Merge pull request #72 from taartspi/next_work7

update NeoPixel.  Use Pi4 specific SPI baud. No longer modify /boot/c…

Author: taartspi

src/main/java/com/pi4j/devices/neopixel94v/NeoPixel94V.java

@@ -39,6 +39,7 @@
 
 import com.pi4j.context.Context;
 import com.pi4j.io.spi.Spi;
+import com.pi4j.io.spi.SpiBus;
 import com.pi4j.io.spi.SpiConfig;
 import com.pi4j.io.spi.SpiMode;
 import com.pi4j.util.Console;
@@ -89,6 +90,12 @@ public class NeoPixel94V extends Component {
      * Default frequency of a WS2812 Neopixel Strip
      */
     private final int frequency = 6400000;
+    /**
+     * Default frequency of a WS2812 Neopixel Strip
+     */
+    private static final int DEFAULT_FREQUENCY_PI3 = 800_000;   //use this for a Pi4
+    private static final int DEFAULT_FREQUENCY_PI4 = 500_000;   //use this for a Pi4
+
     /**
      * between each rendering of the strip, there has to be a reset-time where nothing is written to the SPI
      */
@@ -184,9 +191,10 @@ private SpiConfig buildSpiConfig(Context pi4j, int channel, int frequency) {
         return Spi.newConfigBuilder(pi4j)
                 .id("SPI" + 1)
                 .name("LED Matrix")
+                .bus(SpiBus.BUS_0)
                 .address(channel)
                 .mode(SpiMode.MODE_0)
-                .baud(frequency) //     bit-banging from Bit to SPI-Byte
+                .baud(8 * DEFAULT_FREQUENCY_PI4) //     bit-banging from Bit to SPI-Byte
                 .provider("pigpio-spi")
                 .build();
 
@@ -369,16 +377,17 @@ public void setBrightness(double brightness) {
     /**
      * Helper Class specific for only LEDStrips and matrices
      * can calculate different colors, and gets the individual color channels
+     * G R B
      */
     public class PixelColor {
         public static final int WHITE = 0xFFFFFF;
         public static final int RED = 0x00FF00;
-        public static final int ORANGE = 0xFFC800;
+        public static final int ORANGE = 0x66CC00;
         public static final int YELLOW = 0xFFFF00;
         public static final int GREEN = 0xFF0000;
         public static final int LIGHT_BLUE = 0xadd8e6;
         public static final int BLUE = 0x0000FF;
-        public static final int PURPLE = 0x800080;
+        public static final int PURPLE = 0x008080;
         public static final int PINK = 0xFFC0CB;
         public static final int Color_COMPONENT_MAX = 0xff;
         private static final int WHITE_MASK = 0xffffff;

src/main/java/com/pi4j/devices/neopixel94v/README.md

@@ -34,7 +34,7 @@
 
 # NeoPixel94V GRB Stick
 
-
+## Wiring:  As coded this program uses SPI_0
 
 1. mvn clean package
 2. cd target/distribution
@@ -43,19 +43,14 @@ Parm -t   traceLevel
 
 # NOTE: 
 At present this code uses the SPI.
+The timing is calculated for the Pi4 hardware.
+
 NEOPIXEL WS2812B uses the following timing to represent a '1' or a '0' bit. To
 accomplish in SPI, a '1' sends a byte0b11111000 and a '0' sends a byte 0b11000000.
 When the array of bytes are sent via SPI at a specific frequency the WS2812B 
 interprets the bytes as correctly timed 0's and 1's.
-To accomplish the SPI frequency is set to 6400000.  This frequency will vary
-dependent upon the PI throttling.  To lock the frequency to the desired value:
-
-PI4 : Add the following to  /boot/config.txt
-core_freq=250
-core_freq_min=250
+To accomplish the SPI frequency is set to 8*500_000.
 
-Similar changes for previous model PIs are not supplied. Also, no 
-performance testing was performed to determine possible impacts
 
 Pulse duration to represent a one or a zero.
 int32_t highTime0NanoSeconds,    400 ns