Implement test RX for DMX. Still no functionality

firmware/dmx.c

@@ -1,21 +1,34 @@
 #include <ring-light/dmx.h>
 #include <stm32f0xx.h>
 
-static volatile bool dmx_new_data_avail = false;
 static uint32_t dmx_base_channel;
-static uint8_t dmx_channel_data[DMX_USED_CHANNEL_COUNT];
+
+enum dmx_rx_state_enum {
+	DMX_RX_WAIT_FOR_BREAK = 0,
+	DMX_RX_DATA,
+};
+
+/**
+ * @brief DMX data received. Contains the whole DMX universe including the first 0 byte.
+ * The controller does check the first byte to be zero.
+ */
+static volatile uint8_t dmx_channel_data[DMX_UNIVERSE_SIZE + 1];
+
+static volatile enum dmx_rx_state_enum dmx_rx_state;
+static volatile uint32_t dmx_write_pointer;
 
 void dmx_init(uint32_t base_channel)
 {
 	int i;
-	uint8_t *ptr;
+	volatile uint8_t *ptr;
 
-	dmx_new_data_avail = false;
 	for (i = 0, ptr = dmx_channel_data; i < DMX_USED_CHANNEL_COUNT; i++, ptr++) {
 		*ptr = 0u;
 	}
 
 	dmx_base_channel = base_channel;
+	dmx_write_pointer = 0u;
+	dmx_rx_state = DMX_RX_WAIT_FOR_BREAK;
 
 	/* Enable GPIOA and USART1 clock */
 	RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
@@ -35,31 +48,52 @@ void dmx_init(uint32_t base_channel)
 	USART1->CR2 = USART_CR2_STOP_1;
 	USART1->CR1 = USART_CR1_RXNEIE | USART_CR1_RE | USART_CR1_UE;
 
+	/* Map USART1 RX to DMA Channel 3 */
+	SYSCFG->CFGR1 &= ~SYSCFG_CFGR1_USART1RX_DMA_RMP;
+
 	NVIC_EnableIRQ(USART1_IRQn);
 }
 
-bool dmx_new_data_available()
-{
-	return dmx_new_data_avail;
-}
 
 const uint8_t *dmx_get_data()
 {
-	return dmx_channel_data;
+	return (const uint8_t *)&dmx_channel_data[1];
 }
 
 void USART1_IRQHandler(void)
 {
 	uint32_t isr;
-	volatile uint8_t dreg;
+	uint8_t dreg;
 
 	isr = USART1->ISR;
 	USART1->ICR = USART_ICR_ORECF | USART_ICR_NCF | USART_ICR_FECF;
 
-	if (isr & USART_ISR_RXNE) {
+	if (isr & USART_ISR_FE) {
+		/* Frame error received. Start of DMX frame */
+		dmx_write_pointer = 0u;
+		dmx_rx_state = DMX_RX_DATA;
+		/* Flush RX data */
+		USART1->RQR = USART_RQR_RXFRQ;
+	} else if (isr & USART_ISR_RXNE) {
+		/* Received valid symbol */
 		dreg = (uint8_t)USART1->RDR;
-		dmx_channel_data[0] = dreg;
+
+		if (dmx_rx_state == DMX_RX_DATA) {
+			/* Ready to recieve data */
+			if (dmx_write_pointer < (DMX_UNIVERSE_SIZE + 1)) {
+				dmx_channel_data[dmx_write_pointer] = dreg;
+				dmx_write_pointer++;
+			} else {
+				dmx_rx_state = DMX_RX_WAIT_FOR_BREAK;
+			}
+		}
+
 	}
 
 	__DSB();
 }
+
+void DMA_CH2_3_DMA2_CH1_2_IRQHandler()
+{
+
+}

firmware/include/ring-light/dmx.h

@@ -28,12 +28,6 @@
  */
 void dmx_init(uint32_t base_channel);
 
-/**
- * @brief Has new DMX data been received?
- * @return true if new data is available
- */
-bool dmx_new_data_available(void);
-
 /**
  * @brief Returns the array of the 129 DMX channels
  * @return

firmware/temp-adc.c

@@ -96,7 +96,7 @@ void DMA_CH1_IRQHandler(void)
 	uint32_t isr;
 	
 	isr = DMA1->ISR;
-	DMA1->IFCR = isr;
+	DMA1->IFCR = isr & 0xF;
 
 	if (isr & DMA_ISR_TCIF1) {
 		process_adc_samples();