Merge pull request #3107 from FoamyGuy/neopot

NeoPot example code

Author: FoamyGuy

Adafruit_NeoPot/Arduino_Rainbow_Pot/.feather_rp2040.test.only

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+// SPDX-FileCopyrightText: 2025 Tim Cocks for Adafruit Industries
+//
+// SPDX-License-Identifier: MIT
+
+#include <Adafruit_NeoPixel.h>
+int sensorPin = A0;   // select the input pin for the potentiometer
+int neoPixelPin = D4;      // select the pin for the LED
+int sensorValue = 0;  // variable to store the value coming from the sensor
+
+int readings[10];
+size_t count = 0;
+
+//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
+//   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
+//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)
+Adafruit_NeoPixel strip = Adafruit_NeoPixel(1, neoPixelPin, NEO_GRB + NEO_KHZ800);
+
+// Insert an int value at index 0 of an int array, shifting all other elements up.
+// If the array already contains 'maxCount' elements, the last one is dropped.
+// 'count' is the number of valid elements currently stored in the array.
+void insert(int arr[], size_t maxCount, int value, size_t &count){
+    // Determine how many elements we need to shift (cannot exceed the array bounds)
+    size_t shiftCount = (count < maxCount) ? count : maxCount - 1;
+
+    // Shift elements up by one position
+    for (size_t i = shiftCount; i > 0; --i) {
+        arr[i] = arr[i - 1];
+    }
+
+    // Insert the new value at the beginning
+    arr[0] = value;
+
+    // Update the element count
+    if (count < maxCount) {
+        ++count;          // we added a new element
+    } // else count stays the same – the last element was overwritten
+}
+
+// Input an array of 10 or fewer int's, and a count of how many have values
+// Returns average of the values in the array.
+int average(int arr[], size_t count){
+  int sum = 0;
+  for(int i = 0; i < 10; i++){
+    sum = sum + arr[i];
+  }
+  return sum / count;
+}
+
+// Input a value 0 to 255 to get a color value.
+// The colours are a transition r - g - b - back to r.
+uint32_t Wheel(byte WheelPos) {
+  WheelPos = 255 - WheelPos;
+  if(WheelPos < 85) {
+    return strip.Color(255 - WheelPos * 3, 0, WheelPos * 3);
+  }
+  if(WheelPos < 170) {
+    WheelPos -= 85;
+    return strip.Color(0, WheelPos * 3, 255 - WheelPos * 3);
+  }
+  WheelPos -= 170;
+  return strip.Color(WheelPos * 3, 255 - WheelPos * 3, 0);
+}
+
+void setup() {
+  Serial.begin(115200);
+  strip.begin();
+}
+
+void loop() {
+  sensorValue = analogRead(sensorPin);
+  insert(readings, 10, sensorValue, count);
+  strip.setPixelColor(0, Wheel(average(readings, count) / 4));
+  strip.show();
+}

Adafruit_NeoPot/Arduino_Rainbow_Pot/Arduino_Rainbow_Pot.ino

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+# SPDX-FileCopyrightText: 2025 Tim Cocks for Adafruit Industries
+# SPDX-License-Identifier: MIT
+"""
+NeoPot NeoPixel Rainbow Demo
+"""
+
+import board
+import analogio
+import neopixel
+import rainbowio
+
+analog_pin = analogio.AnalogIn(board.A0)
+knob_pixel = neopixel.NeoPixel(board.D4, 1, brightness=0.75, auto_write=True)
+
+analog_smoothing_buffer = []
+
+
+def map_range(x, in_min, in_max, out_min, out_max):
+    return (x - in_min) / (in_max - in_min) * out_max - out_min
+
+
+def average(values):
+    if not values:
+        return 0
+
+    return sum(values) / len(values)
+
+
+while True:
+    analog_smoothing_buffer.insert(0, analog_pin.value)
+    if len(analog_smoothing_buffer) >= 10:
+        analog_smoothing_buffer.pop(-1)
+
+    knob_pixel[0] = rainbowio.colorwheel(
+        map_range(average(analog_smoothing_buffer), 0, 65525, 0, 255)
+    )