Merge pull request #29 from arduino-libraries/add_set_frequency

Add set frequency

Author: iabdalkader

examples/Beginner/Waveform_Generator/Waveform_Generator.ino

@@ -55,13 +55,9 @@ void generate_waveform(int cmd)
             } else {
               break;
             }
-            
-            dac1.stop();
-            delay(500);
-            if (!dac1.begin(AN_RESOLUTION_8, dac_frequency * N_SAMPLES, N_SAMPLES, 32)) {
-              Serial.println("Failed to start DAC1 !");
-            }
-            delay(500);
+
+            // Change frequency.
+            dac1.frequency(dac_frequency * N_SAMPLES);
             break;
 
         default:

src/AdvancedDAC.cpp

@@ -182,6 +182,15 @@ int AdvancedDAC::stop()
     return 1;
 }
 
+int AdvancedDAC::frequency(uint32_t const 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 const frequency);
 };
 
 #endif /* ARDUINO_ADVANCED_DAC_H_ */