Reputation: 24238
Thanks for looking!
I am building a quadcopter on each arm of which I have placed a strip of RGB addressable LEDs. I am using an Arduino to drive the lights and the Arduino code is C++, a language I don't know very well.
Here is the first StackOverflow question I posted regarding a previous problem I had with this code. It gives you more background about what exactly I am trying to do (if you are interested).
I have now properly written the array "gpsHoldArr" thanks to the answers to my first question, but I am having trouble accessing it's values.
In the code below, I call toggleLights(gpsHoldArr[x][y])
and pass in a subarray of gpsHoldArr
. The subarray should be the result of pointing to a given LED strip ([x]
) and then a given step ([y]
).
toggleLights
should then iterate the array it is passed and send the value of each LED (some number from 1-6) it is on and that LED's red, green, and blue value to the console.
Unfortunately, when I run the code below, I get this error:
cannot convert int(*)[3] to int* for argument 1 to 'void toggleLights(int*)'
Any help would be greatly appreciated.
//4 arms, 6 steps, 6 leds
int gpsHoldArr[4][6][6][3] = {
{
{{255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}}
},
{
{{255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}}
},
{
{{255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}}
},
{
{{255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {0,0,0}},
{{255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}, {255,0,0}}
}
};
toggleLights(gpsHoldArr[0][0]); //Toggles lights on strip #1, step #1
toggleLights(gpsHoldArr[1][0]); //Toggles lights on strip #2, step #1
toggleLights(gpsHoldArr[2][0]); //Toggles lights on strip #3, step #1
toggleLights(gpsHoldArr[3][0]); //Toggles lights on strip #4, step #1
void toggleLights(int lights[]){
for(int i = 0; i <= 6; ++i)
{
set_color_led(i, lights[i], lights[i], lights[i]);
}
}
void set_color_led(int led, int r, int g, int b){
Serial.println(led); //Which LED (or "pixel") is it?
Serial.println(r); //What is the red value?
Serial.println(g); //What is the green value?
Serial.println(b); //What is the blue value?
}
Upvotes: 1
Views: 398
Reputation: 480
I don't think that toggleLights()
is doing what you think it is doing. Its input is a 1-D array, but you are passing it a 2-D array of size [6][3]. When toggleLights(gpsHoldArr[0][0]);
is called, the 1-D memory array that the function sees is {255,0,0,0,0,0}
, i.e. the first six values in your array. Then, for each of these values you are calling set_color_led();
and passing the same value for multiple arguments. Unrolling the loop in toggleLights()
, this translates to
// set_color_led(i, lights[i], lights[i], lights[i]) for i = {0, ..., 6}
set_color_led(0, 255, 255, 255);
set_color_led(1, 0, 0, 0);
set_color_led(2, 0, 0, 0);
set_color_led(3, 0, 0, 0);
set_color_led(4, 0, 0, 0);
set_color_led(5, 0, 0, 0);
set_color_led(6, 0, 0, 0); // bug here as noted by molbdnilo
This is probably not what you want. I would change the definition of toggleLights()
to the following:
void toggleLights(int lights[][3]){
for(int i = 0; i < 6; ++i)
{
set_color_led(i, lights[i][0], lights[i][1], lights[i][2]);
}
}
In this case when calling toggleLights(gpsHoldArr[0][0]);
, the 2-D array that this function see is
{{255,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}, {0,0,0}}
and unrolling the loop in toggleLights()
, this translates to the following series of function calls:
// set_color_led(i, lights[i][0], lights[i][1], lights[i][2]) for i = {0, ..., 5}
set_color_led(0, 255, 0, 0);
set_color_led(1, 0, 0, 0);
set_color_led(2, 0, 0, 0);
set_color_led(3, 0, 0, 0);
set_color_led(4, 0, 0, 0);
set_color_led(5, 0, 0, 0);
Upvotes: 1
Reputation: 66459
I would probably go about it like this, removing some repetition along the way.
(Macro trickery only because of Arduino - on a desktop I would use classes instead of arrays.)
struct LED { int r, g, b; };
#define BLACK {0, 0, 0}
#define RED {255, 0, 0}
#define DEFAULT_LEDS \
{ {RED, BLACK, BLACK, BLACK, BLACK, BLACK},\
{RED, RED, BLACK, BLACK, BLACK, BLACK},\
{RED, RED, RED, BLACK, BLACK, BLACK},\
{RED, RED, RED, RED, BLACK, BLACK},\
{RED, RED, RED, RED, RED, BLACK},\
{RED, RED, RED, RED, RED, RED}}
LED gpsHoldArr[4][6][6] = {
DEFAULT_LEDS,
DEFAULT_LEDS,
DEFAULT_LEDS,
DEFAULT_LEDS
};
void set_color_led(int index, const LED& led){
Serial.println(index); //Which LED (or "pixel") is it?
Serial.println(led.r); //What is the red value?
Serial.println(led.g); //What is the green value?
Serial.println(led.b); //What is the blue value?
}
void toggleLights(LED (&leds)[6]){
for(int i = 0; i < 6; ++i) // You had a '<=' bug here.
{
set_color_led(i, leds[i]);
}
}
toggleLights(gpsHoldArr[0][0]); //Toggles lights on strip #1, step #1
Upvotes: 2
Reputation: 31972
You are passing in a 2D array when your function exists a 1D array (decayed to a pointer).
Can I suggest eliminating array dimmensions by making structs/classes, it will make stuff much clearer.
for e.g
struct Led{
int r,g,b;
};
void toggleLights(Led lights[]){
Led gpsHoldArr[4][6][6] =
set_color_led(i, lights[i].r, lights[i].g, lights[i].b);
That should be all the changes you need to make, the rest should work as-is.
You can go further and make an arm struct
and a step struct
as well.
Upvotes: 1