AMICUS18-COMPANION-SHIELD AMICUS, AMICUS18-COMPANION-SHIELD Datasheet - Page 38

• Manufacturer Part Number: AMICUS18-COMPANION-SHIELD
• Description: Amicus18 Companion Shield
• Manufacturer: AMICUS

Specifications of AMICUS18-COMPANION-SHIELD

• Silicon Manufacturer: Microchip
• Core Architecture: PIC
• Core Sub-architecture: PIC18
• Features: USB Interface, In Circuit Serial Programming Interface
• Kit Contents: Board
• Silicon Family Name: PIC
• Silicon Core Number: PIC18F25K20
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: PIC18F25K20 Microcontroller

The circuit for the temperature layout is shown below:
A program to display the the values produced from the thermistor on the serial terminal is shown below:
' Display the value of an NTC thermistor on the serial terminal
' The thermistor is connected To AN0 (Channel 0 of the ADC)
'
' Open the ADC:
'
'
'
'
'
'
Once the program has been loaded into the Amicus18 board, open the serial terminal and connect to
the Amicus18’s com port:
The display shows the decrease in voltage with the increase in temperature when a finger covers the
thermistor, and is then removed. As can be seen, a thermistor is quite sensitive.
Crownhill AssociatesLimited 2009 - All Rights Reserved
Include
Dim ThermistorIn As Word
OpenADC(ADC_FOSC_32 & ADC_RIGHT_JUST & ADC_0_TAD, ADC_REF_VDD_VSS, ADC_1ANA)
While 1 = 1
Wend
ThermistorIn = ReadADC(0)
HRSOut
DelayMS 500
"ADC.inc"
"Thermistor =
Fosc set for Fosc/32
Right justified for 10-bit operation
Tad value of 0
Vref+ at Vcc : Vref- at Gnd
Make AN0 an analogue input
Amicus18 Companion Shield
Version 1.0
AN4/AN5
AN3/RA3
AN2/RA2
AN1/RA1
AN0/RA0
", Dec ThermistorIn, 13
PortA
Power
GND
GND
RA4
3V3
Vin
Rst
5V
Thermistor
' Load the ADC macros into the program
' Create a variable to hold the 10-bit ADC result
Room Temperature (Approx 21 degrees Centigrade)
Finger Covering Thermistor (Increase in Temperature)
Finger Removed from Thermistor (Decrease in Temperature)
-t
10K
Ω
37
LED
47
Ω
' Create an infinite loop
' Read the ADC on AN0
' Delay for half a second
' Do it forever
' Display the ADC value
Power
PortB
GND
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0
06-10-2009