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

2. AIR FORCE 1

3. 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

4. Sensor
L M R
State Machine
Controller
BASYS 2 BOARD D D
n bits
n bits
Left PWM
Right PWM T T
Motor Driver

5. 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 L2 L1 L0
3-bit
Value R2 R1 R0

6. 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%

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

8. PWM Demo

9. PWM Generator Circuit (e.g. Left motor)GT EQ LT
3-bit
Comparator X2 X1 X0 Y2 Y1 Y0
Left
PWM
RCO
LD’
CLR’
3-bit
Counter T P
QC QB QA
C B A 1
Clk
L2 L1 L0
PWM
Control
Value
3-bit value
From
State
Machine

10. PWM Generator Circuit Clk QA QB QC X Cnt Y Cntl G E L

11. PWM Generator Circuit Clk QA QB QC X Cnt Y Cntl G E L PWM

12. PWM Generator Circuit Given: Fclk and n-bit Counter/Comparator
X Cnt
Y Cntl G E L
PWM
Given: Fclk and n-bit
Counter/Comparator
Fg = Fclk/2n
Fe = Fclk/2n
Fl = Fclk/2n
Fl+e = Fclk/2n
DCg = (2n - Ycntl-1)/2n
DCe = 1/2n
DCl = Ycntl/2n
DCl+e = (Ycnlt + 1)/2n

13. PWM Generator fx > GT 3-bit cntr 3-bit Comparator EQ LT Left
5KHz
Left
3-bit
Value
Right
Both 3-bit Values are generated by State Machine to control PWM Duty Cycle for each Motor L2 L1 L0 R2 R1 R0
Right
PWM
5KHz
How is Fx determined?

15. PWM Generator Circuit Clk QA QB QC X Cnt Y Cntl G E L PWM