Add I/O and scheduler

neopixel_test.txt

+// Simple NeoPixel test.  Lights just a few pixels at a time so a
+// 1m strip can safely be powered from Arduino 5V pin.  Arduino
+// may nonetheless hiccup when LEDs are first connected and not
+// accept code.  So upload code first, unplug USB, connect pixels
+// to GND FIRST, then +5V and digital pin 6, then re-plug USB.
+// A working strip will show a few pixels moving down the line,
+// cycling between red, green and blue.  If you get no response,
+// might be connected to wrong end of strip (the end wires, if
+// any, are no indication -- look instead for the data direction
+// arrows printed on the strip).
+
+#include <Arduino.h>
+#include <Adafruit_NeoPixel.h>
+
+#define PIN      6
+#define N_LEDS 144
+
+Adafruit_NeoPixel strip = Adafruit_NeoPixel(N_LEDS, PIN, NEO_GRB + NEO_KHZ800);
+
+void setup() {
+  strip.begin();
+}
+
+static void chase(uint32_t c) {
+  for(uint16_t i=0; i<strip.numPixels()+4; i++) {
+      strip.setPixelColor(i  , c); // Draw new pixel
+      strip.setPixelColor(i-4, 0); // Erase pixel a few steps back
+      strip.show();
+      delay(25);
+  }
+}
+
+void loop() {
+  chase(strip.Color(255, 0, 0)); // Red
+  chase(strip.Color(0, 255, 0)); // Green
+  chase(strip.Color(0, 0, 255)); // Blue
+}
\ No newline at end of file

platformio.ini

@@ -15,5 +15,6 @@ framework = arduino
 
 lib_deps =
   Adafruit NeoPixel
+  TaskScheduler
 
 upload_port = /dev/cu.wchusbserial1420

src/main.cpp

 #include <Arduino.h>
 #include <Adafruit_NeoPixel.h>
+#include <TaskScheduler.h>
 
 #define NEOPIXEL_PIN 6
 #define NEOPIXEL_LEN 105
 
+// Pin A and Pin B are connected if the button is pressed.
+// Pin A and Pin No are connected if no external button is connected.
+#define EXTERNAL_BUTTON_PIN_A 7
+#define EXTERNAL_BUTTON_PIN_B 9
+#define EXTERNAL_BUTTON_PIN_NO 8
+
+#define INTERNAL_BUTTON_PIN_A 10
+#define INTERNAL_BUTTON_PIN_B 11
+
 Adafruit_NeoPixel pixels(NEOPIXEL_LEN, NEOPIXEL_PIN, NEO_GRB + NEO_KHZ800);
 
+Scheduler scheduler;
+void handleButton();
+Task taskButton(TASK_IMMEDIATE, TASK_FOREVER, &handleButton);
+void handleStep();
+Task taskStep(25, TASK_FOREVER, &handleStep);
+
 void setup() {
   pinMode(LED_BUILTIN, OUTPUT);
+
+  pinMode(EXTERNAL_BUTTON_PIN_A, OUTPUT);
+  digitalWrite(EXTERNAL_BUTTON_PIN_A, LOW);
+  pinMode(EXTERNAL_BUTTON_PIN_B, INPUT_PULLUP);
+  pinMode(EXTERNAL_BUTTON_PIN_NO, INPUT_PULLUP);
+  pinMode(INTERNAL_BUTTON_PIN_A, OUTPUT);
+  digitalWrite(INTERNAL_BUTTON_PIN_A, LOW);
+  pinMode(INTERNAL_BUTTON_PIN_B, INPUT_PULLUP);
+
   pixels.begin();
+  scheduler.init();
+  scheduler.addTask(taskButton);
+  taskButton.enable();
+  scheduler.addTask(taskStep);
+  taskStep.enable();
 }
 
-int pos = 0;
-
 void loop() {
+  scheduler.execute();
+}
+
+uint32_t color = 0xFFFFFF;
+int position = 0;
+
+void show() {
   for (int i = 0; i < NEOPIXEL_LEN; i++) {
-    pixels.setPixelColor(i, 0xFFFFFF);
+    pixels.setPixelColor(i, 0);
+  }
+  for (int i = position; i < position + 10; i++) {
+    pixels.setPixelColor(i, color);
   }
-  pixels.setPixelColor(pos, 0xFF0000);
   pixels.show();
-  pos = (pos + 1) % NEOPIXEL_LEN;
+}
 
-  digitalWrite(LED_BUILTIN, HIGH);
-  delay(500);
-  digitalWrite(LED_BUILTIN, LOW);
-  delay(500);
+void handleButton() {
+  if (digitalRead(INTERNAL_BUTTON_PIN_B) == LOW) {
+    color = 0x0000FF;
+  } else if (digitalRead(EXTERNAL_BUTTON_PIN_NO) == LOW) {
+    color = 0xFF0000;
+  } else if (digitalRead(EXTERNAL_BUTTON_PIN_B) == LOW) {
+    color = 0x00FF00;
+  }
+  show();
+}
+
+boolean forward = true;
+void handleStep() {
+  if (forward) {
+    position = position + 1;
+    if (position > NEOPIXEL_LEN - 11) {
+      position = position - 2;
+      forward = false;
+    }
+  } else {
+    position = position - 1;
+    if (position < 0) {
+      position = 1;
+      forward = true;
+    }
+  }
 }