diff --git a/os/hal/ports/STM32/LLD/DACv1/dac_lld.c b/os/hal/ports/STM32/LLD/DACv1/dac_lld.c
index 8fc51ae88..f3191e47b 100644
--- a/os/hal/ports/STM32/LLD/DACv1/dac_lld.c
+++ b/os/hal/ports/STM32/LLD/DACv1/dac_lld.c
@@ -253,9 +253,16 @@ void dac_lld_start(DACDriver *dacp) {
     dacp->params->dac->CR |= DAC_CR_EN1 << dacp->params->regshift;
     dac_lld_put_channel(dacp, 0U, dacp->config->init);
 #else
-    dacp->params->dac->CR = DAC_CR_EN2 | DAC_CR_EN1;
+    if ((dacp->config->datamode == DAC_DHRM_12BIT_RIGHT_DUAL) ||
+        (dacp->config->datamode == DAC_DHRM_12BIT_LEFT_DUAL) ||
+        (dacp->config->datamode == DAC_DHRM_8BIT_RIGHT_DUAL)) {
+      dacp->params->dac->CR = DAC_CR_EN2 | DAC_CR_EN1;
+      dac_lld_put_channel(dacp, 1U, dacp->config->init);
+    }
+    else {
+      dacp->params->dac->CR = DAC_CR_EN1;
+    }
     dac_lld_put_channel(dacp, 0U, dacp->config->init);
-    dac_lld_put_channel(dacp, 1U, dacp->config->init);
 #endif
   }
 }
@@ -308,6 +315,7 @@ void dac_lld_put_channel(DACDriver *dacp,
 
   switch (dacp->config->datamode) {
   case DAC_DHRM_12BIT_RIGHT:
+  case DAC_DHRM_12BIT_RIGHT_DUAL:
     if (channel == 0U) {
       dacp->params->dac->DHR12R1 = (uint32_t)sample;
     }
@@ -316,6 +324,7 @@ void dac_lld_put_channel(DACDriver *dacp,
     }
     break;
   case DAC_DHRM_12BIT_LEFT:
+  case DAC_DHRM_12BIT_LEFT_DUAL:
     if (channel == 0U) {
       dacp->params->dac->DHR12L1 = (uint32_t)sample;
     }
@@ -324,6 +333,7 @@ void dac_lld_put_channel(DACDriver *dacp,
     }
     break;
   case DAC_DHRM_8BIT_RIGHT:
+  case DAC_DHRM_8BIT_RIGHT_DUAL:
     if (channel == 0U) {
       dacp->params->dac->DHR8R1  = (uint32_t)sample;
     }
@@ -340,13 +350,24 @@ void dac_lld_put_channel(DACDriver *dacp,
 /**
  * @brief   Starts a DAC conversion.
  * @details Starts an asynchronous conversion operation.
+ * @note    In @p DAC_DHRM_8BIT_RIGHT mode the parameters passed to the
+ *          callback are wrong because two samples are packed in a single
+ *          dacsample_t element. This will not be corrected, do not rely
+ *          on those parameters.
+ * @note    In @p DAC_DHRM_8BIT_RIGHT_DUAL mode two samples are treated
+ *          as a single 16 bits sample and packed into a single dacsample_t
+ *          element. The num_channels must be set to one in the group
+ *          conversion configuration structure.
  *
  * @param[in] dacp      pointer to the @p DACDriver object
  *
  * @notapi
  */
 void dac_lld_start_conversion(DACDriver *dacp) {
-  uint32_t cr, dmamode;
+  uint32_t n, cr, dmamode;
+
+  /* Number of DMA operations per buffer.*/
+  n = dacp->depth * dacp->grpp->num_channels;
 
   /* Allocating the DMA channel.*/
   bool b = dmaStreamAllocate(dacp->params->dma, dacp->params->dmairqprio,
@@ -354,53 +375,67 @@ void dac_lld_start_conversion(DACDriver *dacp) {
                              (void *)dacp);
   osalDbgAssert(!b, "stream already allocated");
 
