1. Sensor Board and Driver Board
Krisys
Technology
Krisys Robot
Sensor Board and Driver Board
Dr. Joseph A. Morgan, P.E.

2. Krisys Functional Block Diagram
Battery
3.3V
Reg 5V
Power
Krysis Control Board
Intelligence
BASYS2
FPGA
SensorR 1
SensorM
SensorL 2 3
Sensor Board
Mode_select
3.3V
GND
Dual
H-Bridge
L_Motor_T
L_Motor_D
R_Motor_T
R_Motor_D
LED
LED_diag L
Motor
R Motor

3. Electronics Krisys Sensor Board (KSB) Krisys Motor Driver Board (KMDB)
Inductive sensors – analog input
Amplifiers
Analog comparators
Digital output (active low)
Krisys Motor Driver Board (KMDB)
Voltage regulators 3.3V and 5V
Dual H-Bridge motor driver
Not Populated

4. KSB
Surface mount and through-hole technology

5. Faraday’s Law of Induction
If a changing magnetic flux flows through a coil of wire, a voltage will be induced in the coil.
As you pass a bar magnet through a coil, this creates a changing magnetic field.
How else can we create a changing magnetic field?

6. Magnetic Sensors
Magnetic Field
Voltage
Current
+ Voltage -
Area

7. Sensor Circuit Active Low Digital Out 0 => signal 1 => no signal
Adjustable

8. KSB Schematic

9. Systematic Testing, Debugging, Optimizing
Correct information from the sensor board
101 On Middle Sensor
001 Between Left and Middle Sensor
011 On Left Sensor
100 Between Right and Middle Sensor
110 On Right Sensor
Control of the wheels
Forward Reverse
L-Turn R-Turn
Use Test Circuits to sense and control
Left Middle Right

10. Attributes of Digital Signal
Vmax
Vmin
Amplitude (Voltage)
Vmin, Vmax
Amplitude = Vmax – Vmin
Period (seconds)
Time to repeat
Frequency (Hertz)
1/period
Duty Cycle (percentage)
Time ON / period
period
(sec)
p = 1ms, f = 1000 Hz
Time ON
(sec)
ton = 0.2ms
p = 1ms
dc = 20%

11. Average Voltage
Vmax
Vavg = f(dc)
Vavg
Vmin
Vmax
Vavg
Vmin

12. PWM Demo

13. Sensors 1 On Tape Off Tape L M R Condition ? 11
On Tape
Off Tape L M R
Condition ? 1
Slightly Off Tape to Right
Way Off Tape to Right
Slightly Off Tape to Left
On Tape
Way Off Tape to Left
Completely Off Tape

14. Control > L M R A<B<C<D State Machine L M R 3-bit Value
Condition
Action
Left D.C.
Right D.C. ? 1
Slightly Off Tape to Right
Easy Left A B
Way Off Tape to Right
Hard Left C
Slightly Off Tape to Left
Easy Right
On Tape
Go Straight
Way Off Tape to Left
Hard Right
Completely Off Tape
Loop
A/D
D/A
State Machine
> L M R
Mode
Mater
Clock
3-bit
Value
3-bit
Value

15. State Machine Determine: How to get into each State
What are the outputs generated when in each State

16. Frequency and Duty Cycle
3-bit
cntr fx
>
Cntr GT EQ LT
3-bit Comparator
How should these be combined?
Want to be able to generate variable Duty Cycle up to and including 100%. Frequency needs to be 5kHz to Motors.
3-bit
Value
Both 3-bit Values are generated by State Machine to control PWM Duty Cycle for each Motor
How is Fx determined?

17. Assignment
Provide a computer-generated block diagram of wiring connections necessary to properly implement your Krisys Robot. Clearly show in your diagram:
Battery
Krisys Motor Power Board
Krisys Sensor Board
Basys2 FPGA Board
All interconnections including Connector/Pin#
Due – Monday at 10:00 AM
Will be a quiz grade equivalent