MA160014 Microchip Technology, MA160014 Datasheet - Page 324

• Manufacturer Part Number: MA160014
• Description: MOD PLUG-IN 44PIN PIC18LF45K22
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of MA160014

• Accessory Type: Plug-In Module (PIM) - PIC18LF45K10
• Product: Microcontroller Modules
• Data Bus Width: 8 bit
• Core Processor: PIC18LF45K22
• Interface Type: I2C, SPI
• Operating Supply Voltage: 1.8 V to 5.5 V
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PICDEM PIC18 Explorer, DM183032
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PIC18(L)F2X/4XK22
EXAMPLE 19-3:
DS41412D-page 324
#include "p18cxxx.h"
#define COUNT 25
#define ETIME COUNT*2.5
#define DELAY for(i=0;i<COUNT;i++)
#define ADSCALE 1023
bits
#define ADREF 3.3
#define RCAL .027
int main(void)
{
//assume CTMU and A/D have been set up correctly
//see Example 25-1 for CTMU & A/D setup
setup();
CTMUCONHbits.CTMUEN = 1;
CTMUCONLbits.EDG1STAT = 0;
CTMUCONLbits.EDG2STAT = 0;
}
int i;
int j = 0;
unsigned int Vread = 0;
float CTMUISrc, CTMUCap, Vavg, VTot, Vcal;
for(j=0;j<10;j++)
{
}
Vavg = (float)(VTot/10.000);
Vcal = (float)(Vavg/ADSCALE*ADREF);
CTMUISrc = Vcal/RCAL;
CTMUCap = (CTMUISrc*ETIME/Vcal)/100;
CTMUCONHbits.IDISSEN = 1;
DELAY;
CTMUCONHbits.IDISSEN = 0;
CTMUCONLbits.EDG1STAT = 1;
DELAY;
CTMUCONLbits.EDG1STAT = 0;
PIR1bits.ADIF = 0;
ADCON0bits.GO=1;
while(!PIR1bits.ADIF);
Vread = ADRES;
PIR1bits.ADIF = 0;
VTot += Vread;
CAPACITANCE CALIBRATION ROUTINE
Preliminary
//@ 8MHz INTFRC = 62.5 us.
//time in uS
//for unsigned conversion 10 sig
//Vdd connected to A/D Vr+
//R value is 4200000 (4.2M)
//scaled so that result is in
//1/100th of uA
//index for loop
//Enable the CTMU
// Set Edge status bits to zero
//drain charge on the circuit
//wait 125us
//end drain of circuit
//Begin charging the circuit
//using CTMU current source
//wait for 125us
//Stop charging circuit
//make sure A/D Int not set
//and begin A/D conv.
//Wait for A/D convert complete
//Get the value from the A/D
//Clear A/D Interrupt Flag
//Add the reading to the total
//Average of 10 readings
//CTMUISrc is in 1/100ths of uA
 2010 Microchip Technology Inc.