-#if STM32_DAC_DUAL_MODE == FALSE
+  /* DMA settings depend on the chosed DAC mode.*/
   switch (dacp->config->datamode) {
   /* Sets the DAC data register */
   case DAC_DHRM_12BIT_RIGHT:
+    osalDbgAssert(dacp->grpp->num_channels == 1, "invalid number of channels");
+
     dmaStreamSetPeripheral(dacp->params->dma, &dacp->params->dac->DHR12R1 +
                                               dacp->params->dataoffset);
     dmamode = dacp->params->dmamode |
               STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
     break;
   case DAC_DHRM_12BIT_LEFT:
+    osalDbgAssert(dacp->grpp->num_channels == 1, "invalid number of channels");
+
     dmaStreamSetPeripheral(dacp->params->dma, &dacp->params->dac->DHR12L1 +
                                               dacp->params->dataoffset);
     dmamode = dacp->params->dmamode |
               STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
     break;
   case DAC_DHRM_8BIT_RIGHT:
+    osalDbgAssert(dacp->grpp->num_channels == 1, "invalid number of channels");
+
     dmaStreamSetPeripheral(dacp->params->dma, &dacp->params->dac->DHR8R1 +
                                               dacp->params->dataoffset);
     dmamode = dacp->params->dmamode |
               STM32_DMA_CR_PSIZE_BYTE | STM32_DMA_CR_MSIZE_BYTE;
+
+    /* In this mode the size of the buffer is halved because two samples
+       packed in a single dacsample_t element.*/
+    n = (n + 1) / 2;
     break;
+#if STM32_DAC_DUAL_MODE == TRUE
+  case DAC_DHRM_12BIT_RIGHT_DUAL:
+    osalDbgAssert(dacp->grpp->num_channels == 2, "invalid number of channels");
+
+    dmaStreamSetPeripheral(dacp->params->dma, &dacp->params->dac->DHR12RD);
+    dmamode = dacp->params->dmamode |
+              STM32_DMA_CR_PSIZE_WORD | STM32_DMA_CR_MSIZE_WORD;
+    break;
+  case DAC_DHRM_12BIT_LEFT_DUAL:
+    osalDbgAssert(dacp->grpp->num_channels == 2, "invalid number of channels");
+
+    dmaStreamSetPeripheral(dacp->params->dma, &dacp->params->dac->DHR12LD);
+    dmamode = dacp->params->dmamode |
+              STM32_DMA_CR_PSIZE_WORD | STM32_DMA_CR_MSIZE_WORD;
+    break;
+  case DAC_DHRM_8BIT_RIGHT_DUAL:
+    osalDbgAssert(dacp->grpp->num_channels == 1, "invalid number of channels");
+
+    dmaStreamSetPeripheral(dacp->params->dma, &dacp->params->dac->DHR8RD);
+    dmamode = dacp->params->dmamode |
+              STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
+    break;
+#endif
   default:
     chDbgAssert(false, "unexpected DAC mode");
     break;
   }
-#else
-#if defined(STM32_HAS_DAC_CHN2) && STM32_HAS_DAC_CHN2
-      case DAC_DHRM_12BIT_RIGHT_DUAL:
-        dmaStreamSetPeripheral(dacp->dma, &dacp->dac->DHR12RD);
-        dacp->dmamode = (dacp->dmamode & ~STM32_DMA_CR_SIZE_MASK) |
-              STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
-        break;
-      case DAC_DHRM_12BIT_LEFT_DUAL:
-        dmaStreamSetPeripheral(dacp->dma, &dacp->dac->DHR12LD);
-        dacp->dmamode = (dacp->dmamode & ~STM32_DMA_CR_SIZE_MASK) |
-              STM32_DMA_CR_PSIZE_HWORD | STM32_DMA_CR_MSIZE_HWORD;
-        break;
-      case DAC_DHRM_8BIT_RIGHT_DUAL:
-        dmaStreamSetPeripheral(dacp->dma, &dacp->dac->DHR8RD);
-        dacp->dmamode = (dacp->dmamode & ~STM32_DMA_CR_SIZE_MASK) |
-             STM32_DMA_CR_PSIZE_BYTE | STM32_DMA_CR_MSIZE_BYTE;
-        break;
-#endif
-#endif
 
