serial wip

1 files changed, 19 insertions, 6 deletions

diff --git a/gm_platform/fw/adc.c b/gm_platform/fw/adc.c
index 547089b..2a33171 100644
--- a/gm_platform/fw/adc.c
+++ b/gm_platform/fw/adc.c
@@ -16,11 +16,14 @@
  */
 
 #include "adc.h"
+#include "serial.h"
 
 #include <stdbool.h>
 #include <stdlib.h>
+#include <assert.h>
 
-volatile uint16_t adc_buf[ADC_BUFSIZE];
+volatile uint16_t adc_buf[100]; /* 100ms worth of data */
+uint32_t usart_overruns = 0;
 
 static void adc_dma_init(int burstlen);
 static void adc_timer_init(int psc, int ivl);
@@ -56,9 +59,6 @@ void adc_configure_scope_mode(int sampling_interval_ns) {
 	adc_timer_init(12/*250ns/tick*/, cycles);
 }
 
-/* FIXME figure out the proper place to configure this. */
-#define ADC_TIMER_INTERVAL_US 20
-
 static void adc_dma_init(int burstlen) {
     /* Configure DMA 1 Channel 1 to get rid of all the data */
     DMA1_Channel1->CPAR = (unsigned int)&ADC1->DR;
@@ -70,11 +70,12 @@ static void adc_dma_init(int burstlen) {
         | (1<<DMA_CCR_MSIZE_Pos) /* 16 bit */
         | (1<<DMA_CCR_PSIZE_Pos) /* 16 bit */
         | DMA_CCR_MINC
+        | DMA_CCR_HTIE  /* Enable half-transfer interrupt. */
         | DMA_CCR_TCIE; /* Enable transfer complete interrupt. */
 
-    /* triggered on transfer completion. We use this to process the ADC data */
+    /* triggered on half-transfer and on transfer completion. We use this to send out the ADC data and to trap into GDB. */
     NVIC_EnableIRQ(DMA1_Channel1_IRQn);
-    NVIC_SetPriority(DMA1_Channel1_IRQn, 2<<5);
+    NVIC_SetPriority(DMA1_Channel1_IRQn, 3<<5);
 
     DMA1_Channel1->CCR |= DMA_CCR_EN; /* Enable channel */
 }
@@ -99,9 +100,21 @@ static void gdb_dump(void) {
 }
 
 void DMA1_Channel1_IRQHandler(void) {
+    uint32_t isr = DMA1->ISR;
     /* Clear the interrupt flag */
     DMA1->IFCR |= DMA_IFCR_CGIF1;
+
     gdb_dump();
+    static_assert(ARRAY_LEN(adc_buf) % 2 == 0, "ADC_BUFSIZE must be even for half-transfer uart tx logic to work");
+
+    int rc;
+    if (isr & DMA_ISR_HTIF2) /* half-transfer */
+        rc = usart_send_packet_nonblocking((uint8_t *)adc_buf, sizeof(adc_buf)/2);
+    else /* end of transfer */
+        rc = usart_send_packet_nonblocking((uint8_t *)adc_buf + ARRAY_LEN(adc_buf)/2, sizeof(adc_buf)/2);
+
+    if (rc)
+        usart_overruns++;
     
     /*
     static int debug_buf_pos = 0;