Fading Colors with a Shiftbrite

system · September 21, 2009, 3:23am

I have purchased some shiftbrite modules:

I am trying to get the following code to fade instead of quickly blink between the two colors... I have tried a couple diffent tactics and I've hit a brick wall. Here is a copy of the "example code" macetech provides.

#define clockpin 13 // CI
#define enablepin 10 // EI
#define latchpin 9 // LI
#define datapin 11 // DI
 
#define NumLEDs 2
 
int LEDChannels[NumLEDs][3] = {0};
int SB_CommandMode;
int SB_RedCommand;
int SB_GreenCommand;
int SB_BlueCommand;
 
void setup() {
 
   pinMode(datapin, OUTPUT);
   pinMode(latchpin, OUTPUT);
   pinMode(enablepin, OUTPUT);
   pinMode(clockpin, OUTPUT);
   SPCR = (1<<SPE)|(1<<MSTR)|(0<<SPR1)|(0<<SPR0);
   digitalWrite(latchpin, LOW);
   digitalWrite(enablepin, LOW);
 
 
}
 
void SB_SendPacket() {
 
    if (SB_CommandMode == B01) {
     SB_RedCommand = 120;
     SB_GreenCommand = 100;
     SB_BlueCommand = 100;
    }
 
    SPDR = SB_CommandMode << 6 | SB_BlueCommand>>4;
    while(!(SPSR & (1<<SPIF)));
    SPDR = SB_BlueCommand<<4 | SB_RedCommand>>6;
    while(!(SPSR & (1<<SPIF)));
    SPDR = SB_RedCommand << 2 | SB_GreenCommand>>8;
    while(!(SPSR & (1<<SPIF)));
    SPDR = SB_GreenCommand;
    while(!(SPSR & (1<<SPIF)));
 
}
 
void WriteLEDArray() {
 
    SB_CommandMode = B00; // Write to PWM control registers
    for (int h = 0;h<NumLEDs;h++) {
        SB_RedCommand = LEDChannels[h][0];
        SB_GreenCommand = LEDChannels[h][1];
        SB_BlueCommand = LEDChannels[h][2];
        SB_SendPacket();
    }
 
    delayMicroseconds(15);
    digitalWrite(latchpin,HIGH); // latch data into registers
    delayMicroseconds(15);
    digitalWrite(latchpin,LOW);
 
    SB_CommandMode = B01; // Write to current control registers
    for (int z = 0; z < NumLEDs; z++) SB_SendPacket();
    delayMicroseconds(15);
    digitalWrite(latchpin,HIGH); // latch data into registers
    delayMicroseconds(15);
    digitalWrite(latchpin,LOW);
 
}
 
void loop() {
 
   LEDChannels[0][0] = 1023;
   LEDChannels[0][1] = 0;
   LEDChannels[0][2] = 0;
 
   LEDChannels[1][0] = 0;
   LEDChannels[1][1] = 0;
   LEDChannels[1][2] = 1023;
 
   WriteLEDArray();
   delay(200);
 
   LEDChannels[0][0] = 0;
   LEDChannels[0][1] = 0;
   LEDChannels[0][2] = 1023;
 
   LEDChannels[1][0] = 1023;
   LEDChannels[1][1] = 0;
   LEDChannels[1][2] = 0;
 
   WriteLEDArray();
   delay(200);
 
 
}

Again any help would be greatly appreciated

macegr · September 21, 2009, 6:33am

Aaron,

I sent you an email with the following code on the 17th, maybe there is a problem with your inbound email.

You can use this function to fade between two colors in 32 steps, with a specified delay between each step:

void fadeall(int rate, int fromred, int fromgreen, int fromblue, int tored, int togreen, int toblue) {
for (int i = 0; i < 33; i++) {
 for (int j1 = 0; j1 < NumLEDs; j1++) {
      LEDChannels[j1][0] = (fromred * (32 - i) + tored * i)/32;
      LEDChannels[j1][1] = (fromgreen * (32 - i) + togreen * i)/32;
      LEDChannels[j1][2] = (fromblue * (32 - i) + toblue * i)/32;
 }
 WriteLEDArray();
 delay(rate);
 }
}

system · September 21, 2009, 3:27pm

Thanks there must be a problem, I figured you would reply. I'll double check my trash can my spam filter may have grabbed it (I thought I checked it but I have been out of town) Thanks a Bunch I can't wait to test it when I get home tonight!

system · September 25, 2009, 7:06pm

Ok the code works great... on a Duemilanove but when I move to a Pro Mini the LEDs flicker.

This is the code I am using I have even taken out the "fade" just trying to get 2 LEDs to light correctly is proving difficult with the Mini Pro....

