speed, and this is why pins
The Micromite
Robot Buggy (MRB)
0 V
M otor circuit
OU T 4
Fig.18 shows the MRB’s circuit diagram,
and as with most MIWM modules in
this series, the circuit is relatively
straightforward. It is just a matter of
connecting three modules (MOD1MOD3), and two components (S1, R1),
to the correct Micromite pins. There are
three distinct parts to the schematic: the
motor circuit, the power circuit, and the
connectors for attaching existing MIWM
hardware modules. Let’s take each of
these in turn.
Power circuit
IN 2
Circuit diagram
4 and 5 have been used (PWM 1A and
1B). Standard I/O pins can be used to
drive the other contact on each motor –
here we have used pins 9 and 10.
–
introduced you to the new Micromite
Robot Buggy (MRB). This month, we
will work through the assembly process
resulting in the MRB shown to the right.
Please note that references this month
to Fig.17 and below mean photos and
diagrams from last month, hence you
will need to have a copy of Part 16 (PE,
May 2020) to hand.
+
I
n last month’s article, we
3
2
5
4
7
6
9
0V
11
10
JP
6
JS
5
3.3V
12
14
Fig.18. Circuit diagram for the MRB. There are three distinct parts: motor circuit,
power circuit and connectors for MIWM hardware.
Practical Electronics | June | 2020
pin is tied to +V via an internal 200kΩ
pull-up resistor. You can see in Fig.18
that the EN pin is also connected to 0V
via R1 (10kΩ), jumper-link (JP8), and
a push-to-break button (S1). With the
jumper link in place (ignore pin 22 for
now), the 5.0V output is off because
the potential divider formed by 10kΩ
and 200kΩ means EN is still effectively
pulled low to nearly 0V. If the jumper
link is removed, the EN pin is pulled
high by the module’s internal 200kΩ
resistor, and the 5V output will turn
on. Refitting the jumper link will turn
off the 5V output once again (for the
aforementioned reasons).
Now consider button (S1). When
pressed, the 5V output will be on, and
when released, the output will be off.
Next we turn to the pin 22 connection.
When S1 is pressed, the 5V output turns
on (and the MKC powers up). If our
program sets pin 22 high at the start of
the code, then when S1 is released, the
5V output will not switch off because
the EN pin is being held high via pin 22.
So how do we now turn off the power
other than disconnecting the battery? The
answer is to simply set pin 22 low. This
is just a nice little trick to allow the robot
to be turned off with a touch-screen or
infrared remote control. Turning the robot
on will always require S1 to be pressed
(or the jumper link to be removed).
When it comes to charging the LiPo
battery, the USB pin on the LiPo Charger/
Booster module needs to be fed with a
5V power source (with a capacity of at
least 1A).
MOD2, the USB breakout board
(BoB) is used as a socket to supply 5V
charging power to MOD3 USB pin.
MOD2 is mounted at the back of the
robot, providing a convenient place to
attach a 5V supply to recharge the robot’s
battery. We recommend using a phone
charger for this function, or alternatively
a RaspberryPi PSU (these have a microUSB connector and can comfortably
supply at least 2A).
MIWM Connectors
The connectors need to be positioned
correctly (as shown in Fig.21) to allow
connection to other MIWM hardware
modules. They pass the MKC signals to
the daughterboard, and also to any other
MIWM module that is plugged in. They
do not affect the circuit in any other way.
Pin mappings
Before we go into specific assembly
details, it is first worth having a quick
look at how the 19 available Micromite
I/O pins are being used in the MRB – see
Table 2. You can see that most pins have
been assigned already; however, there
are still four available for future use.
Practical Electronics | June | 2020
Motor positive (+) terminals
H1a
H3
H1b
H2a
H4
SL1
SL2
H2b
H6*
H5*
SL3*
H7*
SL4*
H8*
SL5
SL6
H10*
H9*
SL8
H11
H12
SL7
H13a-d
Holes and slots marked with ‘*’ only used
in protoype – ignore for your buggy
H14a-d
Fig.19. The underside of the buggy showing slot (SLx) and hole (Hx) references. As
shown, the MKC and Bluetooth module have yet to be attached.
