updated examples

* speaker off

* BlackOut help light added

* I2C tester added

* M5Stack Fire microphone spectrum ananlyser added

* Hall sensor example added

Author: ChrisMicro

examples/Advanced/ESP32internalHallSensorTFT/ESP32internalHallSensorTFT.ino

@@ -0,0 +1,93 @@
+/************************************************************************
+
+  M5StackFire internal Hall sensor example
+
+  The ESP32 MCU has build in Hall sensor.
+  It is not very suscescible but if you bring a magnet close to the
+  upper screen you will see the influence on the measurement.
+  In this example we use some low pass filters to get rid of the noise.
+
+  Hardware M5StackFire         
+  Oktober 2018, ChrisMicro
+
+************************************************************************/
+#include <M5Stack.h>
+
+#define M5STACKFIRE_SPEAKER_PIN 25 // speaker DAC, only 8 Bit
+
+#define HORIZONTAL_RESOLUTION 320
+#define VERTICAL_RESOLUTION   240
+#define POSITION_OFFSET_Y      20
+#define SIGNAL_LENGTH HORIZONTAL_RESOLUTION
+
+uint16_t oldSignal[SIGNAL_LENGTH];
+uint16_t adcBuffer[SIGNAL_LENGTH];
+
+float ESP32_hallRead()
+{
+  float value = 0;
+  int count = 400;
+  // mean value filter
+  for (int n = 0; n < count; n++) value += hallRead();
+  return value / count * 10; 
+}
+
+float HallOffset = 0;
+
+void setup()
+{
+  dacWrite(M5STACKFIRE_SPEAKER_PIN, 0); // make sure that the speaker is quite
+  M5.Lcd.begin();
+  M5.Lcd.fillScreen( BLACK );
+  M5.Lcd.fillRect(10, 1, 150, 160, BLACK);
+  M5.Lcd.setCursor(0, 0);
+  M5.Lcd.setTextColor(BLUE, BLACK);
+  M5.Lcd.setTextSize(2);
+
+  M5.Lcd.println("ESP32 Hall sensor:");
+  HallOffset = ESP32_hallRead(); // callibrate the output value to the magnetic field at start up
+  M5.Lcd.setTextSize(2);
+}
+
+float LowPassFilteredValue=0;
+void showSignal()
+{
+  int n;
+
+  int oldx;
+  int oldy;
+  int oldSig;
+  int x, y;
+
+  for (n = 0; n < SIGNAL_LENGTH; n++)
+  {
+    x = n;
+    float value = ESP32_hallRead()- HallOffset;
+    LowPassFilteredValue+=(value-LowPassFilteredValue)*0.05;
+    M5.Lcd.setCursor(220, 1);
+    M5.Lcd.print((int)LowPassFilteredValue);M5.Lcd.print("    ");
+    
+    y = map(value , -127, 127, VERTICAL_RESOLUTION, POSITION_OFFSET_Y);
+
+    if (n > 0)
+    {
+      // delete old line element
+      M5.Lcd.drawLine(oldx , oldSig, x, oldSignal[n], BLACK );
+
+      // draw new line element
+      if (n < SIGNAL_LENGTH - 1) // don't draw last element because it would generate artifacts
+      {
+        M5.Lcd.drawLine(oldx,    oldy, x,            y, GREEN );
+      }
+    }
+    oldx = x;
+    oldy = y;
+    oldSig = oldSignal[n];
+    oldSignal[n] = y;
+  }
+}
+
+void loop(void)
+{
+  showSignal();
+}

examples/Advanced/I2C_Tester/I2C_Tester.ino

@@ -0,0 +1,62 @@
+/************************************************************************
+
+  M5StackFire I2C Scanner
+
+  The M5StackFire has a connector for I2C devices. 
+  This program scans the addresses 1-127 continuosly and shows 
+  the devices found on the TFT.
+
+  The M5Stack fire has two internal I2C devices at address 0x68 and 0x75.
+  
+  If they do not appear on the TFT it could mean you made a short cut on 
+  the I2C bus.
+
+  October 2018, ChrisMicro
+
+************************************************************************/
+#include <M5Stack.h>
+
+void setup() 
+{
+  M5.Lcd.begin();
+  M5.Lcd.fillScreen( BLACK );
+  M5.Lcd.setCursor(0, 0);
+  M5.Lcd.setTextColor(YELLOW);  
+  M5.Lcd.setTextSize(2);
+
+  M5.Lcd.fillScreen( BLACK );
+  M5.Lcd.setCursor(0, 0);
+  M5.Lcd.println("M5StackFire I2C Tester");
+    
+  Wire.begin();
+
+  delay(3000);
+  M5.Lcd.fillScreen( BLACK );
+}
+
+int textColor=YELLOW;
+
+void loop() 
+{
+  int address;
+  int error;
+  M5.Lcd.setCursor(0, 0);
+  M5.Lcd.println("scanning Address [HEX]");
+  
+  for(address = 1; address < 127; address++ ) 
+  {
+    Wire.beginTransmission(address);
+    error = Wire.endTransmission();
+    if(error==0)
+    {
+      M5.Lcd.print(address,HEX);M5.Lcd.print(" ");
+    }
+    else M5.Lcd.print(".");
+
+    delay(10);
+  }
+
+  if(textColor==YELLOW) textColor=GREEN;
+  else textColor=YELLOW;
+  M5.Lcd.setTextColor(textColor,BLACK);  
+}

