Hello All, My first post. I hope someone can help me please or at least point me in the right direction if possible. Im trying to create a constant current high power 3 channel RGB LED lamp. I can run my drivers via the PWM pins with a potentiometer for each channel on the analogue pins with a separate 12v supply so all good there.
Being a complete novice with Arduino code Im looking for help please. I would like to add a forth dimmer to act as a master dimmer over the other 3 LED channels once the colour is set via the other 3 dimmers. Im sure its possible but I have no idea how to do it and how to modify the code below.
You don't need any extra hardware on the 12V side for the "master channel", that can all be done in the sketch.
How do you intend to control the colour and brightness? Were you thinking 3 pots for r, g & b plus a fourth for the master brightness control? You could have one pot for colour selection and one for brightness. The sketch could then translate the two pot values into r, g & b pwm values.
If you want it, a third pot could control the colour "saturation", ie. how strong or pale/pastel the colour is.
Hi Paul, thanks for your reply. I was intending to use a pot for each of the RGB channels and a 4th for the master dimmer. Also then as an option for a BI-colour lamp I could then adapt the code too maybe just 2 LED channels, one for warm white LED and one for cool white LED with a third as a master dimmer.
Im at a point where Ive got my 2 external 350ma constant 12v drivers dimmerable using the PWM pins and pots on the Uno.
Any ideas on how I could do any of that in the below sketch please? Im on a steep learning curve here, my pea brain hurts!
// Init the Pins used for PWM
const int redPin = 9;
const int greenPin = 10;
const int bluePin = 11;
// Init the Pins used for 10K pots
const int redPotPin = 0;
const int greenPotPin = 1;
const int bluePotPin = 2;
// Init our Vars
int currentColorValueRed;
int currentColorValueGreen;
int currentColorValueBlue;
void setup()
{
pinMode(redPin, OUTPUT);
pinMode(greenPin, OUTPUT);
pinMode(bluePin, OUTPUT);
}
void loop()
{
// Read the voltage on each analog pin then scale down to 0-255 and inverting the value for common anode
currentColorValueRed = (255 - map( analogRead(redPotPin), 0, 1024, 0, 255 ) );
currentColorValueBlue = (255 - map( analogRead(bluePotPin), 0, 1024, 0, 255 ) );
currentColorValueGreen = (255 - map( analogRead(greenPotPin), 0, 1024, 0, 255 ) );
// Write the color to each pin using PWM and the value gathered above
analogWrite(redPin, currentColorValueRed);
analogWrite(bluePin, currentColorValueBlue);
analogWrite(greenPin, currentColorValueGreen);
}
Here is some code for hsl to rgb conversion that might work ok.
void HSL_to_RGB(int hue, int sat, int lum, int* r, int* g, int* b)
{
int v;
v = (lum < 128) ? (lum * (256 + sat)) >> 8 :
(((lum + sat) << 8) - lum * sat) >> 8;
if (v <= 0) {
*r = *g = *b = 0;
} else {
int m;
int sextant;
int fract, vsf, mid1, mid2;
m = lum + lum - v;
hue *= 6;
sextant = hue >> 8;
fract = hue - (sextant << 8);
vsf = v * fract * (v - m) / v >> 8;
mid1 = m + vsf;
mid2 = v - vsf;
switch (sextant) {
case 0: *r = v; *g = mid1; *b = m; break;
case 1: *r = mid2; *g = v; *b = m; break;
case 2: *r = m; *g = v; *b = mid1; break;
case 3: *r = m; *g = mid2; *b = v; break;
case 4: *r = mid1; *g = m; *b = v; break;
case 5: *r = v; *g = m; *b = mid2; break;
}
}
}
I'll help you adapt your code to use it later if you like.
Sorry Paul, I didn't notice your offer of help to adapt the code, mental note "must scroll down page!" That would be amazing if you could help me out. Greatly appreciated.
Right then. Give this a go. I have not been able to test it, but it compiles OK.