Guide to assembling the
MRB chassis
We will now work through two guides
for assembling the robot chassis module.
Once complete, we will run through some
basic testing, and then plug everything
together in order to run a simple demo
program. Rather than go into extensive
assembly details, we will simply provide
numbered step-by-step instructions.
When used in conjunction with the
photos, they should easily provide you
with enough information. If at any time
you get stuck, or have any questions,
then please do get in touch by email. So
let’s get started…
Table 2: Micromite pin assignments for the Micromite Robot Buggy.
Pin No.
Pin function
To module
Robot function
2
I/O
TFT
TFT D/C pin
3
SPI OUT
TFT
TFT SPI IN
4
PWM 1A
MOTOR
Motor 1
5
PWM 1B
MOTOR
Motor 2
6
I/O
TFT
TFT CS pin
7
I/O
TFT
TFT Touch_CS pin
9
I/O
MOTOR
Motor 1
10
I/O
MOTOR
Motor 2
14
SPI IN
TFT
TFT SPI OUT
15
I/O
TFT
TFT Touch_IRQ pin
16
Infrared
TSOP
IR receiver
17
2
I C CLK and I/O
–
Available for future use
18
2
I C DATA and I/O
–
Available for future use
21
I/O
–
Available for future use
22
I/O
LIPO
EN pin
23
I/O
TFT
TFT RESET pin
24
PWM 2B
–
Available for future use
25
SPI CLK
TFT
TFT SPI CLOCK
26
PWM 2A
TFT
PIEZO Sounder
49
Assembling the chassis
1. Identify the correct orientation of the
acrylic chassis. Fig.2 shows the top
surface onto which the daughterboard
will be mounted. Fig.19 shows the
underside, to which the motors and
wheel mounts will be fixed (and
this is the side we require now). The
orientation is determined by slot
SL7,which needs to be on the left, as
shown in Fig.19.
2. Push-fit the two wheel mounts firmly
into the two sets of four holes, H13 and
H14 on the underside of the chassis.
Ensure that the threaded hole is nearer
the outer edge (Fig.19)
3. Place one of the motors into a motor
mount so that one side of the gearbox
is covered (Fig.16a). Ensure that the
gearbox sits into the groves that are inside
the motor mount. Before fixing it to the
underside of the chassis, we first need
to ensure that the motor is inserted with
the contacts in the correct orientation.
Referring to Fig.15 you can see that one
of the motor contacts is marked with a
‘+’ symbol. This needs to be on the left
side of the motor mount, when fixed
to the chassis. If it isn’t, simply flip the
motor over in the motor mount. Once
correct, fix the motor mount on the
underside of the chassis into hole pair
H1 using the supplied nuts and bolts
(see Fig.16b and 16c). Repeat for the
other motor into hole pair H2.
4. Identify the two driving wheels; these
have a smaller D-shaped hole in the
centre of the wheel (as opposed to a
larger round hole) – see Fig.4. Each
driving wheel slides onto the D-shaped
motor shaft that can be seen in Fig.16b.
Align the wheel with the motor shaft
and carefully slide one wheel onto
each D-shaped motor shaft so that the
end of the motor shaft sits flush with
the wheel hub. Be careful not to push
the wheel on at an angle as this will
twist the motor shaft and potentially
damage the motor. Note that a fair bit
of force may initially be required to
get the wheel onto the shaft. Take your
time with this step – it is the trickiest
part of assembly!
5. The two auxiliary wheels are attached
to the two wheel mounts by using the
shorter screws (spindles) supplied in
the kit (you can discard the longer
spindles). Refer to Fig.17 to see the
location of the nuts and washers. Screw
into the wheel mount and then add
the supplied nut to lock it into place
(see Fig.19). Check the two axillary
wheels spin freely.
Fig.20. Stripboard layout showing position
of track-cuts, wire-links, components,
and modules.
50
B
3
4
5
6
7
8
9
1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5 3 6
A
B
D
D
E
E
F
F
G
H
K
M
2
C
C
G
1
A
J
H
I
I
J
K
L
L
JP1, JP2, JP5 and
JP6 marked in blue N
are downward facing O
pins (inserted from P
above).
