JoelMurphy
- 5th December 2008, 16:40
hi-ho,
had this posted on the PicBasic side. it's lonely there.
i'd like to get the PIC to control a TLC5940 PWM controller for LEDs and whatnot. i have a grip on how the chip works, and how to format the data to its registers, but the 5940 requires a clock signal to time the PWM. [4096 cycles, a little handshake, 4096 more cycles...] i'm thinking 'hey, there's that TMR1 right there, why not, you know...' so i'm just ramping up on getting the CCP and TMR1 to talk to eachother. part of my solution for timing the PWM is to use the INTRC (clockout) configuration. i'm running a 16F88 and have gotten some good results with my test code, and i want to visualize the clockout on RA6. so, i went ahead and put an LED on it. it gives a little blink when the program starts up, but then nothing. what's going on? am i asking too much of the little OSC2? i even put my multimeter on it, thinking that i would at least see some +V... nuthin.
simple code below. sorry darryl, i'm not using your amazing thing.
as a side note, the software toggle of B.4 goes on and off like you read about. but the mulitplexed B.3 just sits there sorta 'on' even though i'm setting it low in the isr. i woulda thought that it would also give me some kind of pulsing output.
16F88, INTRC clockout, disable BOR due to 3V3
OSCCON = %0110110 '4MHz INTERNAL OSCILLATOR
ANSEL = %00000000 'MAKE PortA PINS ALL DIGITAL
TRISB = %00000000
LED VAR PortB.4
LED1 VAR PortB.3
T1CON = %00100001 'ENABLE TIMRE ONE, PRESCALE 1:1, USE INTERNAL CLK
INTCON = %11000000 'ENABLE GLOBAL INT, ENABLE PERIPHERAL INT,
PIE1 = %00000100 'ENABLE CCP1 INT
CCP1CON = %00001000 'COMPARE MODE, SET OUTPUT ON MATCH
CCPR1L = %00000000 'SET CCP REGISTER TO 4069
CCPR1H = %00010000
on interrupt goto ISR
Main:
PAUSE 1
GOTO Main
DISABLE
ISR:
TOGGLE LED
LOW led1
PIR1.2 = 0
TMR1H = 0
TMR1L = 0
RESUME
ENABLE
had this posted on the PicBasic side. it's lonely there.
i'd like to get the PIC to control a TLC5940 PWM controller for LEDs and whatnot. i have a grip on how the chip works, and how to format the data to its registers, but the 5940 requires a clock signal to time the PWM. [4096 cycles, a little handshake, 4096 more cycles...] i'm thinking 'hey, there's that TMR1 right there, why not, you know...' so i'm just ramping up on getting the CCP and TMR1 to talk to eachother. part of my solution for timing the PWM is to use the INTRC (clockout) configuration. i'm running a 16F88 and have gotten some good results with my test code, and i want to visualize the clockout on RA6. so, i went ahead and put an LED on it. it gives a little blink when the program starts up, but then nothing. what's going on? am i asking too much of the little OSC2? i even put my multimeter on it, thinking that i would at least see some +V... nuthin.
simple code below. sorry darryl, i'm not using your amazing thing.
as a side note, the software toggle of B.4 goes on and off like you read about. but the mulitplexed B.3 just sits there sorta 'on' even though i'm setting it low in the isr. i woulda thought that it would also give me some kind of pulsing output.
16F88, INTRC clockout, disable BOR due to 3V3
OSCCON = %0110110 '4MHz INTERNAL OSCILLATOR
ANSEL = %00000000 'MAKE PortA PINS ALL DIGITAL
TRISB = %00000000
LED VAR PortB.4
LED1 VAR PortB.3
T1CON = %00100001 'ENABLE TIMRE ONE, PRESCALE 1:1, USE INTERNAL CLK
INTCON = %11000000 'ENABLE GLOBAL INT, ENABLE PERIPHERAL INT,
PIE1 = %00000100 'ENABLE CCP1 INT
CCP1CON = %00001000 'COMPARE MODE, SET OUTPUT ON MATCH
CCPR1L = %00000000 'SET CCP REGISTER TO 4069
CCPR1H = %00010000
on interrupt goto ISR
Main:
PAUSE 1
GOTO Main
DISABLE
ISR:
TOGGLE LED
LOW led1
PIR1.2 = 0
TMR1H = 0
TMR1L = 0
RESUME
ENABLE