Merge pull request #54 from etherkit/v2.0.7

Change set_freq() for auto output enable on 1st call only

Author: NT7S

README.md

@@ -666,6 +666,10 @@ This library does not currently support the spread spectrum function of the Si53
 Changelog
 ---------
 
+* v2.0.7
+
+    * Change _set_freq()_ behavior so that the output is only automatically enabled the very first time that _set_freq()_ is called
+
 * v2.0.6
 
     * Call _set_pll()_ in _set_correction()_ to ensure that the new correction factor is applied

src/si5351.cpp

@@ -125,7 +125,6 @@ void Si5351::reset(void)
 	si5351_write(22, 0x80);
 	si5351_write(23, 0x80);
 
-
 	// Turn the clocks back on...
 	si5351_write(16, 0x0c);
 	si5351_write(17, 0x0c);
@@ -174,6 +173,7 @@ void Si5351::reset(void)
 	{
 		clk_freq[i] = 0;
 		output_enable((enum si5351_clock)i, 0);
+		clk_first_set[i] = false;
 	}
 }
 
@@ -231,8 +231,12 @@ uint8_t Si5351::set_freq(uint64_t freq, enum si5351_clock clk)
 				}
 			}
 
-			// Enable the output
-			output_enable(clk, 1);
+			// Enable the output on first set_freq only
+			if(clk_first_set[(uint8_t)clk] == false)
+			{
+				output_enable(clk, 1);
+				clk_first_set[(uint8_t)clk] = true;
+			}
 
 			// Set the freq in memory
 			clk_freq[(uint8_t)clk] = freq;
@@ -284,8 +288,12 @@ uint8_t Si5351::set_freq(uint64_t freq, enum si5351_clock clk)
 		{
 			clk_freq[(uint8_t)clk] = freq;
 
-			// Enable the output
-			output_enable(clk, 1);
+			// Enable the output on first set_freq only
+			if(clk_first_set[(uint8_t)clk] == false)
+			{
+				output_enable(clk, 1);
+				clk_first_set[(uint8_t)clk] = true;
+			}
 
 			// Select the proper R div value
 			r_div = select_r_div(&freq);
@@ -416,9 +424,6 @@ uint8_t Si5351::set_freq(uint64_t freq, enum si5351_clock clk)
 			}
 		}
 
-		// Enable the output
-		output_enable(clk, 1);
-
 		div_by_4 = 0;
 		int_mode = 0;
 

src/si5351.h

@@ -308,6 +308,7 @@ class Si5351
 	struct Si5351Status dev_status;
 	struct Si5351IntStatus dev_int_status;
 	enum si5351_pll pll_assignment[8];
+  bool clk_first_set[8];
 	uint64_t clk_freq[8];
 	uint64_t plla_freq;
 	uint64_t pllb_freq;