Jump To: Project Overview Bill of Materials Gems of Wisdom
In brief, the goal of this project was to design a
watercraft and helm that would communicate with each other given a specified communications
protocol. The craft is operated by remote control at the helm and would have to
move around in relatively shallow water. The craft must also be able to deliver
water (i.e. shoot) into the target bucket of the opposing team. For more information
regarding the project specifications, please see project-desc. For more information
on the communication protocol designed, see the student-produced document comm-spec.
Our solution was to make an
extremely sea-worthy yet modular watercraft to make splitting up work obvious
and physically simple. Our idea for the helm was to make it a model replica of
our boat, with user controls closely related to the actuation of pieces of the
craft:
- Speed of the propeller is
controlled by the pitch of the helm
- Rudder angle is controlled
by the roll of the helm
- Turret rotation is
controlled by rotating a turret on the helm
- Pump power is controlled
by a Fire! button and a dial on the helm
A quick glance at our helm
and watercraft:
THE HELM! THE BOAT!
|
Item |
Source |
Quantity |
Price per
unit |
Total |
|
Craft |
|
|
|
|
|
PIC 16F690 |
TA Shop |
3 |
$2.00 |
$6.00 |
|
LEDs (red and blue) |
TA Shop |
1 |
$2.30 |
$2.30 |
|
IRLZ34N |
TA Shop |
1 |
$0.30 |
$0.30 |
|
L293B Motor driver |
TA Shop |
2 |
$2.95 |
$5.90 |
|
LM 6144 OP Amp |
TA Shop |
1 |
$0.00 |
$0.00 |
|
74HC14 comparator with
Hysteresis |
TA Shop |
1 |
$0.35 |
$0.35 |
|
Xbee Module |
TA Shop |
1 |
$0.00 |
$0.00 |
|
DC Motor |
JM Hobby |
1 |
$18.00 |
$18.00 |
|
Rule Brand 800 GPH Bilge
pump model 20R |
West marine |
1 |
$34.99 |
$34.99 |
|
Servo Motor |
Jameco |
1 |
$12.00 |
$12.00 |
|
Stepper Motor |
TA Shop |
1 |
$2.00 |
$2.00 |
|
Tupperware |
Target |
2 |
$5.00 |
$10.00 |
|
Rudder and tie rod |
JM hobby |
1 |
$10.00 |
$10.00 |
|
Propeller and shaft |
JM Hobby |
1 |
$5.00 |
$5.00 |
|
water bottles |
Target |
4 |
$1.00 |
$4.00 |
|
Pink Foam |
US Foam |
1 |
$10.00 |
$10.00 |
|
various resistiors,
transistors, capacitors, etc, |
|
|
|
$2.00 |
|
|
|
|
Subtotal |
$122.84 |
|
|
|
|
|
|
|
Helm |
|
|
|
|
|
PIC 16F690 |
TA Shop |
2 |
$2.00 |
$4.00 |
|
Accelerometer |
Digikey |
1 |
$8.86 |
$8.86 |
|
3 digit LED display |
Jameco |
1 |
$2.39 |
$2.39 |
|
Limit switches |
Jameco |
2 |
$1.38 |
$2.76 |
|
Shift register sn74hc164n |
jameco |
1 |
$0.75 |
$0.75 |
|
BCD decoder sn74ls47n |
jameco |
1 |
$0.92 |
$0.92 |
|
LM 6144 OP Amp |
TA Shop |
1 |
$0.00 |
$0.00 |
|
LEDs (red and blue) |
TA Shop |
2 |
$2.30 |
$4.60 |
|
Xbee Module |
TA Shop |
1 |
$0.00 |
$0.00 |
|
Pink Foam |
US Foam |
1 |
$10.00 |
$10.00 |
|
Tupperware |
Target |
2 |
$5.00 |
$10.00 |
|
Water bottles |
Target |
4 |
$0.75 |
$3.00 |
|
various resistiors,
transistors, capacitors, etc, |
|
|
|
$2.00 |
|
|
|
|
Subtotal |
$49.28 |
|
|
|
|
|
|
|
|
GRAND TOTAL = |
$172.12 |
||
- Be careful
to keep the ground returns from your actuators separate from the logic
ones. Or at the very least keep noise in
mind as a possible source of logic errors.
- If you are
going to use SPI, be sure that you do everything possible to make your signal
perfect. If you split it, use buffers to
ensure that both micros get the signal.
If you need to shift logic levels, use a comparator to ensure crisp
edges.
- Put a
pause at the beginning of your program to allow power to ramp up before you
begin initializations to make sure everything is set correctly
- Talk about
scheduling and planning really early so everyone’s one the same page
- Try to
design the structures for quick disassembly, reassembly
- Give each
person enough responsibility so that they are never without work to do