#define clockpin 13 // CI
#define enablepin 10 // EI
#define latchpin 9 // LI
#define datapin 11 // DI

#define NumLEDs 2

int LEDChannels[NumLEDs][3] = {0};
int SB_CommandMode;
int SB_RedCommand;
int SB_GreenCommand;
int SB_BlueCommand;

void setup() {

   pinMode(datapin, OUTPUT);
   pinMode(latchpin, OUTPUT);
   pinMode(enablepin, OUTPUT);
   pinMode(clockpin, OUTPUT);
   SPCR = (1<<SPE)|(1<<MSTR)|(0<<SPR1)|(0<<SPR0);
   digitalWrite(latchpin, LOW);
   digitalWrite(enablepin, LOW);


}

void SB_SendPacket() {

    if (SB_CommandMode == B01) {
     SB_RedCommand = 120;
     SB_GreenCommand = 100;
     SB_BlueCommand = 100;
    }

    SPDR = SB_CommandMode << 6 | SB_BlueCommand>>4;
    while(!(SPSR & (1<<SPIF)));
    SPDR = SB_BlueCommand<<4 | SB_RedCommand>>6;
    while(!(SPSR & (1<<SPIF)));
    SPDR = SB_RedCommand << 2 | SB_GreenCommand>>8;
    while(!(SPSR & (1<<SPIF)));
    SPDR = SB_GreenCommand;
    while(!(SPSR & (1<<SPIF)));

}

void WriteLEDArray() {

    SB_CommandMode = B00; // Write to PWM control registers
    for (int h = 0;h<NumLEDs;h++) {
        SB_RedCommand = LEDChannels[h][0];
        SB_GreenCommand = LEDChannels[h][1];
        SB_BlueCommand = LEDChannels[h][2];
        SB_SendPacket();
    }

    delayMicroseconds(15);
    digitalWrite(latchpin,HIGH); // latch data into registers
    delayMicroseconds(15);
    digitalWrite(latchpin,LOW);

    SB_CommandMode = B01; // Write to current control registers
    for (int z = 0; z < NumLEDs; z++) SB_SendPacket();
    delayMicroseconds(15);
    digitalWrite(latchpin,HIGH); // latch data into registers
    delayMicroseconds(15);
    digitalWrite(latchpin,LOW);

}

void fadeall(int rate, int fromred, int fromgreen, int fromblue, int tored, int togreen, int toblue) {
for (int i = 0; i < 33; i++) {
 for (int j1 = 0; j1 < NumLEDs; j1++) {
      LEDChannels[j1][0] = (fromred * (32 - i) + tored * i)/32;
      LEDChannels[j1][1] = (fromgreen * (32 - i) + togreen * i)/32;
      LEDChannels[j1][2] = (fromblue * (32 - i) + toblue * i)/32;
 
 WriteLEDArray();
 delay(rate);
 }
} 

void loop() {

   LEDChannels[0][0] = 1023;
   LEDChannels[0][1] = 0;
   LEDChannels[0][2] = 0;
   
   LEDChannels[1][0] = 1023;
   LEDChannels[1][1] = 0;
   LEDChannels[1][2] = 0;
   
   WriteLEDArray();
}

I assume there is some difference in the Mini and the Duemilanov I'm missing... Any help is very much appreciated.

macegr · September 25, 2009, 9:33pm

Can't see any differences in the code or schematic that would cause a problem. Would you happen to have the 3.3V version of the Pro Mini? There would be a high chance that 3.3V levels would fall a hair too low to register as a logic high level on the ShiftBrite.

system · September 27, 2009, 1:21pm

Sorry for the delay in reply I was out cold yesterday. I have the 5v version Its really odd why this is happening... Its really not a HUGE deal I have 2 Duemilanove's I can use its just a larger footprint than I wanted for my lamps but again its not a real issue there... I may continue to experiment with the mini pro's I have but I'll most likley just use them in a different project

At least its not something simple I'm missing thats my main concern.

macegr · September 28, 2009, 2:30am

As far as wiring is concerned, you may want to pay special attention to grounding. And you should be using a separate supply to power the ShiftBrites; you're not trying to power them from the Pro Mini regulated 5V right?

system · September 28, 2009, 3:03pm

No I'm not powering them from the Arduino. I am running them from a power supply purchased from your shop I think I received 3.3v Arduinos I'm waiting on a response from SFE to determine if there is a way to verify if they are in fact 3.3 or 5v.

The ones I received with my order were not labeled on the back

BTW Thanks a ton for your help already, anyone thats reading mace has been great! I highly recommend them for RGB LEDs!!!

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Fading Colors with a Shiftbrite

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