From 8dc30f15fbd5c16c5bfe2af18b7bab96d898f460 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mario=20H=C3=BCttel?= <mario.huettel@gmx.net>
Date: Thu, 7 Jul 2022 17:40:25 +0200
Subject: [PATCH] Implement first working version of DMX receiver. Might still
 be buggy

---
 firmware/dmx.c                    | 14 ++++++++++++--
 firmware/include/ring-light/dmx.h |  2 +-
 firmware/main.c                   |  6 +++---
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/firmware/dmx.c b/firmware/dmx.c
index 16636cc..82da070 100644
--- a/firmware/dmx.c
+++ b/firmware/dmx.c
@@ -3,11 +3,15 @@
 
 static uint32_t dmx_base_channel;
 
+
 enum dmx_rx_state_enum {
 	DMX_RX_WAIT_FOR_BREAK = 0,
 	DMX_RX_DATA,
 };
 
+static volatile enum dmx_rx_state_enum dmx_state;
+
+
 static volatile bool break_received;
 
 /**
@@ -71,17 +75,22 @@ void USART1_IRQHandler(void)
 	if (isr & USART_ISR_FE) {
 		/* Frame error received. Start of DMX frame */
 		/* Flush RX data */
+		USART1->CR3 &= ~USART_CR3_DMAR;
 		USART1->RQR = USART_RQR_RXFRQ;
-		USART1->CR3 |= USART_CR3_DMAR;
 		DMA1_Channel3->CCR &= ~DMA_CCR_EN;
+		while (DMA1_Channel3->CCR & DMA_CCR_EN);
 		DMA1_Channel3->CMAR = (uint32_t)dmx_channel_data;
 		DMA1_Channel3->CPAR = (uint32_t)&USART1->RDR;
 		DMA1_Channel3->CNDTR = DMX_UNIVERSE_SIZE + 1;
 		DMA1_Channel3->CCR |= DMA_CCR_EN;
+		USART1->RQR = USART_RQR_RXFRQ;
 		USART1->CR3 |= USART_CR3_DMAR;
 		break_received = true;
+		dmx_state = DMX_RX_DATA;
 	} else if (isr & USART_ISR_RXNE) {
-
+		if (dmx_state != DMX_RX_DATA) {
+			USART1->RQR = USART_RQR_RXFRQ;
+		}
 	}
 
 	__DSB();
@@ -97,6 +106,7 @@ void DMA_CH2_3_DMA2_CH1_2_IRQHandler(void)
 
 	if (isr & DMA_ISR_TCIF3) {
 		DMA1->ISR;
+		dmx_state = DMX_RX_WAIT_FOR_BREAK;
 	}
 	__DSB();
 }
diff --git a/firmware/include/ring-light/dmx.h b/firmware/include/ring-light/dmx.h
index 68970db..6fdcbf1 100644
--- a/firmware/include/ring-light/dmx.h
+++ b/firmware/include/ring-light/dmx.h
@@ -6,7 +6,7 @@
 #include <stdint.h>
 #include <stdbool.h>
 
-#define DMX_UNIVERSE_SIZE (255u)
+#define DMX_UNIVERSE_SIZE (512u)
 #define DMX_USED_CHANNEL_COUNT (129u)
 
 /**
diff --git a/firmware/main.c b/firmware/main.c
index add76ee..34d978a 100644
--- a/firmware/main.c
+++ b/firmware/main.c
@@ -220,9 +220,9 @@ int main(void)
 			last_led_val = led_val;
 		}
 
-
-
-		wait_for_ticks(5);
+		/* Only wait in case of non-DMX mode */
+		if (!(mode == RING_MODE_WAIT_DMX_BREAK || mode == RING_MODE_WAIT_DMX))
+			wait_for_ticks(5);
 
 		if((int16_t)TIM3->CNT > (int16_t)led_val) {
 			led_val = 0u;