   dmaStreamSetMemory0(dacp->params->dma, dacp->samples);
-  dmaStreamSetTransactionSize(dacp->params->dma, dacp->depth);
+  dmaStreamSetTransactionSize(dacp->params->dma, n);
   dmaStreamSetMode(dacp->params->dma, dmamode |
                               STM32_DMA_CR_DMEIE | STM32_DMA_CR_TEIE |
                               STM32_DMA_CR_HTIE  | STM32_DMA_CR_TCIE);
@@ -412,11 +447,13 @@ void dac_lld_start_conversion(DACDriver *dacp) {
   dacp->params->dac->CR &= dacp->params->regmask;
   dacp->params->dac->CR |= cr << dacp->params->regshift;
 #else
-  /* TODO: Dual.*/
+  dacp->params->dac->CR = 0;
+  cr = DAC_CR_DMAEN1 | (dacp->grpp->trigger << 3)  | DAC_CR_TEN1 | DAC_CR_EN1
+                     | (dacp->grpp->trigger << 19) | DAC_CR_TEN2 | DAC_CR_EN2;
+  dacp->params->dac->CR = cr;
 #endif
 }
 
-
 /**
  * @brief   Stops an ongoing conversion.
  * @details This function stops the currently ongoing conversion and returns
@@ -436,10 +473,15 @@ void dac_lld_stop_conversion(DACDriver *dacp) {
 #if STM32_DAC_DUAL_MODE == FALSE
   dacp->params->dac->CR &= dacp->params->regmask;
   dacp->params->dac->CR |= DAC_CR_EN1 << dacp->params->regshift;
-  *(&dacp->params->dac->DHR12R1 + dacp->params->dataoffset) = 0U;
 #else
-  dacp->params->dac->CR = DAC_CR_EN2 | DAC_CR_EN1;
-  dacp->params->dac->DAC_DHR12RD = 0U;
+  if ((dacp->config->datamode == DAC_DHRM_12BIT_RIGHT_DUAL) ||
+      (dacp->config->datamode == DAC_DHRM_12BIT_LEFT_DUAL) ||
+      (dacp->config->datamode == DAC_DHRM_8BIT_RIGHT_DUAL)) {
+    dacp->params->dac->CR = DAC_CR_EN2 | DAC_CR_EN1;
+  }
+  else {
+    dacp->params->dac->CR = DAC_CR_EN1;
+  }
 #endif
 }
 
diff --git a/testhal/STM32/STM32F4xx/DAC_DUAL/debug/STM32F4xx-DAC_DUAL (OpenOCD, Flash and Run).launch b/testhal/STM32/STM32F4xx/DAC_DUAL/debug/STM32F4xx-DAC_DUAL (OpenOCD, Flash and Run).launch
index a6cdd3e04..cf2bb94e6 100644
--- a/testhal/STM32/STM32F4xx/DAC_DUAL/debug/STM32F4xx-DAC_DUAL (OpenOCD, Flash and Run).launch	
+++ b/testhal/STM32/STM32F4xx/DAC_DUAL/debug/STM32F4xx-DAC_DUAL (OpenOCD, Flash and Run).launch	
@@ -33,7 +33,7 @@
 <intAttribute key="org.eclipse.cdt.launch.ATTR_BUILD_BEFORE_LAUNCH_ATTR" value="2"/>
 <stringAttribute key="org.eclipse.cdt.launch.COREFILE_PATH" value=""/>
 <stringAttribute key="org.eclipse.cdt.launch.DEBUGGER_REGISTER_GROUPS" value=""/>
-<stringAttribute key="org.eclipse.cdt.launch.FORMAT" value="&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;no&quot;?&gt;&lt;contentList&gt;&lt;content id=&quot;cr2-adc_lld_start_conversion-(format)&quot; val=&quot;4&quot;/&gt;&lt;content id=&quot;CR2-adc-null-port_wait_for_interrupt-(format)&quot; val=&quot;4&quot;/&gt;&lt;content id=&quot;CR2-adc-adcp-adc_lld_start_conversion-(format)&quot; val=&quot;4&quot;/&gt;&lt;/contentList&gt;"/>
+<stringAttribute key="org.eclipse.cdt.launch.FORMAT" value="&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;no&quot;?&gt;&lt;contentList&gt;&lt;content id=&quot;CR2-adc-adcp-adc_lld_start_conversion-(format)&quot; val=&quot;4&quot;/&gt;&lt;content id=&quot;CR2-adc-null-port_wait_for_interrupt-(format)&quot; val=&quot;4&quot;/&gt;&lt;content id=&quot;cr2-adc_lld_start_conversion-(format)&quot; val=&quot;4&quot;/&gt;&lt;/contentList&gt;"/>
 <stringAttribute key="org.eclipse.cdt.launch.GLOBAL_VARIABLES" value="&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;no&quot;?&gt;&#13;&#10;&lt;globalVariableList/&gt;&#13;&#10;"/>
 <stringAttribute key="org.eclipse.cdt.launch.MEMORY_BLOCKS" value="&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot; standalone=&quot;no&quot;?&gt;&#13;&#10;&lt;memoryBlockExpressionList/&gt;&#13;&#10;"/>
 <stringAttribute key="org.eclipse.cdt.launch.PROGRAM_NAME" value="./build/ch.elf"/>
diff --git a/testhal/STM32/STM32F4xx/DAC_DUAL/main.c b/testhal/STM32/STM32F4xx/DAC_DUAL/main.c
index e57d8a3f2..b6d46b284 100644
--- a/testhal/STM32/STM32F4xx/DAC_DUAL/main.c
+++ b/testhal/STM32/STM32F4xx/DAC_DUAL/main.c
@@ -89,11 +89,11 @@ static void error_cb1(DACDriver *dacp, dacerror_t err) {
 