// Init the Pins used for PWM
const int redPin = 9;
const int greenPin = 10;
const int bluePin = 11;
// Init the Pins used for 10K pots
const int huePotPin = A0;
const int satPotPin = A1;
const int briPotPin = A2;
// Init our Vars
int currentColorValueRed;
int currentColorValueGreen;
int currentColorValueBlue;
int currentColorValueHue;
int currentColorValueSat;
int currentColorValueBri;
void HSL_to_RGB(int hue, int sat, int lum, int* r, int* g, int* b)
{
int v;
v = (lum < 128) ? (lum * (256 + sat)) >> 8 :
(((lum + sat) << 8) - lum * sat) >> 8;
if (v <= 0) {
*r = *g = *b = 0;
} else {
int m;
int sextant;
int fract, vsf, mid1, mid2;
m = lum + lum - v;
hue *= 6;
sextant = hue >> 8;
fract = hue - (sextant << 8);
vsf = v * fract * (v - m) / v >> 8;
mid1 = m + vsf;
mid2 = v - vsf;
switch (sextant) {
case 0: *r = v; *g = mid1; *b = m; break;
case 1: *r = mid2; *g = v; *b = m; break;
case 2: *r = m; *g = v; *b = mid1; break;
case 3: *r = m; *g = mid2; *b = v; break;
case 4: *r = mid1; *g = m; *b = v; break;
case 5: *r = v; *g = m; *b = mid2; break;
}
}
}
void setup()
{
pinMode(redPin, OUTPUT);
pinMode(greenPin, OUTPUT);
pinMode(bluePin, OUTPUT);
}
void loop()
{
// Read the voltage on each analog pin then scale down to 0-255
currentColorValueHue = map( analogRead(huePotPin), 0, 1024, 0, 255 );
currentColorValueSat = map( analogRead(satPotPin), 0, 1024, 0, 255 );
currentColorValueBri = map( analogRead(briPotPin), 0, 1024, 0, 255 );
HSL_to_RGB(currentColorValueHue, currentColorValueSat, currentColorValueBri,
¤tColorValueRed, ¤tColorValueBlue, ¤tColorValueGreen);
// Write the color to each pin using PWM and the value gathered above, inverting the value for common anode
analogWrite(redPin, 255 - currentColorValueRed);
analogWrite(bluePin, 255 - currentColorValueBlue);
analogWrite(greenPin, 255 - currentColorValueGreen);
}
If it doesn't work, please don't be a newbie. Don't just say "it doesn't work". Tell us what it does do and what you wanted it to do.
Thanks so much Paul for your effort. I have just verified and up loaded your sketch. It doesn't work. Just to be clear I have 10k pots on each Analogue channels A0,A1,A2 and I have A single 5mm blue LED on PWM channel 11, a single 5mm Green Led on 10 and a single 5mm Red led on 9.
So in an ideal world I would like to be able to dim each of these 5mm leds separately with its own POT then once the correct colour temp is achieved use a forth Pot to dim all three to the desired level of brightness.
The Leds Im using don't need to be coloured, I may just use three different whites e.g warm white 2700k, 3200k and 5500k instead of the RGB colours.
At the moment all three leds are on and the three pots don't do anything when twisted using your sketch.
Doing it in the HSV color space is indeed nice. But if you want a read master effect then here you go
// Init the Pins used for PWM
const byte RedPin = 9; //byte is already big enough ;)
const byte GreenPin = 10;
const byte BluePin = 11;
// Init the Pins used for 10K pots
const byte RedPotPin = A0; //Use A0, A1 etc to make it clear it's the analog
const byte GreenPotPin = A1;
const byte BluePotPin = A2;
const byte MasterPotPin = A3;
/* No need to be global
// Init our Vars
int currentColorValueRed;
int currentColorValueGreen;
int currentColorValueBlue;
*/
void setup()
{
pinMode(RedPin, OUTPUT);
pinMode(GreenPin, OUTPUT);
pinMode(BluePin, OUTPUT);
}
void loop()
{
// Read the voltage on each analog pin then scale down to 0-255 and inverting the value for common anode
int value = 0;
int masterValue = analogRead(MasterPotPin) >> 2; //Make it 8-bit
//Red
value = analogRead(RedPotPin) >> 2; //make it 8-bit
value = (value * masterValue + 127) / 255; //scale it to master
analogWrite(RedPin, 255 - value); //invert and write
//Green
value = analogRead(GreenPotPin) >> 2;
value = (value * masterValue + 127) / 255;
analogWrite(GreenPin, 255 - value);
//Blue
value = analogRead(BluePotPin) >> 2;
value = (value * masterValue + 127) / 255;
analogWrite(BluePin, 255 - value);
}
Hi Septillion, thanks for all your effort in trying to solve my problem. Sorry for my late reply, just got in from work. Ive just uploaded your code. There seems to be a few bugs. Only PWM pin 10 LED is working. LEDs on PWM 9 & 11 aren't illuminated. Also the A0 Pot dims the pin 10 LED and A1 Pot also dims the pin 10 LED. Nothing happening with pots A2 or A3.
Hello again Paul, thanks again for your efforts. I have just uploaded your last sketch, there seems to be progress however there seems to be a few bugs in it still.
I will try and explain whats going on if I can.
When POT A2 is on max brightness all LEDs are on full the POTs A0 & A2 don't do anything.
When POT A2 is fully dimmed all LEDs are on a low glow and POT A1 works but only with PINS 11 & 10 but pin 9 stays on a low glow. Then if POT A2 is left at the fully dimmed position and A1 on max brightness then AO pot when twisted flashes all three LEDs alternately like a disco, its kinda cool but that feature isn't really required! :o
If you can figure this out you are a better man than me.
That would be amazing if you could help me out. Greatly appreciated.
Little f* up of me... Fixed the code (A)