Newbie help. RGB Led on a PIC10F202

[mister_e]

Yup, or there's no pull-up/down resistor. whatever

        '-------------------------------------------------------------------------------------------
        '
        '       The following have been tested, no problem at all
        '       
        '       Hardware description
        '           1) LEDs connected betwee PIC I/O and GND via resistor
        '           2) Push button between PIC and GND... nothing else.
        ' 
        '-------------------------------------------------------------------------------------------  
         
@       __config _WDT_OFF & _MCLRE_OFF & _CP_OFF
                ' Disable watch dog timer
                ' Disable MLCR, GP3 as I/O
                ' Disable Code Protection 
                              
        Red         var GPIO.0
        Green       var GPIO.1
        Blue        var GPIO.2
        SwitchPin   var GPIO.3  ' Active low
       
        OPTION_REG = %00000000
                   ' -0-------- _GPWU -- Disable Wake-Up on pin change
                   ' --0------- _GFPPU - Enable Weak Pull-Ups 
                   ' ---0------ T0CS --- Timer0 Clock Source Internal (O T0CKI pin, 0 Internal)
                   ' ----xxxxx- Timer0 related stuff... don't care
        
        TRISIO = 0          ' Clear all I/Os
        GPIO = %00001000    ' GP3: Input, other pin: Output 
               
        ButtonCount VAR BYTE

MAIN:
        IF !SwitchPin THEN                              ' Switch down?
                                                        ' - YES
                If ButtonCount = 3 THEN ButtonCount = 0 ' - Currently on GP3 (MCLR)?  If so, pass go, claim 200$ 
                pwm ButtonCount,127,100                 ' - Light Show
                WHILE !SwitchPin : wend                 ' - Spin 'till button is released
                pAUSE 50                                ' - arbitrary debouince delay
                ButtonCount = ButtonCount + 1           ' - Point to next LED
                endif                                   ' 
        GOTO MAIN

[brianmorris]

Simple circuit. VDD hooked up to 3.7v, GPIO.0 to Red Lead, GPIO.1 to Green Lead, GPIO.2 to Blue Lead, GPIO.3 to Switch and ground when pressed, Vss hooked to Ground. And of course resistors coming from each of the I/O pins to the LED cathodes while the anode goes to 3.7v.

Steve, When i run your code i get all three leds on, making white, press button i get Bright Blue, press button again i get more of a regular blue, again i get a dim green with both green and red leds lit.

But at least the switch is working.

[cncmachineguy]

So If the switch is not pressed, the input pin is floating, unless there are weak pull-ups in play here. If not, try adding a pull-up to the input. This way the input is either high or low, but never allowed to float.

[brianmorris]

I connected a 10k resistor from VCC to GPIO.3 and then the button is still connected to GPIO.3 and GND. Push the button, the color changes, but still the same as above.

[sayzer]

Your LEDs are conected to Vdd instead of GND.
And GPIO is set to 0, so initially all pins are low at the beginning and thus LEDs are on.
When a PWM cycle is done, the pin stays low again and the LED is still on.

I am guessing Steve forgat to add these in his last posted code above.


Before "pwm ButtonCount,127,100", insert these:

HIGH RED
HIGH GREEN
HIGH BLUE

So the new code will be as below:

MAIN:
 
        IF !SwitchPin THEN                              ' Switch down?
 
                                                        ' - YES
 
                If ButtonCount = 3 THEN ButtonCount = 0 ' - Currently on GP3 (MCLR)?  If so, pass go, claim 200$ 
 
                HIGH RED
 
                HIGH GREEN
 
                HIGH BLUE       
                pwm ButtonCount,127,100                 ' - Light Show
 
                WHILE !SwitchPin : wend                 ' - Spin 'till button is released
 
                pAUSE 50                                ' - arbitrary debouince delay
 
                ButtonCount = ButtonCount + 1           ' - Point to next LED
 
                endif                                   ' 
        GOTO MAIN

[brianmorris]

I have one RGB LED with a common anode thats hooked up to VDD. The individual pins are connected to the I/O ports on the chip. I entered in the code above but all colors are still on. The even funnier part is i even commented out those lines including the PWM line and all three are still on. I commented out just the PWM line, same thing. I even erased the chip, verified erase and reprogrammed.

[sayzer]

cmcon0 = 0

[mister_e]

Steve, When i run your code i get all three leds on, making white, press button i get Bright Blue, press button again i get more of a regular blue, again i get a dim green with both green and red leds lit.

But at least the switch is working.

I guess i've been lucky then, modifs in RED

        TRISIO = 0          ' Clear all I/Os
        GPIO = %00001000    ' GP3: Input, other pin: Output 
               
        ButtonCount VAR BYTE
        CLEAR
MAIN:
        IF !SwitchPin THEN                              ' Switch down?
                                                        ' - YES
                If ButtonCount = 3 THEN ButtonCount = 0 ' - Currently on GP3 (MCLR)?  If so, pass go, claim 200$ 
                PWM ButtonCount,127,100                 ' - Light Show
                LOW ButtonCount
                WHILE !SwitchPin : WEND                 ' - Spin 'till button is released
                PAUSE 50                                ' - arbitrary debouince delay
                ButtonCount = ButtonCount + 1           ' - Point to next LED
                endif                                   ' 
        GOTO MAIN

[brianmorris]

Bruce, your code is working perfectly. I can cycle through every color, the only thing I am having trouble with is maybe the switch is a tad too sensitive. I am thinking maybe using TMR0 where if i hold down the switch for 1-2 seconds, it will then change colors.

[Bruce]

Probably just a really bad case of switch bounce. Try adjusting the delay something like this;

     WHILE !SwitchPin
        PAUSE 50  ' adjust this until it starts acting right. 
     WEND

That might do it. If not place this same code at the bottom just before it returns to Main.

You could also increment a variable in the WHILE loop. When it reaches a certain value it will indicate approx how long the switch was held down.

[sayzer]

In Steve's code, PWM command should be in the main loop.

[mister_e]

..........huh?