switching the frequency between 440 and 880 every second

test-pico-io/src/main.cpp

@@ -10,6 +10,9 @@ I2S i2s(OUTPUT);
 #define BLOCKSIZE 64                 // Heavy block size
 #define BUFFERSIZE (2 * BLOCKSIZE)   // Stereo interleaved
 
+bool state;
+int delta;
+
 int16_t buffer[BUFFERSIZE];
 
 inline int16_t float_to_i16(float x) {
@@ -75,5 +78,12 @@ void setup() {
 }
 
 void loop() {
-  
+  if (millis() - delta > 1000) {
+    int freq;
+    if (state) freq = 440;
+    else freq = 880;
+    hv->sendFloatToReceiver(hv_string_to_hash("osc_freq_input"), freq);
+    state = !state;
+    delta = millis();
+  }
 }