code cleanups, switch LEDs to black when no serial connection

teensy_cvgate_mcp4725_neopixel/teensy_cvgate_mcp4725_neopixel.ino

@@ -19,40 +19,39 @@
 
 #include "colormap.h"
 
-#define enable1 true
-#define enable2 true
+#define NEOPIXEL_PIN 14
+#define GATE1_PIN    15
+#define GATE2_PIN    16
+#define WIRE_SDAPIN  18
+#define WIRE_SCLPIN  19
 
 // 0x60 is the I2C Address of the MCP4725, by default (A0 pulled to GND).
 // Please note that this breakout is for the MCP4725A0.
 // For devices with A0 pulled HIGH, use 0x61
 #define address1 0x60
 #define address2 0x61
 
-#define gate1pin A0      // the pin controlling the digital gate
-#define gate2pin A1      // the pin controlling the digital gate
-
 #define MCP4726_CMD_WRITEDAC            (0x40)  // Writes data to the DAC
 #define MCP4726_CMD_WRITEDACEEPROM      (0x60)  // Writes data to the DAC and the EEPROM (persisting the assigned value after reset)
 
 // the values of the DAC range from 0 to 4095 (12 bits)
 #define MAXVALUE  4095.
 
-// these are the commands over the serial interface
+// these are used to interpret the commands over the serial interface
 #define NONE      0
 #define VOLTAGE   1
 #define GATE      2
 
-// status after parsing the commands
-#define OK     0
-#define ERROR -1
+// this is the status after parsing the commands over the serial interface
+#define OK       0
+#define ERROR   -1
 
-#define PIXELPIN 20
 #define NUMPIXELS 4
 #define BRIGHTNESS 0.3
 
-Adafruit_NeoPixel pixels(NUMPIXELS, PIXELPIN, NEO_GRB + NEO_KHZ800);
+Adafruit_NeoPixel pixels(NUMPIXELS, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);
 
-// the initial values of the output control voltages and gates
+// tghese are the initial values of the output control voltages and gates
 int voltage1 = 0, voltage2 = 0;
 int gate1 = 0, gate2 = 0;
 
@@ -92,17 +91,35 @@ void setup() {
   Serial.setTimeout(1000);
 
   Wire.begin();
+  Wire.setSDA(WIRE_SDAPIN);
+  Wire.setSCL(WIRE_SCLPIN);
 
   // initialize the gate pins as output:
-  pinMode(gate1pin, OUTPUT);
-  pinMode(gate2pin, OUTPUT);
+  pinMode(GATE1_PIN, OUTPUT);
+  pinMode(GATE2_PIN, OUTPUT);
 
   // INITIALIZE NeoPixel strip object
   pixels.begin(); 
+  delay(1000);
 
   // Set all pixel colors to 'off'
   pixels.clear(); 
-
+
+  // Set the pixels to RGBW to indicate that setup is done
+  pixels.setPixelColor(0, pixels.Color(128, 0, 0));
+  pixels.show();
+  delay(250);
+  pixels.setPixelColor(1, pixels.Color(0, 128, 0));
+  pixels.show();
+  delay(250);
+  pixels.setPixelColor(2, pixels.Color(0, 0, 128));
+  pixels.show();
+  delay(250);
+  pixels.setPixelColor(3, pixels.Color(128, 128, 128));
+  pixels.show();
+  delay(250);
+
+  Serial.println("Setup done.");
   return;
 }
 
@@ -147,11 +164,11 @@ void loop() {
       switch (channel) {
         case 1:
           voltage1 = (value > MAXVALUE ? MAXVALUE : value);
-          status = (enable1 ? OK : ERROR);
+          status = OK;
           break;
         case 2:
           voltage2 = (value > MAXVALUE ? MAXVALUE : value);
-          status = (enable2 ? OK : ERROR);
+          status = OK;
           break;
         default:
           status = ERROR;
@@ -176,27 +193,32 @@ void loop() {
       status = ERROR;
     }
     if (status == OK)
-      Serial.println("ok");
+      Serial.println("OK");
     else if (status == ERROR)
       Serial.println("error");
   }
   else {
-    // refresh the output voltages and gates
-    if (enable1) {
+    // update the output cointrol voltages and gates
       setValue(address1, voltage1);
-      digitalWrite(gate1pin, gate1);
-    }
-    if (enable2) {
       setValue(address2, voltage2);
-      digitalWrite(gate2pin, gate2);
-    }
+      digitalWrite(GATE1_PIN, gate1);
+      digitalWrite(GATE2_PIN, gate2);
+
+    // update the Neopixels by mapping a value between 0 and 1 onto the colormap
+    // note that they are mounted in the opposite order than the 3.5 mm jacks
 
-    // update the color of the Neopixels
-    // the integer representation of the control voltage is represented between 0 and 4095
-    setColor(0, voltage1/MAXVALUE);
-    setColor(1, voltage2/MAXVALUE); 
-    // the integer representation of the gate voltage is either 0 or 1
-    setColor(2, gate1); 
-    setColor(3, gate2); 
+    if (!Serial) {
+      // switch all pixels off when there is no serial connection
+      pixels.clear(); 
+      pixels.show(); 
+    }
+    else {
+      // the integer representation of the control voltage is represented between 0 and 4095
+      setColor(3, voltage1/MAXVALUE);
+      setColor(2, voltage2/MAXVALUE); 
+      // the integer representation of the gate voltage is either 0 or 1
+      setColor(1, gate1); 
+      setColor(0, gate2); 
+    }
   }
 } //main