examples/Fire/M5StackFire_BlackOutHelp/M5StackFire_BlackOutHelp.ino

@@ -0,0 +1,43 @@
+/************************************************************************
+
+  M5StackFire BlackOut Help
+
+  Here in this region we have a BlackOut.
+
+  Fortunatelly I have the M5StackFire with a little spare energie in its
+  batttery. With this I can illumnate my room ...        
+  
+  4.October 2018, ChrisMicro, Swizerland, close to Zürich
+
+************************************************************************/
+#include <M5Stack.h>
+
+#define USENEOLED
+
+#ifdef USENEOLED
+  #include <Adafruit_NeoPixel.h>
+  
+  #define M5STACK_FIRE_NEO_NUM_LEDS 10
+  #define M5STACK_FIRE_NEO_DATA_PIN 15
+  
+  Adafruit_NeoPixel pixels = Adafruit_NeoPixel(M5STACK_FIRE_NEO_NUM_LEDS, M5STACK_FIRE_NEO_DATA_PIN, NEO_GRB + NEO_KHZ800);
+#endif
+
+void setup()
+{
+  M5.Lcd.begin();
+  M5.Lcd.fillScreen( WHITE );
+
+  #ifdef USENEOLED
+    pixels.begin(); 
+    int r=255;
+    int g=255;
+    int b=255;
+    for(int n=0;n<10;n++)pixels.setPixelColor(n, pixels.Color(r, g, b));     
+    pixels.show();  
+  #endif
+}
+
+void loop(void)
+{
+}

examples/Fire/M5StackFire_MicrophoneSignalTFT/M5StackFire_MicrophoneSignalTFT.ino

@@ -1,6 +1,6 @@
 /************************************************************************
 
-  M5StackFire Discovery simple oscilloscope example
+  M5StackFire simple oscilloscope example
 
   The oscilloscope has a auto trigger function to achive a stable
   visual impression when a repeating signal like a sine wave is applied.
@@ -14,10 +14,11 @@
 #include <M5Stack.h>
 
 #define M5STACKFIRE_MICROPHONE_PIN 34
+#define M5STACKFIRE_SPEAKER_PIN 25 // speaker DAC, only 8 Bit
 
 #define HORIZONTAL_RESOLUTION 320
 #define VERTICAL_RESOLUTION   240
-#define POSITION_OFFSET_Y      30
+#define POSITION_OFFSET_Y      20
 #define SIGNAL_LENGTH HORIZONTAL_RESOLUTION
 
 uint16_t oldSignal[SIGNAL_LENGTH];
@@ -28,6 +29,7 @@ uint16_t adcBuffer[SIGNAL_LENGTH];
 
 void setup()
 {
+  dacWrite(M5STACKFIRE_SPEAKER_PIN, 0); // make sure that the speaker is quite
   M5.Lcd.begin();
   M5.Lcd.fillScreen( BLACK );
   M5.Lcd.fillRect(10, 1, 150, 160, BLACK);
@@ -77,30 +79,29 @@ void showSignal()
 
   int oldx;
   int oldy;
-  int y;
+  int oldSig;
+  int x, y;
 
-  for (n = 1; n < SIGNAL_LENGTH; n++)
+  for (n = 0; n < SIGNAL_LENGTH; n++)
   {
-    y = VERTICAL_RESOLUTION - adcBuffer[n] * ( VERTICAL_RESOLUTION - POSITION_OFFSET_Y) / 4096 - POSITION_OFFSET_Y / 2  ;
+    x = n;
+    y = map(adcBuffer[n], 0, 4096, VERTICAL_RESOLUTION, POSITION_OFFSET_Y);
 
-    if (n == 1)
-    {
-      oldx = n;
-      oldy = y;
-    }
-
-    if (n < SIGNAL_LENGTH - 1)
+    if (n > 0)
     {
       // delete old line element
-      M5.Lcd.drawLine(n - 1 , oldSignal[n - 1], n, oldSignal[n], BLACK );
+      M5.Lcd.drawLine(oldx , oldSig, x, oldSignal[n], BLACK );
 
       // draw new line element
-      M5.Lcd.drawLine(oldx,               oldy, n,            y, GREEN );
+      if (n < SIGNAL_LENGTH - 1) // don't draw last element because it would generate artifacts
+      {
+        M5.Lcd.drawLine(oldx,    oldy, x,            y, GREEN );
+      }
     }
-
-    oldSignal[n - 1] = oldy;
-    oldx = n;
+    oldx = x;
     oldy = y;
+    oldSig = oldSignal[n];
+    oldSignal[n] = y;
   }
 }
 
@@ -112,7 +113,7 @@ void loop(void)
   waitForAutoTrigger();
 
   // record signal
-  for (n = 1; n < SIGNAL_LENGTH; n++)
+  for (n = 0; n < SIGNAL_LENGTH; n++)
   {
     adcBuffer[n] = analogRead( ANALOG_SIGNAL_INPUT );