diff --git a/firmware/Makefile b/firmware/Makefile
index ee7c9f9..91b9129 100644
--- a/firmware/Makefile
+++ b/firmware/Makefile
@@ -145,6 +145,7 @@ CPPSRC = $(ALLCPPSRC) \
           fault.cpp \
           lambda_conversion.cpp \
           pwm.cpp \
+          dac.cpp \
           pump_dac.cpp \
           sampling.cpp \
           heater_control.cpp \
diff --git a/firmware/auxout.cpp b/firmware/auxout.cpp
index bd72dd3..4644190 100644
--- a/firmware/auxout.cpp
+++ b/firmware/auxout.cpp
@@ -1,4 +1,5 @@
 #include "pwm.h"
+#include "dac.h"
 #include "lambda_conversion.h"
 #include "port.h"
 #include "io_pins.h"
@@ -58,42 +59,6 @@ void SetAuxDac(int channel, float voltage)
 
 #ifdef AUXOUT_DAC_DEVICE
 
-class Dac
-{
-public:
-    Dac(DACDriver& driver);
-
-    void Start(DACConfig& config);
-    void SetVoltage(int channel, float duty);
-    float GetLastVoltage(int channel);
-
-private:
-    DACDriver* const m_driver;
-    float m_voltageFloat[2];
-};
-
-Dac::Dac(DACDriver& driver)
-    : m_driver(&driver)
-{
-}
-
-void Dac::Start(DACConfig& config)
-{
-    dacStart(m_driver, &config);
-}
-
-void Dac::SetVoltage(int channel, float voltage) {
-    voltage = clampF(0, voltage, VCC_VOLTS);
-    m_voltageFloat[channel] = voltage;
-
-    dacPutChannelX(m_driver, channel, voltage / VCC_VOLTS * (1 << 12));
-}
-
-float Dac::GetLastVoltage(int channel)
-{
-    return m_voltageFloat[channel];
-}
-
 static DACConfig auxDacConfig = {
   .init         = 2047U,
   .datamode     = DAC_DHRM_12BIT_RIGHT,
diff --git a/firmware/dac.cpp b/firmware/dac.cpp
new file mode 100644
index 0000000..51a548a
--- /dev/null
+++ b/firmware/dac.cpp
@@ -0,0 +1,32 @@
+#include "dac.h"
+
+/* for VCC_VOLTS */
+#include "wideband_config.h"
+
+#include <rusefi/math.h>
+
+#if HAL_USE_DAC
+
+Dac::Dac(DACDriver& driver)
+    : m_driver(&driver)
+{
+}
+
+void Dac::Start(DACConfig& config)
+{
+    dacStart(m_driver, &config);
+}
+
+void Dac::SetVoltage(int channel, float voltage) {
+    voltage = clampF(0, voltage, VCC_VOLTS);
+    m_voltageFloat[channel] = voltage;
+
+    dacPutChannelX(m_driver, channel, voltage / VCC_VOLTS * (1 << 12));
+}
+
+float Dac::GetLastVoltage(int channel)
+{
+    return m_voltageFloat[channel];
+}
+
+#endif
diff --git a/firmware/dac.h b/firmware/dac.h
new file mode 100644
index 0000000..4b492f0
--- /dev/null
+++ b/firmware/dac.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <cstdint>
+
+/* for DACConfig */
+#include "hal.h"
+
+#if HAL_USE_DAC
+
+class Dac
+{
+public:
+    Dac(DACDriver& driver);
+
+    void Start(DACConfig& config);
+    void SetVoltage(int channel, float volage);
+    float GetLastVoltage(int channel);
+
+private:
+    DACDriver* const m_driver;
+    float m_voltageFloat[2];
+};
+
+#endif