 static const DACConfig dac1cfg1 = {
   init:         2047U,
-  datamode:     DAC_DHRM_12BIT_RIGHT
+  datamode:     DAC_DHRM_12BIT_RIGHT_DUAL
 };
 
 static const DACConversionGroup dacgrpcfg1 = {
-  num_channels: 1U,
+  num_channels: 2U,
   end_cb:       end_cb1,
   error_cb:     error_cb1,
   trigger:      DAC_TRG(0)
@@ -125,10 +125,11 @@ int main(void) {
   chSysInit();
 
   /*
-   * Starting DAC1 driver, setting up the output pin as analog as suggested
+   * Starting DAC1 driver, setting up the output pins as analog as suggested
    * by the Reference Manual.
    */
   palSetPadMode(GPIOA, 4, PAL_MODE_INPUT_ANALOG);
+  palSetPadMode(GPIOA, 5, PAL_MODE_INPUT_ANALOG);
   dacStart(&DACD1, &dac1cfg1);
 
   /*
@@ -138,8 +139,10 @@ int main(void) {
 
   /*
    * Starting a continuous conversion.
+   * Note, the buffer size is divided by two because two elements are fetched
+   * for each transfer.
    */
-  dacStartConversion(&DACD1, &dacgrpcfg1, dac_buffer, DAC_BUFFER_SIZE);
+  dacStartConversion(&DACD1, &dacgrpcfg1, dac_buffer, DAC_BUFFER_SIZE / 2U);
   gptStartContinuous(&GPTD6, 2U);
 
   /*
diff --git a/testhal/STM32/STM32F4xx/DAC_DUAL/mcuconf.h b/testhal/STM32/STM32F4xx/DAC_DUAL/mcuconf.h
index a6bc10980..d16ac4194 100644
--- a/testhal/STM32/STM32F4xx/DAC_DUAL/mcuconf.h
+++ b/testhal/STM32/STM32F4xx/DAC_DUAL/mcuconf.h
@@ -93,9 +93,9 @@
 /*
  * DAC driver system settings.
  */
-#define STM32_DAC_DUAL_MODE                 FALSE
+#define STM32_DAC_DUAL_MODE                 TRUE
 #define STM32_DAC_USE_DAC1_CH1              TRUE
-#define STM32_DAC_USE_DAC1_CH2              TRUE
+#define STM32_DAC_USE_DAC1_CH2              FALSE
 #define STM32_DAC1_CH1_IRQ_PRIORITY         10
 #define STM32_DAC1_CH2_IRQ_PRIORITY         10
 #define STM32_DAC1_CH1_DMA_PRIORITY         2