APA102 on STM32F070F6

apa102.cpp

/*
* Simplified code for running APA-102 on STM32
* (or most any other platform by replacing the
* sendRaw-method with platform SPI calls)
*/

#define NUMBER_OF_LEDS 46	// Define number of LEDs in the chain
#define COLORS_PER_LED 3	// Define number of colors we store

const int bufferLength = NUMBER_OF_LEDS*3;
uint8_t ledBuffer[NUMBER_OF_LEDS*COLORS_PER_LED];

void sendRaw(uint8_t data) {
	HAL_SPI_Transmit(&hspi1, &data, 1, 1000);
}

void update() {
	// StartFrame (0x00000000)
	sendRaw(0x00);
	sendRaw(0x00);
	sendRaw(0x00);
	sendRaw(0x00);

	// Loop over all the LEDs
	for (int led = 0; led < NUMBER_OF_LEDS; led++) {
		int ledNum = led*3;
		// For POV, we always want full intensity (31 brightness), so we send the first 8 bits as 0xFF
		// the 3 INIT bits should always be 0xE0 (11100000) + the brightness bits should also all be ones 0x1F (00011111) = 0xFF
		sendRaw((uint8_t) (0xFF) );
		sendRaw((uint8_t) (ledBuffer[ledNum]));   // Send BLUE
		sendRaw((uint8_t) (ledBuffer[ledNum+1])); // Send GREEN
		sendRaw((uint8_t) (ledBuffer[ledNum+2])); // Send RED
	}

	// EndFrame (0xffffffff)
	sendRaw(0xff);
	sendRaw(0xff);
	sendRaw(0xff);
	sendRaw(0xff);
	// Note that if you have a lot of LEDs, check this post at Tim's blog:
	// https://cpldcpu.wordpress.com/2014/11/30/understanding-the-apa102-superled/
}

uint8_t TestPosition(const uint8_t led) {
	uint8_t returnValue = OUT_OF_RANGE;
	if (led < bufferLength) {
		returnValue = RANGE_OK;
	}
	return returnValue;
}

// Smooth rainbow color code from Adafruit. Thanks for always helping the community!
void setColor( uint8_t led, uint8_t red,  uint8_t green, uint8_t blue ) {
	int ledNum = led*3;
	if (TestPosition(ledNum) == RANGE_OK) {
		ledBuffer[ledNum] = blue;
		ledBuffer[ledNum+1] = green;
		ledBuffer[ledNum+2] = red;
	}
}

void setRGB( uint8_t led, uint32_t rgb)
{
	setColor(led, (uint8_t)(rgb), (uint8_t)(rgb >> 8), (uint8_t)(rgb >> 16 ));
}

uint32_t Color(uint8_t r, uint8_t g, uint8_t b) {
  return ((uint32_t)b << 16) | ((uint32_t)g <<  8) | r;
}

uint32_t Wheel(uint8_t WheelPos) {
  uint32_t result = 0;
  WheelPos = 255 - WheelPos;
  if(WheelPos < 85) {
	  result =  Color(255 - WheelPos * 3, 0, WheelPos * 3);
  } else if(WheelPos < 170) {
    WheelPos -= 85;
    result =  Color(0, WheelPos * 3, 255 - WheelPos * 3);
  } else {
	  WheelPos -= 170;
	  result = Color(WheelPos * 3, 255 - WheelPos * 3, 0);
  }
  return result;
}

void rainbow(uint8_t wait) {
	uint16_t i, j;
	for (j = 0; j < 256; j++) {
		for (i = 0; i < NUMBER_OF_LEDS; i++) {
			setRGB(i, Wheel((i + j) & 255) );
		}
		update();
	}
}