Hi all looking for a little (lot) of help with an Idea I have for an LED lamp. It consist of 6 RGB LED’s mounted in a circle in acrylic running on a atTiny85.
The LED’s will cycle though all the colors. I have made a proof of concept and it works fine on the Arduino. I know it is not wired right and that is what I need help with. Right now on the Arduino I have all the Red’s going to pin 3, all the Green’s going to pin 5 and all the Blues going to pin 6. At this time I am not using resistors.
The Forward current on all three colors is 20mA. The Forward voltage on the Red is 2.0 and on both the Green and Blue are 3.0.
I am not sure how much power I will need to drive all 6 RGB’s and the atTiny85.
I know this is asking a lot, but as I am still learning and I learn best by seeing/doing I was hoping maybe one of you pros would like to take me under your wing so to say and walk me though how to wire this. I know how to figure out what size resistors to use, that is once I know what my supply voltage is going to be. But I am thinking I am going to need transistors and maybe a Voltage Regulator. That is where I get lost.
Attached is the code I am using. I got the code off the Net.
Thank you all in advanced for any help.
-Keith
/*
RGB LED - Automatic Smooth Color Cycling
Marco Colli
April 2012
Uses the properties of the RGB Colour Cube
The RGB colour space can be viewed as a cube of colour. If we assume a cube of dimension 1, then the
coordinates of the vertices for the cubve will range from (0,0,0) to (1,1,1) (all black to all white).
The transitions between each vertex will be a smooth colour flow and we can exploit this by using the
path coordinates as the LED transition effect.
*/
// Output pins for PWM
#define R_PIN 3 // Red LED
#define G_PIN 5 // Green LED
#define B_PIN 6 // Blue LED
// Constants for readability are better than magic numbers
// Used to adjust the limits for the LED, especially if it has a lower ON threshold
#define MIN_RGB_VALUE 10 // no smaller than 0.
#define MAX_RGB_VALUE 255 // no bigger than 255.
// Slowing things down we need ...
#define TRANSITION_DELAY 70 // in milliseconds, between individual light changes
#define WAIT_DELAY 500 // in milliseconds, at the end of each traverse
//
// Total traversal time is ((MAX_RGB_VALUE - MIN_RGB_VALUE) * TRANSITION_DELAY) + WAIT_DELAY
// eg, ((255-0)*70)+500 = 18350ms = 18.35s
// Structure to contain a 3D coordinate
typedef struct
{
byte x, y, z;
} coord;
static coord v; // the current rgb coordinates (colour) being displayed
/*
Vertices of a cube
C+----------+G
/| / |
B+---------+F |
| | | | y
|D+-------|--+H ^ 7 z
|/ | / | /
A+---------+E +--->x
*/
const coord vertex[] =
{
//x y z name
{0, 0, 0}, // A or 0
{0, 1, 0}, // B or 1
{0, 1, 1}, // C or 2
{0, 0, 1}, // D or 3
{1, 0, 0}, // E or 4
{1, 1, 0}, // F or 5
{1, 1, 1}, // G or 6
{1, 0, 1} // H or 7
};
/*
A list of vertex numbers encoded 2 per byte.
Hex digits are used as vertices 0-7 fit nicely (3 bits 000-111) and have the same visual
representation as decimal, so bytes 0x12, 0x34 ... should be interpreted as vertex 1 to
v2 to v3 to v4 (ie, one continuous path B to C to D to E).
*/
const byte path[] =
{
0x01, 0x23, 0x76, 0x54, 0x03, 0x21, 0x56, 0x74, // trace the edges
0x13, 0x64, 0x16, 0x02, 0x75, 0x24, 0x35, 0x17, 0x25, 0x70, // do the diagonals
};
#define MAX_PATH_SIZE (sizeof(path)/sizeof(path[0])) // size of the array
void setup()
{
pinMode(R_PIN, OUTPUT); // sets the pins as output
pinMode(G_PIN, OUTPUT);
pinMode(B_PIN, OUTPUT);
}
void traverse(int dx, int dy, int dz)
// Move along the colour line from where we are to the next vertex of the cube.
// The transition is achieved by applying the 'delta' value to the coordinate.
// By definition all the coordinates will complete the transition at the same
// time as we only have one loop index.
{
if ((dx == 0) && (dy == 0) && (dz == 0)) // no point looping if we are staying in the same spot!
return;
for (int i = 0; i < MAX_RGB_VALUE-MIN_RGB_VALUE; i++, v.x += dx, v.y += dy, v.z += dz)
{
// set the colour in the LED
analogWrite(R_PIN, v.x);
analogWrite(G_PIN, v.y);
analogWrite(B_PIN, v.z);
delay(TRANSITION_DELAY); // wait fot the transition delay
}
delay(WAIT_DELAY); // give it an extra rest at the end of the traverse
}
void loop()
{
int v1, v2=0; // the new vertex and the previous one
// initialise the place we start from as the first vertex in the array
v.x = (vertex[v2].x ? MAX_RGB_VALUE : MIN_RGB_VALUE);
v.y = (vertex[v2].y ? MAX_RGB_VALUE : MIN_RGB_VALUE);
v.z = (vertex[v2].z ? MAX_RGB_VALUE : MIN_RGB_VALUE);
// Now just loop through the path, traversing from one point to the next
for (int i = 0; i < 2*MAX_PATH_SIZE; i++)
{
// !! loop index is double what the path index is as it is a nybble index !!
v1 = v2;
if (i&1) // odd number is the second element and ...
v2 = path[i>>1] & 0xf; // ... the bottom nybble (index /2) or ...
else // ... even number is the first element and ...
v2 = path[i>>1] >> 4; // ... the top nybble
traverse(vertex[v2].x-vertex[v1].x,
vertex[v2].y-vertex[v1].y,
vertex[v2].z-vertex[v1].z);
}
}
