PIC18F85K22-I/PT Microchip Technology, PIC18F85K22-I/PT Datasheet - Page 393

• Manufacturer Part Number: PIC18F85K22-I/PT
• Description: IC, 8BIT MCU, PIC18F, 64MHZ, TQFP-80
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F85K22-I/PT

• Controller Family/series: PIC18
• No. Of I/o's: 69
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 64MHz
• No. Of Timers: 8
• Core Size: 8 Bit
• Program Memory Size: 32KB
• Core Processor: PIC
• Speed: 64MHz
• Connectivity: EBI/EMI, I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 24x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-TQFP
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

EXAMPLE 27-2:
 2009-2011 Microchip Technology Inc.
#include "p18cxxx.h"
#define COUNT 500
#define DELAY for(i=0;i<COUNT;i++)
#define RCAL .027
#define ADSCALE 1023
#define ADREF 3.3
int main(void)
{
//assume CTMU and A/D have been setup correctly
//see Example 25-1 for CTMU & A/D setup
setup();
CTMUCONHbits.CTMUEN = 1;
}
int i;
int j = 0; //index for loop
unsigned int Vread = 0;
double VTot = 0;
float Vavg=0, Vcal=0, CTMUISrc = 0;
for(j=0;j<10;j++)
{
}
Vavg = (float)(VTot/10.000);
Vcal = (float)(Vavg/ADSCALE*ADREF);
CTMUISrc = Vcal/RCAL;
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;
CURRENT CALIBRATION ROUTINE
//@ 8MHz = 125uS.
//R value is 4200000 (4.2M)
//scaled so that result is in
//1/100th of uA
//for unsigned conversion 10 sig bits
//Vdd connected to A/D Vr+
//float values stored for calcs
//Enable the CTMU
//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
PIC18F87K22 FAMILY
DS39960D-page 393