Newbie help. RGB Led on a PIC10F202

[Jerson]

Hi Brian

Take a look at this code. ButtonCount starts with 0 and then loops between 1 and 3 depending on your button presses. You may want it to roll over to 0 and have an all off program too. EDIT : My post assumes you are using a high input as indication of switch being pressed.

Red var GPIO.0 
Green var GPIO.1 
Blue var GPIO.2 
SwitchPin var GPIO.3  
ButtonCount VAR BYTE 

    ButtonCount = 0  ;Make sure LEDs are off 

    HIGH Red  
    HIGH Green 
    HIGH Blue  

MAIN: 
SWITCHLOOP:
    if SwitchPin = 1 then
      ButtonCount = ButtonCount+1
      if ButtonCount > 3 then ButtonCount = 1
      while SwitchPin = 1: wend     ' wait here while the switch remains pressed
    endif

    If ButtonCount = 1 THEN GOSUB RedProgram 
    If ButtonCount = 2 THEN GOSUB GreenProgram 
    If ButtonCount = 3 THEN GOSUB BlueProgram 
GOTO SWITCHLOOP 

END  

RedProgram: 
    PWM Red,127,100 
RETURN  

GreenProgram: 
    PWM Green,127,100 
RETURN  

BlueProgram: 
    PWM Blue,127,100 
RETURN

END

[brianmorris]

I wish i could reply back and say that works.. But it doesnt. Its randomly cycling through each color in order (i.e.; Red, Green, Blue, etc.) without me pressing anything. Also, Im thinking i screwed up in the code i provided where the color should always stay lit UNTIL the switch is pressed, so the program always needs to be waiting for a switch press, then it changes color.

[Jerson]

I suspect the switch is connected between the pin and ground effectively giving you a logic low for a switch press. That is why the colors are cycling.
If this is truly the case, then you can do well to change these lines in switchloop

    if SwitchPin = 0 then       ButtonCount = ButtonCount+1       if ButtonCount > 3 then ButtonCount = 1       while SwitchPin = 0: wend     ' wait here while the switch remains pressed     endif

[cncmachineguy]

Good morning Brian, well morning for me anyway. We need to know a bit about your circuit. How is the switch actually connect to the pic? Do you have a pull up/down resistor?

[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.

[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.