PIC18F27J53T-I/SO Microchip Technology, PIC18F27J53T-I/SO Datasheet - Page 430

• Manufacturer Part Number: PIC18F27J53T-I/SO
• Description: 28-pin, USB, 128KB Flash, 4KB RAM, 12 MIPS, 12-bit ADC, NanoWatt XLP 28 SOIC .30
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 18Fr

Specifications of PIC18F27J53T-I/SO

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 48MHz
• Connectivity: I²C, LIN, SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 22
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Ram Size: 3.8K x 8
• Voltage - Supply (vcc/vdd): 2.15 V ~ 3.6 V
• Data Converters: A/D 10x10b/12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 3.8 KB
• Interface Type: I2C, SPI, USART
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 16
• Number Of Timers: 8
• Operating Supply Voltage: 2.15 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

PIC18F47J53 FAMILY
EXAMPLE 27-2:
DS39964B-page 430
#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)
{
}
setup();
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.CTMUEN = 1;
CTMUCONLbits.EDG1STAT = 0;
CTMUCONLbits.EDG2STAT = 0;
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
Preliminary
//drain charge on the circuit
//@ 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
//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
//Enable the CTMU
// Set Edge status bits to zero
//assume CTMU and A/D have been setup correctly
//see Example 25-1 for CTMU & A/D setup
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