Q
R
S
T
U
V
W
X
Y
Z
A A
B B
C C
D D
E E
F F
G G
H H
II
J
K K
L L
M M
N N
OO
P P
Two track cuts Q Q
carefully made R R
with scalpel or S S
Stanley knife
T T
U U
V V
W W
X X
X X
W W
V V
U U
T T
S S
R R
Q Q
P P
OO
N N
M M
L L
K K
J
II
H H
G G
F F
E E
D D
C C
B B
A A
Z
Y
X
W
V
U
T
S
R
Q
P
O
N
M
L
K
J
I
H
G
F
E
D
C
B
A
JP1
M
JP2
N
O
P
Q
R
JP3
S
T
U
MOD1
V
W
X
JP9
JP4
Y
Z
A A
MOD3
B B
C C
D D
E E
F F
G G
H H
II
JP5
JS3
R1
J
K K
L L
JS4
M M
N N
OO
P P
Q Q
R R
S S
T T
U U
V V
W W
X X
JP8
JP6
JS5
MOD2
S1
1
2
3
4
5
6
7
8
9
1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5 3 6
X X
W W
V V
U U
T T
S S
R R
Q Q
P P
OO
N N
M M
L L
K K
J
II
H H
G G
F F
E E
D D
C C
B B
A A
Z
Y
X
W
V
U
T
S
R
Q
P
O
N
M
L
K
J
I
H
G
F
E
D
C
B
A
1
2
3
4
5
6
7
8
9
1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7 2 8 2 9 3 0 3 1 3 2 3 3 3 4 3 5 3 6
Practical Electronics | June | 2020
MOD1 yellow/orange cap
BT module
MKC
MOD2 mounted
flush with stripboard
Fig.21. Robot Buggy with the daughterboard attached to the
chassis. The MKC and Bluetooth modules are attached on the
underside. TFT module yet to be attached.
6. Place the two tracks over each pair
of wheels. Ensure the track teeth sit
properly around the toothed wheels
(Fig.4). Then, manually turn each track
slightly to check that the wheels turn
– you will probably hear the gearbox
mechanism turning as you do this.
7. Take the four 12mm, M3 nylon screws
and from the underside of the chassis,
insert them into holes H3, H4, H11
and H12. Use four of the nylon nuts
to hold the screws in place. These four
upward-facing screws will be used
later as mounting posts to position
the daughterboard onto the chassis
(and the four remaining nylon nuts
will secure it down).
That completes the chassis assembly. Do
check that everything seems correct and
ensure that you address any issues before
moving on. We will now work through
the assembly of the daughterboard.
Assembling the daughterboard
Throughout the following steps, refer to
Fig.20 for the layout of the stripboard.
1. Mark the position of all the track cuts.
Check them all at least twice before
making the cuts! Be sure to remove
any shards of track to avoid shorts
with neighbouring tracks.
2. Mark the four positions (M8, M28,
TT8, TT29) of the mounting holes
shown in Fig.20. Use a 3mm drill
bit to make the holes.
3. Mark the locations of the 20 wire
links. Tip: use a felt-tip pen and mark
the ‘start’ and ‘end’ holes on the topside of the stripboard. Check these at
least twice, making any corrections.
Then simply work through one link
at a time by wiring up the ‘felt-tip
dots’. Check that there are no solder
shorts to neighbouring tracks.
Practical Electronics | June | 2020
Fig.22. The underside of the Robot Buggy with the MKC and
Bluetooth module attached.
4. Prepare all pin-strips (JPxx) and
sockets (JSxx) as shown in Fig.14
(carefully observing where pins and
contacts need to be removed from the
plastic body)
5. The motor driver module (MOD1)
has a solder-link on the underside –
ensure that this is shorted out with
a blob of solder.
6. Solder the two 6-way pin-strips
(JP3 and JP4) onto the underside
of motor module MOD1, and then
solder the module into position on
the daughterboard. Ensure that the
yellow/orange capacitor on the motor
driver module is towards the upperleft corner – refer to Fig.21.
