Microchip Technology dsPIC30F - Page 401

© 2004 Microchip Technology Inc. DS70064C-page 17-25
Section 17. 10-bit A/D Converter
10-bit A/D
Converter
17
Figure 17-11: Converting 1 Channel, Auto-Sample Start, Conversion Trigger Based Conversion Start
Example 17-6: Converting 1 Channel, Auto-Sample Start, Conversion Trigger Based
Conversion Start Code
ADCLK
SAMP
ADCBUF0
TSAMP
TCONV
BSF ADCON1,ASAM Instruction Execution
TCONV
TSAMP
ADCBUF1
DONE
Conversion
Trigger
ADPCFG = 0xFFFB; // all PORTB = Digital; RB2 analog
ADCON1 = 0x0040; // SSRC bit = 010 implies GP TMR3
// compare ends sampling and starts
// converting.
ADCHS = 0x0002; // Connect RB2/AN2 as CH0 input ..
// in this example RB2/AN2 is the input
ADCSSL = 0;
ADCON3 = 0x0000; // Sample time is TMR3, Tad = internal Tcy/2
ADCON2 = 0x0004; // Interrupt after 2 conversions
// set TMR3 to time out every 125 mSecs
TMR3 = 0x0000;
PR3 = 0x3FFF;
T3CON = 0x8010;
ADCON1bits.ADON = 1; // turn ADC ON
ADCON1bits.ASAM = 1; // start auto sampling every 125 mSecs
while (1) // repeat continuously
{
while (!IFS0bits.ADIF); // conversion done?
ADCValue = ADCBUF0; // yes then get first ADC value
IFS0bits.ADIF = 0; // clear ADIF
} // repeat