CY8CKIT-014 Cypress Semiconductor Corp, CY8CKIT-014 Datasheet - Page 24

• Manufacturer Part Number: CY8CKIT-014
• Description: KIT DEV PSOC5 FIRST TOUCH
• Manufacturer: Cypress Semiconductor Corp
• Series: PSoC® 5, FirstTouch™r
• Type: MCUr

Specifications of CY8CKIT-014

• Contents: Board, Battery, Cable, CD, Documentation, Wire
• Processor To Be Evaluated: CY8C5588AXI
• Processor Series: CY8C55
• Interface Type: USB
• Operating Supply Voltage: 9 V
• Silicon Manufacturer: Cypress
• Core Architecture: PSoC
• Silicon Family Name: PSoC
• Kit Contents: Board, CD, Cable
• Features: Programmable System-on-chip Design Methodology And Architecture
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: CY8C55
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 428-3039

Example Projects
4.3.1.1
24
Figure 4-13. Temperature Sensor Project Flowchart
Temperature Sensing Design Principle
As shown in
resistor on one side and the thermistor on the other to estimate the thermistor resistance. The
temperature calculations are as accurate as the resistance measurement of the thermistor.
Figure 4-14. Temperature Sensing Design Principle
R
This setup significantly removes gain and offset errors from the resistance calculation.
The analog voltage output from the divider is converted to a digital signal using the ADC on the
PSoC. To gain additional accuracy, the voltage at the input side of the divider is also measured. The
resistor value is calculated using the ratio of the voltages across the two resistors in the resistor
ladder.
In this equation, V
Offset errors, if any, are removed due to subtraction of the two measured voltages. The ratio of these
two values removes the measurement path gain error. The error due to the reference resistor is
reduced by using a precision resistance in series with the thermistor.
Thermistor
R
Ref
Compute temperature
Change temperature
If switch is pressed?
V
display mode
V
2
V
0
1
Yes
M
Boot
Start
A
U
X
Figure
Yes
VDC
Blocks
2
ADC
= 0 (Ground voltage)
4-14, the design for temperature sensing uses a voltage divider with a precision
PSoC
No
CY8CKIT-014 PSoC 5 FirstTouch Starter Kit Guide, Spec. # 001-57708 Rev. *A
Rthermistor = Rref * (V
Calculate character offset
Update the raster display
in the string and update
accelerometer Y axis
Read and process
String complete?
LED display
data array
voltage
1
-V
No
2
/V
0
-V
1
)