Visualize Clockout

[Bruce]

Trying to drive an LED with OSC2 out is probably not going to work, as it's not designed to
drive LEDs. It's a low-current clock output. You might get by with applying OSC2 out to the
base of a transistor, but I've never tried it.

And your multi-meter may not be fast enough to keep up with a 2MHz pulse out on OSC2.

An LED turned ON/OFF at 2MHz will most likely appear to be dimly lit all the time. 2MHz is
pretty quick.

Your comment for TIMER1 prescaler is wrong. You actually have the prescaler set to 1:4,
and your comment on the value of CCPR1 is wrong too. It should be 4096 VS 4069.

If you want to see the LEDs blink, you're going to need a lot more time between interrupts.

Try something like this;

@ DEVICE INTRC_OSC_CLKOUT, LVP_OFF, WDT_OFF, MCLR_OFF, BOD_OFF, CCPMX_ON, PWRT_ON

OSCCON = %00010000 ' 125kHz INTERNAL OSCILLATOR
ANSEL = %00000000  ' MAKE PortA PINS ALL DIGITAL
PORTB = 0          ' ALL CLEAR AT POR
TRISB = %00000000

LED VAR PortB.4
LED1 VAR PortB.3

T1CON = %00110001   ' ENABLE TIMER1, PRESCALE 1:8, INTERNAL CLK
PIE1 = %00000100    ' ENABLE CCP1 INT
CCP1CON = %00001011 ' COMPARE MODE, AUTO RESET TIMER1
CCPR1L = %00000000  ' SET CCP REGISTER TO 4096 
CCPR1H = %00010000  ' 4096*8*32uS = 1.048 seconds toggle rate
INTCON = %11000000  ' ENABLE GLOBAL INT, ENABLE PERIPHERAL INT.

on interrupt goto ISP

Main:
    @ nop
    GOTO Main

DISABLE
ISP:
    TOGGLE LED
    TOGGLE LED1
    PIR1.2 = 0
    RESUME
    ENABLE

[JoelMurphy]

bruce, thanks for the reply,

i may try to put an NPN on OSC2 to see what's up. but i'm more interested in controlling the PWM driver.

i have the PIC connected to the TLC PWM driver, and it's not working. although it looks like there may be a faint glimmer of life on startup. the thing that gets the PWM going is the GSCLK which i'm attempting to drive with my clockout.
the DS for the TLC says that minimum pulse time for GSCLK is 16ns. i'm way in range there...

will try to slow everything down to make sure my timing is matching what the driver needs.
also thinking about using TMR0 interrupt at 1:16 and toggling my output in the ISR.

by the way, the pins on the TLC i'm concerned about are
GSCLK greyscale clock which the chip uses to time the PWM
BLANK which is toggled at the end/beginning of each 4096 clock period

i hope the CCP1 can work, cause it's so cool.
anybody else use this type of LED controller?