7. Solder the modified 8-way pin strip
(JP9) into position on the stripboard.
Ensure that only 5-pins are in the
modified 8-way pin-strip (as shown
in Fig.14), and also that it is mounted
the correct way round (refer to Fig.20).
Do not solder the LiPo module yet!
8. Position the USB BoB (MOD2)
directly onto the stripboard. Use
the 5-way pin-strip (JP7) and insert
the long pins down through the USB
BoB continuing down through the
stripboard into holes SS32-SS36.
Solder the pins to the stripboard.
Next, carefully remove the plastic
from the pin-strip on the USB BoB
side by sliding it upwards. Now you
can solder the pins to the top side of
the USB BoB. This process ensures
that the BoB is fixed down flush onto
the strip-board. See Fig.21 and Fig.23.
Finally, solder two wire-link off-cuts
into hole positions VV32 and VV36.
These add strength by holding the
USB BoB down onto the stripboard.
9. Solder the power button (S1) into
place. (Remember to make track cut
first – see Fig.20.)
10. Solder the 10kΩ pull-down resistor
(R1) into place.
11. Solder the 2-way jumper link (JP8)
into place. For now, do not insert
the jumper link. (Remember to make
track cut first – see Fig.20.)
12. Solder the two modified 4-way pinstrips (JP1 and JP2) into position.
Insert them from the upper side so
the pins point downwards. Once
soldered, slide on the two modified
4-way sockets, (JS1 and JS2). These
sockets will be soldered directly
to the two motors later (once the
daughterboard is mounted onto the
acrylic chassis).
13. Solder the 13-way pin-strip (JP5) and
the 14-way pin-strip (JP6) into place.
These are both downward facing and
will ultimately allow the MKC plus
Bluetooth module to be attached to
the underside of the robot, as shown
in Fig.22 and Fig.23.
14. Solder the two 6-way sockets (JS3 and
JS4) along with the 14-way socket
(JS5) into position. These will allow
MIWM modules to be plugged into
the robot from above, such as the
TFT module.
That completes the assembly of the
daughterboard for now. If you have
followed the above steps, then the LiPo
Charger/Booster module (MOD3) will
not be installed. This is important as we
will test the daughterboard first before
we solder MOD3 into place. Once again,
do a thorough visual check and correct
any issues. The circuit is not complex so
there really isn’t much that can go wrong
other than accidental shorts between
tracks, or missed track-cuts. I recommend
you take a break now, and come back to
it another time and do one final check
before moving on.
51
MOD2 mounted
flush with stripboard
Fig.23. The MKC and Bluetooth module correctly attached provides sufficient ground clearance (even though it looks close!).
Mounting the daughterboard
We will now mount the daughterboard
onto the chassis so that we can test that
the motors operate correctly. Begin by
taking the Bluetooth (BT) module and
inserting it through the chassis from
below. You should find that the four
Bluetooth sockets will pass through
slots SL5, SL6. SL7 and SL8. If not,
then you may just need to ‘assist’ them
through. Once in place, offer up the
daughterboard aligning it with the four
nylon screws. You now need to line up
the two rows of downward facing pins
(JP5 and JP6) and insert them into the
BT module. You may also need to bend
the two pairs of 4-way motor connectors
(JS1 and JS2) through slots SL1 and SL2
in order for everything to fit correctly.
Once in place, use the four remaining
nylon nuts to fix the daughterboard to
the chassis. Tighten these nuts fully.
Next, remove the BT module and you
should then see that the daughterboard
pins are reasonably central when viewed
from below, as shown in Fig.19. Note
that the longer slot SL3 is not currently
being used, so ignore the pins that you
can see in SL3 in Fig.19.
Now we need to solder the two motors
to the two modified 4-way sockets (JS1
and JS2) that should be poking through
slots SL1 and SL2. Refer to Fig.15 to see
how the end result should look. The
sockets can be re-positioned as they are
currently only slid onto JP1 and JP2 on
the daughterboard. An important point
(if using ‘extended’ shaft motors) is not
to let the plastic housings on JS1 and
JS2 touch the motor shaft. If they do,
then the motor(s) won’t turn correctly.
