diff --git a/stmhal/dac.c b/stmhal/dac.c
index 3cd91cc41c..8573dcc2ad 100644
--- a/stmhal/dac.c
+++ b/stmhal/dac.c
@@ -34,6 +34,7 @@
 #include "py/runtime.h"
 #include "timer.h"
 #include "dac.h"
+#include "dma.h"
 #include "pin.h"
 #include "genhdr/pins.h"
 
@@ -216,11 +217,11 @@ STATIC mp_obj_t pyb_dac_make_new(mp_obj_t type_in, mp_uint_t n_args, mp_uint_t n
     if (dac_id == 1) {
         dac->pin = GPIO_PIN_4;
         dac->dac_channel = DAC_CHANNEL_1;
-        dac->dma_stream = DMA1_Stream5;
+        dac->dma_stream = DMA_STREAM_DAC1;
     } else if (dac_id == 2) {
         dac->pin = GPIO_PIN_5;
         dac->dac_channel = DAC_CHANNEL_2;
-        dac->dma_stream = DMA1_Stream6;
+        dac->dma_stream = DMA_STREAM_DAC2;
     } else {
         nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_ValueError, "DAC %d does not exist", dac_id));
     }
@@ -396,7 +397,7 @@ mp_obj_t pyb_dac_write_timed(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_
     DMA_Handle.State = HAL_DMA_STATE_READY;
     HAL_DMA_DeInit(&DMA_Handle);
 
-    DMA_Handle.Init.Channel = DMA_CHANNEL_7;
+    DMA_Handle.Init.Channel = DMA_CHANNEL_DAC1;  // DAC1 & DAC2 both use the same channel
     DMA_Handle.Init.Direction = DMA_MEMORY_TO_PERIPH;
     DMA_Handle.Init.PeriphInc = DMA_PINC_DISABLE;
     DMA_Handle.Init.MemInc = DMA_MINC_ENABLE;
diff --git a/stmhal/dma.h b/stmhal/dma.h
index 3e62792613..0e751757fd 100644
--- a/stmhal/dma.h
+++ b/stmhal/dma.h
@@ -24,12 +24,64 @@
  * THE SOFTWARE.
  */
 
-//TODO: Put stream/channel defs for i2c/spi/can, etc here
+// These are ordered by DMAx_Stream number, and within a stream by channel
+// number. The duplicate streams are ok as long as they aren't used at the
+// same time.
+//
+// Currently I2C and SPI are synchronous and they call dma_init/dma_deinit
+// around each transfer.
+
+// DMA1 streams
+
+#define DMA_STREAM_I2C1_RX      DMA1_Stream0
+#define DMA_CHANNEL_I2C1_RX                     DMA_CHANNEL_1
+
+#define DMA_STREAM_SPI3_RX      DMA1_Stream2
+#define DMA_CHANNEL_SPI3_RX                     DMA_CHANNEL_0
+
+#define DMA_STREAM_I2C3_RX      DMA1_Stream2
+#define DMA_CHANNEL_I2C3_RX                     DMA_CHANNEL_3
+
+#define DMA_STREAM_I2C2_RX      DMA1_Stream2
+#define DMA_CHANNEL_I2C2_RX                     DMA_CHANNEL_7
+
+#define DMA_STREAM_SPI2_RX      DMA1_Stream3
+#define DMA_CHANNEL_SPI2_RX                     DMA_CHANNEL_0
+
+#define DMA_STREAM_SPI2_TX      DMA1_Stream4
+#define DMA_CHANNEL_SPI2_TX                     DMA_CHANNEL_0
+
+#define DMA_STREAM_I2C3_TX      DMA1_Stream4
+#define DMA_CHANNEL_I2C3_TX                     DMA_CHANNEL_3
+
+#define DMA_STREAM_DAC1         DMA1_Stream5
+#define DMA_CHANNEL_DAC1                        DMA_CHANNEL_7
+
+#define DMA_STREAM_DAC2         DMA1_Stream6
+#define DMA_CHANNEL_DAC2                        DMA_CHANNEL_7
+
+#define DMA_STREAM_SPI3_TX      DMA1_Stream7
+#define DMA_CHANNEL_SPI3_TX                     DMA_CHANNEL_0
+
+#define DMA_STREAM_I2C1_TX      DMA1_Stream7
+#define DMA_CHANNEL_I2C1_TX                     DMA_CHANNEL_1
+
+#define DMA_STREAM_I2C2_TX      DMA1_Stream7
+#define DMA_CHANNEL_I2C2_TX                     DMA_CHANNEL_7
+
+// DMA2 streams
+
+#define DMA_STREAM_SPI1_RX      DMA2_Stream2
+#define DMA_CHANNEL_SPI1_RX                     DMA_CHANNEL_3
+
 #define DMA_STREAM_SDIO_RX      DMA2_Stream3
-#define DMA_CHANNEL_SDIO_RX     DMA_CHANNEL_4
+#define DMA_CHANNEL_SDIO_RX                     DMA_CHANNEL_4
+
+#define DMA_STREAM_SPI1_TX      DMA2_Stream5
+#define DMA_CHANNEL_SPI1_TX                     DMA_CHANNEL_3
 
