Instant Interrupts - Revisited

[Darrel Taylor]

sougata,

I'm glad it's working out for you. And yes, it is more managable. Kinda the whole idea behind it.

Squibcakes,

No, it doesn't work that way.

The AD_INT is fired on the completion of an A/D conversion. Not when the value changes.

So, in your AD_INT handler, you could test to see if the recent A/D reading differs from the previous A/D value. If it does, call a subroutine.

Then start another conversion before exiting the handler.

Added: Or like sougata said, have a timer periodicaly start a conversion, then do the same.

HTH,

[RossWaddell]

sougata,

I'm glad it's working out for you. And yes, it is more managable. Kinda the whole idea behind it.

Squibcakes,

No, it doesn't work that way.

The AD_INT is fired on the completion of an A/D conversion. Not when the value changes.

So, in your AD_INT handler, you could test to see if the recent A/D reading differs from the previous A/D value. If it does, call a subroutine.

Then start another conversion before exiting the handler.

Added: Or like sougata said, have a timer periodicaly start a conversion, then do the same.

HTH,

I've been using DT_INTS-14 for a while with various types of interrupts but now I want to implement one for A/D. I've created the dummy interrupt handler, but my question is whether I can read the value of the conversion using PBP's ADCIN or should I grab directly from the registers. If the latter, I could use some help with that.

My ADC set up is as follows:

; PIC12F1840

DEFINE ADC_BITS      8       ; Set number of bits in result
DEFINE ADC_SAMPLEUS  5       ; Set sampling time in uS
DEFINE ADC_CLOCK     3       ; Set clock source (3=rc)

FVRCON    = 0                ' Fixed Voltage Reference is disabled
ANSELA    = %00000010        ; Analog on PORTA.1 (AN1) only
ADCON0    = %00000101        ' ADC (analog-to-digital) is enabled on AN1 (RA1) only
ADCON1.7  = 0                ; Left-justified results in 8-bits

ASM
INT_LIST  macro    ; IntSource,           Label,  Type, ResetFlag?
        INT_Handler    INT_INT, _Flash_Mode_Btn,   PBP,  yes
        INT_Handler     AD_INT, _ADC_change,       PBP,  yes
    endm
    INT_CREATE     ; Creates the interrupt processor
ENDASM


' Enable interrupts
@ INT_ENABLE   INT_INT      ; INT Interrupt
@ INT_ENABLE   AD_INT       ; A/D Interrupt

I'm working on implementing Darrel's MIBAM with a trim pot to set the brightness of an LED.