So go ahead and position the sockets as
required, and then solder them carefully
to the motors. Be careful not to slip with
the soldering iron as this could melt the
52
plastic on the back of the motor (yes, I
did just that on an early version). Cut off
any excess socket contact so that you end
up with something similar to that shown
in Fig.15. Now we are in a position to
test the motors.
Testing the motors
At this stage, you should have the MRB
daughterboard firmly attached to the
chassis. The LiPo Charger/Booster module
should not be installed, and no MIWM
hardware should be attached (not even
the MKC or BT modules).
For the motor test, a 5V power source
is required along with six (male-to-male)
jumper wires, and a small breadboard
(or equivalent).
The idea behind this test is to power
the daughterboard with the 5V supply,
and then connect 0V and 5V DC to one
pair of input pins on the motor driver
module (eg, IN1 and IN2 on MOD1). If
everything is OK, then this will spin
one of the MRB tracks in one direction.
Swapping the polarity to IN1 and IN2
should reverse the motion. The test is
then repeated by supplying 5V DC to the
other pair of input pins (IN3 and IN4),
which should spin the other track. Again,
the spin direction is determined by the
polarity applied to the input pins.
You can use your MKC as the 5V power
source by ‘tapping into’ the two end pins
on the 6-way socket (0V closest to USBmicro socket). Use two jumper wires to
connect 0V and 5V from the MKC to the
breadboard, and then use two more to feed
0V and 5V (from the breadboard) to the
0V and 5V positions on JS4 – see Fig.18.
Now power up your MKC as normal
and check that its power LED is lit. For
clarity, there is no need to launch your
terminal app – you simply need to power
up your MKC. Your daughterboard is now
powered up. Depending on the version
of MOD1, you may see an LED on the
motor module light up.
If the MKC’s power LED is not lit then
there is a problem; check its power source,
and also the correct connection of the
four jumper wires.
With the MKC’s power LED lit, the
remaining two jumper wires are used
to supply 0V and 5V DC to one of the
two input pairs on the motor module.
Use one jumper wire to supply 0V (from
the breadboard) to pin 4 on JS5 (IN1 on
MOD1), and the other to supply 5V (from
the breadboard) to pin 9 on JS5 (IN2 on
MOD1). This should result in one track
rotating so you will need to hold the robot
off your workbench. If a track doesn’t
rotate then you will need to check for
shorts, all jumper wire connections, and
the 12 solder joints on MOD1.
When you have achieved successful
movement of a track swap the jumper
wire to pins 4 and 9 on JS5, and check
the same track now rotates in the opposite
direction. Once this is functioning
correctly, you can remove the wires
from pins 4 and 9, and carefully insert
them into pins 5 and 10. Repeat the test
to ensure the other track can rotate in
both directions. Once complete, power
down your MKC, and remove all six
jumper wires.
Take your time and all will be well,
but if you’re totally stuck, then send me
an email and attach a high-resolution
photo of the underside (track-side) of
your daughterboard. This will mean
dis-assembling your robot by undoing
the four nylon nuts, and then carefully
unplugging the daughterboard from the
two motor sockets.
When you have successfully completed
the motor test you can proceed to the
final assembly task.
Practical Electronics | June | 2020
Fig.24. The Micromite Robot Buggy (with the TFT module attached) running the
MicromiteRobotBuggy_Demo1 program.
Final assembly
We will soon solder the LiPo charger/
booster module into place but before
doing that, let’s quickly check that it
works. Connect the LiPo battery to the
LiPo module, being careful to ensure you
insert the battery’s 2-pin JST connector
the correct way round. The JST connector
is shaped in such a way that the battery
can only be inserted in one orientation.
As a sense check, the battery’s black
lead will be closest to the corner of the
module. On inserting the battery, the
module’s power LED (typically a blue
one) should light up. This confirms
the module is functioning correctly. If
the LED does not light up, be sure that
the module is not sitting on anything
conductive! If the LiPo is ‘dead’ then
that could be the issue; however, LiPo
batteries typically have protection circuit
built in that prevents them totally running
flat. If the LiPo module’s power LED
doesn’t light up, plug a 5V PSU directly
into the micro-USB socket on the charger
module (this is a charging input). On
doing this, you should see the recharging
LED illuminate (orange or green). If so,
then let the battery recharge for a short
while. If there is still no LED that lights
up then you will need to check the battery
is inserted correctly. If you still have
problems then try another LiPo battery.
