Add function to change DAC frequency on the fly.

Author: iabdalkader

src/AdvancedDAC.cpp

@@ -182,6 +182,15 @@ int AdvancedDAC::stop()
     return 1;
 }
 
+int AdvancedDAC::frequency(uint32_t frequency)
+{
+    if (descr && descr->pool) {
+        // Reconfigure the trigger timer.
+        dac_descr_deinit(descr, false);
+        hal_tim_config(&descr->tim, frequency);
+    }
+}
+
 AdvancedDAC::~AdvancedDAC()
 {
     dac_descr_deinit(descr, true);

src/AdvancedDAC.h

@@ -49,6 +49,7 @@ class AdvancedDAC {
         void write(SampleBuffer dmabuf);
         int begin(uint32_t resolution, uint32_t frequency, size_t n_samples=0, size_t n_buffers=0);
         int stop();
+        int frequency(uint32_t frequency);
 };
 
 #endif /* ARDUINO_ADVANCED_DAC_H_ */