 #define DMA_STREAM_SDIO_TX      DMA2_Stream6
-#define DMA_CHANNEL_SDIO_TX     DMA_CHANNEL_4
+#define DMA_CHANNEL_SDIO_TX                     DMA_CHANNEL_4
 
 typedef union {
     uint16_t    enabled;    // Used to test if both counters are == 0
diff --git a/stmhal/i2c.c b/stmhal/i2c.c
index 82f70471a9..c97629fd98 100644
--- a/stmhal/i2c.c
+++ b/stmhal/i2c.c
@@ -134,17 +134,17 @@ I2C_HandleTypeDef I2CHandle3 = {.Instance = NULL};
 
 STATIC const pyb_i2c_obj_t pyb_i2c_obj[] = {
     #if defined(MICROPY_HW_I2C1_SCL)
-    {{&pyb_i2c_type}, &I2CHandle1, DMA1_Stream7, DMA_CHANNEL_1, DMA1_Stream0, DMA_CHANNEL_1},
+    {{&pyb_i2c_type}, &I2CHandle1, DMA_STREAM_I2C1_TX, DMA_CHANNEL_I2C1_TX, DMA_STREAM_I2C1_RX, DMA_CHANNEL_I2C1_RX},
     #else
     {{&pyb_i2c_type}, NULL, NULL, 0, NULL, 0},
     #endif
     #if defined(MICROPY_HW_I2C2_SCL)
-    {{&pyb_i2c_type}, &I2CHandle2, DMA1_Stream7, DMA_CHANNEL_7, DMA1_Stream2, DMA_CHANNEL_7},
+    {{&pyb_i2c_type}, &I2CHandle2, DMA_STREAM_I2C2_TX, DMA_CHANNEL_I2C2_TX, DMA_STREAM_I2C2_RX, DMA_CHANNEL_I2C2_RX},
     #else
     {{&pyb_i2c_type}, NULL, NULL, 0, NULL, 0},
     #endif
     #if defined(MICROPY_HW_I2C3_SCL)
-    {{&pyb_i2c_type}, &I2CHandle3, DMA1_Stream4, DMA_CHANNEL_3, DMA1_Stream2, DMA_CHANNEL_3},
+    {{&pyb_i2c_type}, &I2CHandle3, DMA_STREAM_I2C3_TX, DMA_CHANNEL_I2C3_TX, DMA_STREAM_I2C3_RX, DMA_CHANNEL_I2C3_RX},
     #else
     {{&pyb_i2c_type}, NULL, NULL, 0, NULL, 0},
     #endif
diff --git a/stmhal/spi.c b/stmhal/spi.c
index 7458da6279..01b9665b53 100644
--- a/stmhal/spi.c
+++ b/stmhal/spi.c
@@ -114,17 +114,17 @@ SPI_HandleTypeDef SPIHandle3 = {.Instance = NULL};
 
 STATIC const pyb_spi_obj_t pyb_spi_obj[] = {
 #if MICROPY_HW_ENABLE_SPI1
-    {{&pyb_spi_type}, &SPIHandle1, DMA2_Stream5, DMA_CHANNEL_3, DMA2_Stream2, DMA_CHANNEL_3},
+    {{&pyb_spi_type}, &SPIHandle1, DMA_STREAM_SPI1_TX, DMA_CHANNEL_SPI1_TX, DMA_STREAM_SPI1_RX, DMA_CHANNEL_SPI1_RX},
 #else
     {{&pyb_spi_type}, NULL, NULL, 0, NULL, 0},
 #endif
 #if MICROPY_HW_ENABLE_SPI2
-    {{&pyb_spi_type}, &SPIHandle2, DMA1_Stream4, DMA_CHANNEL_0, DMA1_Stream3, DMA_CHANNEL_0},
+    {{&pyb_spi_type}, &SPIHandle2, DMA_STREAM_SPI2_TX, DMA_CHANNEL_SPI2_TX, DMA_STREAM_SPI2_RX, DMA_CHANNEL_SPI2_RX},
 #else
     {{&pyb_spi_type}, NULL, NULL, 0, NULL, 0},
 #endif
 #if MICROPY_HW_ENABLE_SPI3
-    {{&pyb_spi_type}, &SPIHandle3, DMA1_Stream7, DMA_CHANNEL_0, DMA1_Stream2, DMA_CHANNEL_0},
+    {{&pyb_spi_type}, &SPIHandle3, DMA_STREAM_SPI3_TX, DMA_CHANNEL_SPI3_TX, DMA_STREAM_SPI3_RX, DMA_CHANNEL_SPI3_RX},
 #else
     {{&pyb_spi_type}, NULL, NULL, 0, NULL, 0},
 #endif