/*----------------------------------------------------------------------- WS2812Ctrl.c Control of LED Strip with WS2812B driver ----------------------------------------------------------------------- Last committed: $Revision: 05 $ Last changed by: $Author: Thomas.Stief@web.de$ Last changed date: $Date: 04.05.2015 $ ID: $Id: WS2812Ctrl $ ----------------------------------------------------------------------- Resources ----------------------------------------------------------------------- * µC: STM32F103C8 - GPIO: A0 - Timer: TIM2 - DMA: DMA1 Channel 2 - IRQ: DMA1_Channel2_IRQHandler ----------------------------------------------------------------------- Revision History ----------------------------------------------------------------------- 01 - Created 02 - Interface adjusted 03 - Calculation of psychophysic perception included - additional coding value in COLOR struct included -> different coding possible for individual LED 04 - Remove relics of Standard peripheral library - Change extension to CPP - use within C++ projects 05 - Remove SPL completely, declare ISR as extern "C" ----------------------------------------------------------------------- ToDo ----------------------------------------------------------------------- - */ #include "stm32f10x.h" #include "WS2812Ctrl\WS2812Ctrl.h" #include "HSV2RGB\hsv2rgb.h" // Define internal Functions void fillDMABuffer(uint8_t nPos); // Define internal variables // PWM table const uint8_t u8PWMValue[64] = { 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 4, 5, 5, 6, 7, 8, 9, 11, 12, 13, 15, 17, 19, 20, 23, 25, 27, 30, 32, 35, 38, 41, 45, 48, 52, 56, 60, 64, 68, 73, 78, 83, 88, 93, 99, 105, 111, 117, 124, 131, 138, 145, 153, 161, 169, 177, 186, 195, 204, 214, 224, 234, 244, 255 }; // DMA Buffer uint8_t DMABuffer[48]; // Data Pointer COLOR *pLEDData; // Number of LEDs stored in pData uint16_t nLED=0; // Counter LEDs transfered volatile uint16_t iLED=0; void initWS2812(void) { // Init GPIO // -------------------------------------------------------------- RCC->APB2ENR|= RCC_APB2ENR_IOPAEN; // GPIOA: Clock enable GPIOA->CRL &= ~GPIO_CRL_MODE0 & ~GPIO_CRL_CNF0; // initialize GPIOA->CRL Pin0 GPIOA->CRL |= GPIO_CRL_CNF0_1 | // GPIOA.0 -> Alternative function, Push-Pull GPIO_CRL_MODE0_1; // GPIOA.0 -> Mode Output, 2MHz // Init DMA // -------------------------------------------------------------- RCC->AHBENR |= RCC_AHBENR_DMA1EN; // DMA1: Clock enable DMA1_Channel2->CCR &=~DMA_CCR2_EN; // disable DMA1 Channel 2 DMA1_Channel2->CPAR = (uint32_t)&(TIM2->CCR1); // Set Base-Address Peripheral DMA1_Channel2->CMAR = (uint32_t)DMABuffer; // Set Base-Address Memory DMA1_Channel2->CNDTR = 48; // Buffer len DMA1_Channel2->CCR = DMA_CCR2_TCIE | // Transfer Complete IRQ enable DMA_CCR2_HTIE | // Half Transfer IRQ enable DMA_CCR2_DIR | // Memory -> Peripheral DMA_CCR2_CIRC | // Circular Mode enable /* DMA_CCR2_PINC | */ // Memory increment disable DMA_CCR2_MINC | // Memory increment enable DMA_CCR2_PSIZE_0 | // PSIZE[1:0] = 01 -> Peripheral = 16bit /* DMA_CCR2_MSIZE_0 | */ // MSIZE[1:0] = 00 -> Memory = 8bit DMA_CCR2_PL_1 ; // PL[1:0] = 10 -> Priority = high /* DMA_CCR2_MEM2MEM */ // MEM2MEM disable // Init TIM2 // -------------------------------------------------------------- RCC->APB1ENR |= RCC_APB1ENR_TIM2EN; // Basic Init TIM2->PSC = 0; // no prescale -> clock TIM2 = 72MHz TIM2->ARR = 90; // Counting 0 ... 89 @ 72MHz = 800kHz (DT = 1,25µs) TIM2->CCR1 = 0; // Capture Compare = 0 -> register will be modified by DMA-Transfer TIM2->CR1 &=~TIM_CR1_DIR & // Upward counting ~TIM_CR1_CMS; // Edge aligned mode TIM2->CCMR1 = TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1M_1; // PWM Mode 1: active @ CNT < CCR1 / not active @ CNT > CCR1 / PWM Channel 2 disabled TIM2->CCMR2 = 0; // PWM Channel 3 and 4 disabled TIM2->CCER |= TIM_CCER_CC1E; // Channel configured as output /* &~TIM_CCER_CC1P */ // Channel active high // Activate DMA Transfer TIM2->DIER |= TIM_DIER_UDE; // DMA Transfer Update cmd. enable // Init Core // -------------------------------------------------------------- NVIC_SetPriority(DMA1_Channel2_IRQn,0); // Set Priority of DMA-IRQ to high DBGMCU->CR |= DBGMCU_CR_DBG_TIM2_STOP; // Timer stop @ break } uint8_t doTransferWS2812(COLOR *_pLEDData, uint16_t _nLED) { // initialize internal Data and store parameters // -------------------------------------------------------------- if(iLED > 0) // if iLED > 0 -> transfer in progress return 0; // return with error pLEDData=_pLEDData; // store data pointer nLED=_nLED; // store count LED-data to be transfered // fill DMABuffer // -------------------------------------------------------------- fillDMABuffer(0); // fill lower part of DMA-Buffer with data of first LED fillDMABuffer(24); // fill higher part of DMA-Buffer with data of second LED // enable transfer to WS2812-LEDs // -------------------------------------------------------------- NVIC_EnableIRQ(DMA1_Channel2_IRQn); // enable DMA-IRQ DMA1_Channel2->CNDTR = 48; // init DMA: set pending transfers to 48 DMA1_Channel2->CCR|= DMA_CCR1_EN; // enable DMA1 Channel 2 TIM2->CNT = 0; // Set timer to 0 -> timer start at the TIM2->CR1 |= TIM_CR1_CEN; // enable timer return 1; // return without error } extern "C" void DMA1_Channel2_IRQHandler(void) { if((DMA1->ISR & DMA_ISR_HTIF2) != 0) // check if half transfer flag is set { DMA1->IFCR = DMA_IFCR_CHTIF2; // clear half transfer flag fillDMABuffer(0); // fill lower part of DMA buffer with next LED data } // Transfer complete -> refill upper DMABuffer if((DMA1->ISR & DMA_ISR_TCIF2) != 0 ) // check if transfer complete flag is set { DMA1->IFCR = DMA_IFCR_CTCIF2; // clear transfer complete flag fillDMABuffer(24); // fill upper part of DMA buffer with next LED data } // if iLED < nLED -> fillDMABuffer will fill the next LED data into the Buffer // if iLED >= nLED -> fill DMABuffer will fill Zeros into the Buffer results in pin @ low -> LED-Bus reset if(iLED > nLED+2) // after 2 Transfers with Zeros => deactivate Timer, DMA and IRQs { TIM2->CR1 &=~TIM_CR1_CEN; // disable Timer 2 DMA1_Channel2->CCR &=~DMA_CCR1_EN; // disable DMA1 Channel 2 NVIC_DisableIRQ(DMA1_Channel2_IRQn); // disable DMA-IRQ iLED = 0; // counter iLED = 0 -> flag for "transfer complete" } } void fillDMABuffer(uint8_t nPos) { uint8_t i,r,g,b; if(iLED fill DMABuffer with next LED data { switch(pLEDData[iLED].Coding) { case COLOR_CODING_HSV: // LED Data stored as HSV-Value in pLEDData translateHSVtoRGB(pLEDData[iLED].h,pLEDData[iLED].s,pLEDData[iLED].v,&r,&g,&b); // translate next LED data (HSV-Value) into RGB value and store this in r,g,b // Adjust RGB-values accordingly psychophysic perception r= u8PWMValue[r]; // red g= u8PWMValue[g]; // green b= u8PWMValue[b]; // blue break; case COLOR_CODING_RGB: // Adjust RGB-values accordingly psychophysic perception r=pLEDData[iLED].r < 64?u8PWMValue[pLEDData[iLED].r]:255; // red g=pLEDData[iLED].g < 64?u8PWMValue[pLEDData[iLED].g]:255; // green b=pLEDData[iLED].b < 64?u8PWMValue[pLEDData[iLED].b]:255; // blue break; case COLOR_CODING_RGB_DIRECT: default: r=pLEDData[iLED].r; // red g=pLEDData[iLED].g; // green b=pLEDData[iLED].b; // blue break; } for(i=0;i<8;i++) // for all bits in r,g and b: // if highest bit in r, g or b { // is set -> corresponding DMABuffer byte is set to 60 => 0,833µs high and 0,416µs low // if not -> corresponding DMABuffer byte is set to 30 => 0,416µs high and 0,833µs low DMABuffer[nPos+i]=(g&0x80)!=0?60:30; // first 8 byte of DMA-Buffer = green DMABuffer[nPos+i+8]=(r&0x80)!=0?60:30; // second 8 bytes of DMA-Buffer = red DMABuffer[nPos+i+16]=(b&0x80)!=0?60:30; // last 8 byte of DMA-Buffer = blue r<<=1; // g<<=1; // shift r,g,b one bit to the left -> next test will check the one lower bit b<<=1; // } iLED++; // increase iLED -> net time function called, next LED data is transfered } else // if iLED >= nLED { for(i=0;i<24;i++) DMABuffer[nPos+i]=0; // fill all 24 bytes of DMA-Buffer with Zero => pin is held low => LED-bus reset iLED++; // increase iLED } }