Once you see the LiPo module’s power
LED light up, carefully remove the LiPo
battery. Do not pull on the delicate battery
leads to do this – they are very delicate!
With the battery removed, go ahead and
solder the module onto the five protruding
pins on the 8-way pin-strip (JP9) on the
Practical Electronics | June | 2020
daughterboard (refer to Fig.18, 20 and
21 to confirm placement). Now install
the jumper-link onto the 2-way pinheader (JP8).
With the LiPo module installed, and
the jumper-link in place, carefully reconnect the LiPo battery. Next, do a quick
power test by pressing the power button
(S1). Upon pressing the button, the LiPo
module’s power LED should light up
indicating that 5V power is output from
MOD3. However, as soon as you release
the power button, the power LED should
turn off. With the button released (and
the MOD3 power LED off), remove the
2-way jumper link and check the MOD3
LED comes back on. If any of these tests
fail then you will need to check all the
tracks concerned with power circuit –
use the stripboard layout in Fig.20 to
assist with this.
Once both the motor circuit, and the
power circuit have been successfully
tested, plug the Bluetooth module
into your MKC, and connect them to
your robot by plugging them into the
underside of the robot (Fig.22). Ensure
that these are pushed fully into place
so that there is sufficient clearance from
any flat surface that the robot is placed
onto (Fig.23).
Next, carefully plug in the TFT module
ensuring that all the pins on the TFT
module insert into the sockets (JS3, JS4,
and JS5) correctly. Finally, remove the
2-way jumper link to power up the MRB.
Robot demo software
Your Micromite robot buggy is now ready
to be tested from your remote computer
by using the demo program that we have
written. The program allows you to control
(ie, move) the robot buggy by prompting
you to enter a direction, and a duration.
The program also confirms that you still
have wireless remote access between
your terminal app and your ‘mobile’
MKC. You need to download the file
MicromiteRobotBuggy_Demo1.txt from
the June 2020 page of the PE website.
With the power-jumper link off, the
TFT module inserted, and with the LiPo
battery plugged into the LiPo Booster/
Charger module, install the code onto
your MKC and run the program. If all is
well you should hear an initial beep (if
you have the piezo sounder installed on
your TFT module), and you should also
see a colourful ‘MICROMITE ROBOT
BUGGY’ message on the TFT. In your
terminal app you should be prompted to
enter a direction in the form: (F)orward,
(B)ack, (L)eft, (R)ight, (O)FF. Press the
‘F’ key (Enter) and then enter a lowvalue duration such as 2. On pressing
the Enter key your robot buggy should
move forwards a short distance, and
then stop. Upon completion of the move,
you should hear a short beep from the
piezo. You should also be able to see the
direction and duration value on the TFT
screen (as shown in Fig.24). Check the
other three directions (B, L and R) also
function as expected. Now return the
jumper link to JP8. Finally, select the ‘O’
option and check that the robot turns off.
This is only a simple test demo to
check the basics – if any of the tests
fail, then take your time checking
things over. Remember that all we have
essentially done is add a battery, and a
set of wheels, to your existing (working)
MKC, Bluetooth, and TFT modules. If you
have successfully reached this point then
congratulations – you have successfully
assembled your Micromite Robot Buggy!
Next Month
Having assembled the robot chassis
module, you now have a basis on which
to add some other features (and hence
add some personality to your robot). So
next month we will show you how to add
some animated eyes (in the form of two
8×8 LED matrix modules). In addition,
we will add an IR receiver to control
various robot features from an IR remote.
In the meantime, why not write some
code to make your robot automatically
follow a sequence of steps (movements
and turns) so that it moves around on a
defined path. Then make it repeat this
path over and over. Have Fun!
Questions? Please email Phil at:
contactus<at>micromite.org
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