snapshot

libraries/audio-tools/examples/sandbox/experiment-ads1015-serial/README.md

@@ -0,0 +1,22 @@
+# ADS1015
+
+![ADS1015](https://pschatzmann.github.io/arduino-audio-tools/doc/resources/ads1015.jpeg)
+
+The ADS1015 is a 12 bit ADC which is connected via I2C.
+
+### Pins:
+ 
+| ADS1015 | ESP32
+|---------|---------------
+| VDD     | 3.3
+| GND     | GND
+| SCL     | SCL GPIO22
+| SDA     | SDA GPIO21
+| ADDR    | GND  
+| ALRT    | -
+| A0      | Analog Source (e.g. Electic Guitar) 
+
+
+## Conclusion
+
+The sampling rate is too low to be usefull.

libraries/audio-tools/examples/sandbox/experiment-ads1015-serial/experiment-ads1015-serial.ino

@@ -0,0 +1,68 @@
+/**
+ * @file experiment-ads1015-serial.ino
+ * @author Phil Schatzmann
+ * @brief We can use the ADS1015 to provide analog signals. Unfortunatly it is not
+ * suited for audio because it is too slow.
+ * @version 0.1
+ * @date 2022-12-07
+ * 
+ * @copyright Copyright (c) 2022
+ * 
+ */
+#include "Wire.h"
+#include "Adafruit_ADS1015.h"
+#include "AudioTools.h"
+
+const int sample_rate = 3300;
+const int buffer_size = 50;
+
+Adafruit_ADS1015 ads1015(0x48);   
+TimerAlarmRepeating sound_timer;
+NBuffer<int16_t> buffer(buffer_size,3);  
+
+// callback to record the sound data into a buffer
+void write_sample(void *ptr) {
+  sound_t sample = ads1015.readADC_Differential_0_1();
+  buffer.write(sample);
+}
+
+// Arduino Setup
+void setup(void) {
+  Serial.begin(115200);
+
+  // setup microphone
+  ads1015.begin();  
+  ads1015.setGain(GAIN_SIXTEEN); // GAIN_TWO GAIN_FOUR GAIN_EIGHT GAIN_SIXTEEN
+
+  // start the timer to record the data
+  long waitUs = 1000000 / sample_rate;
+  sound_timer.start(write_sample, waitUs, US);
+
+}
+
+void printSampleRate() {
+  static long next_time;
+  if (millis()>next_time){
+     next_time = next_time+1000;
+     Serial.print("sample rate: ");
+     Serial.println(buffer.sampleRate());
+  }
+}
+
+void printSamples() {
+  static sound_t array[50][2];
+  size_t len = buffer.readFrames(array);
+  for (int j=0;j<len;j++){
+    Serial.print(array[j][0]);
+    Serial.print(" ");
+    Serial.println(array[j][1]);
+  }
+}
+
+// Arduino loop - repeated processing
+void loop() {
+  // copy sound data from samples to I2S
+  printSamples();
+  printSampleRate();
+  
+}