Mixed Signal VlSI Technology To Design Programmable System On Chip To Measure Environmental Parameters Of Polyhouse. By A. S. Powar

2. A . S. Powar, S. K.Tilekar and
B.P. Ladgaonkar.
VLSI Design and Research Center
Post Graduate Department of Electronics
Shankarrao Mohite Mahavidyalaya, Akluj
Tal - Malshiras , Dist. - Solapur – 413 101

3. • Introduction
– Origin of the Problem
– PSoC
• Designing of the System
– Hardware & Software Co-design
• Result and Discussion
• Conclusion

4. WHY HIGHTECH POLYHOUSE TECHNOLOGY ?

5. Temperature
Controlling Unit
Humidity
Sensor
SY-HS-220
Temperature
Sensor
AD 590
Microcontroller
AVR
Atmega8L
Power
Supply
+5V
+9V
-9V
Offset Voltage
Compensator
(741)
Liquid Crystal
Display
(16x2 lines)
In System
Programming
Instrumentation
Amplifier
AD 620
Instrumentation
Amplifier
AD 620
Humidity
Controlling
Unit
Phototransistor
BPW34
Instrumentation
Amplifier
AD 620

6. ADC FPGABuffer Amplifier
Weak
analog
signal

7. P rogrammable
S ystem
o n
C hip
PSoC
Weak
analog
signals

8. CO2 sensor (MG-
811) &
Humidity sensor
(SY-HS-220)
PSoC 1 Device
CY8C29466 -
24PXI
LCD

9. o Highly precise and
reliable.
o Exhibit linearity over
30%Rh to 95 % Rh.
o The humidity sensor is
of Capacitive type.
o Provides DC output
voltage.
o Good sensitivity and
selectivity to CO2 .
o Low humidity and
temperature
dependency.
o Long stability and
reproducibility.

10. Overall chemical reaction：Li2CO3 + 2Na + = Na2O + 2Li + + CO2
EMF = Ec - (R x T) / (2F) ln (P(CO2))
Where, P(CO2) - CO2 partial Pressure, Ec - Constant Volume, R - Gas
Constant volume, T - Absolute Temperature (K), F- Faraday constant

11. CO2 sensor (MG-
811) &
Humidity sensor
(SY-HS-220)
PSoC 1 Device
CY8C29466 -
24PXI
LCD

12. Inputs :
 Each pin can sink 25mA
 Programmable filters
 Flexible sensor interface I/O
 3 types of ADCs, up to 4
Processing :
Outputs :
 Each pin can source 10mA
 Up to 16 PWMs, Timers, Counters
 Up to 9-bit DACs, 14-bit ADCs
Support Functions :
 EEPROM
 Sleep Options
 Watch Dog Timer
 Low voltage detect
 Fast M8 Microcontroller Core
 Multiply Accumulate

16. ADCINCVR
LCD
PGA

17. Block Diagram of ADCINCVR

18. Vo =(VIN –VGND).(Ra/Ra+Rb)+VGND

19. I = V/R
Q = CV
I average = Q/T = Qfs = CVfs
R equivalent = V/I average = 1/Cfs

23. Execute boot program:
--initialise general purpose resources;
--configure application specific modules;
--initialise run time environment;
--disable interrupt;
call main application routine;
Void main()
{
Start system timers;
Initialise application specific modules;
Initialise global variables;
Initialise application specific channels;
Enable interrupts;
While(1)
{
Wait for events(Enabled interrupts);
Read values from input channels;
Execute control
procedure & compute
actuation data;
output actuation data to output
channels;
}
}
B) Application programme routine
A) Boot programme algorithm

24. Start
Initialization of
all modules
Get ADC reading
Get reading for CO2
Display reading
Convert in ASCII
Calibrate data for
Humidity
If
count<0x65(
200mv)
R
Display as DetectedDisplay as Undetected
NoYes
Software Design Flow Of
Our System

27. y = 0.0288x + 11.315
0
20
40
60
80
100
120
0 1000 2000 3000 4000
Series1
Linear (Series1)
Humidity(%Rh) Output(mV)
30 794
35 860
40 958
45 1092
50 1258
55 1458
60 1709
65 1894
70 2064
75 2224
80 2383
85 2547
90 2729
95 2935

28. Comparision
Sr.
No.
Parameter AVR
ATmega 8L
System
CY8c29466 PSoC
system
1 Power 300mW 130mW
2 Cost(₹) X X-400
3 Time 3-4 days 2-3 hours

29. System is designed for measurement of humidity and CO2 gas.
The humidity observations shown by the system are highly reliable and
precise. Moreover, the presence of CO2 gas is also exhibited by the
present system. System works successfully and gives the data of humidity
and CO2 very precisely.

30. o Particularly for measurement of carbon dioxide (CO2)
gas concentration, the calibration in the respective
units is required. However, presently due to
unavailability of CO2 gas chamber the calibration of
carbon dioxide gas concentration is left as future
work.
o Implementation of the system for mote.

31. References:
1.Introduction to Mixed-Signal, Embedded Design- Alex N. Doboli and
Edward H. Currie.
2. CYPRESS MICROSYSTEMS “PSoC TM The Configurable Mixed Signal array
With on-chip controller.
3. An Architecture for a Configurable Mixed-Signal Device Monte Mar, Member,
IEEE, Bert Sullam, Member, IEEE, and Eric Blom IEEE JOURNAL OF
SOLID-STATE CIRCUITS, VOL. 38, NO. 3, MARCH 2003.
4. P.E. Allen and D.R. Holberg, CMOS Analog Circuit Design – 2nd Ed., Oxford
University Press, 2002.
5. R.J. Baker, H.W. Li and D.E. Boyce, CMOS Circuit Design, Layout, and
Simulation, IEEE Press, 1998