tht-frames

diff --git a/frames/drivers/dac.cc b/frames/drivers/dac.cc
index 1b45bbc..ab0c458 100755
--- a/frames/drivers/dac.cc
+++ b/frames/drivers/dac.cc
@@ -31,12 +31,19 @@
 namespace frames {
   
 void Dac::Init() {
-  // Initialize SS pin.
+  // Initialize SS pins.
   GPIO_InitTypeDef gpio_init;
-  gpio_init.GPIO_Pin = kPinSS;
+  gpio_init.GPIO_Pin = kPinDAC1_SS | kPinDAC2_SS;
   gpio_init.GPIO_Speed = GPIO_Speed_50MHz;
   gpio_init.GPIO_Mode = GPIO_Mode_Out_PP;
-  GPIO_Init(GPIOB, &gpio_init);
+  GPIO_Init(GPIOA, &gpio_init);
+
+  // Initialize and set LDAC pin.
+  gpio_init.GPIO_Pin = kPinLDAC;
+  gpio_init.GPIO_Speed = GPIO_Speed_50MHz;
+  gpio_init.GPIO_Mode = GPIO_Mode_Out_PP;
+  GPIO_Init(GPIOA, &gpio_init);
+  GPIOA->BRR = kPinLDAC;
   
   // Initialize MOSI and SCK pins.
   gpio_init.GPIO_Pin = GPIO_Pin_13 | GPIO_Pin_15;
diff --git a/frames/drivers/dac.h b/frames/drivers/dac.h
index 9679bb3..21ca592 100755
--- a/frames/drivers/dac.h
+++ b/frames/drivers/dac.h
@@ -37,7 +37,9 @@
 
 namespace frames {
 
-const uint16_t kPinSS = GPIO_Pin_12;
+const uint16_t kPinLDAC = GPIO_Pin_8;
+const uint16_t kPinDAC1_SS = GPIO_Pin_12;
+const uint16_t kPinDAC2_SS = GPIO_Pin_11;
 
 class Dac {
  public:
@@ -49,9 +51,10 @@ class Dac {
     data_[channel] = data & 0x0fff;
   }
   void Update() {
-    GPIOB->BSRR = kPinSS;
-    GPIOB->BRR = kPinSS;
-    uint16_t command_nibble = (active_channel_ << 2) | 1;
+    uint16_t kPinSS = (active_channel_ >> 1) & 1 ? kPinDAC2_SS : kPinDAC1_SS;
+    GPIOA->BSRR = kPinSS;
+    GPIOA->BRR = kPinSS;
+    uint16_t command_nibble = ((active_channel_ & 1) << 3) | 3;
     SPI2->DR = (command_nibble << 12) | data_[active_channel_];
     active_channel_ = (active_channel_ + 1) % 4;
   }