Should now adhere to system level configuration changes.

Pi4J · Sep 16, 2024 · 738a493 · 738a493
1 parent 20d71f2
commit 738a493
Showing 1 changed file with 16 additions and 3 deletions.
diff --git a/...ries/pi4j-library-pigpio/src/main/java/com/pi4j/library/pigpio/impl/PiGpioNativeImpl.java b/...ries/pi4j-library-pigpio/src/main/java/com/pi4j/library/pigpio/impl/PiGpioNativeImpl.java
@@ -33,8 +33,10 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.io.File;
 import java.util.Arrays;
 import java.util.Objects;
+import java.util.Scanner;
 
 import static com.pi4j.library.pigpio.PiGpioConst.PI_IF_DISABLE_FIFO;
 import static com.pi4j.library.pigpio.PiGpioConst.PI_IF_DISABLE_SOCK;
@@ -49,6 +51,8 @@
 public class PiGpioNativeImpl extends PiGpioBase implements PiGpio {
     protected Logger logger = LoggerFactory.getLogger(this.getClass());
 
+    private int SPI_BUFFSIZ = 4096;
+
     private static final PiGpioNativeImpl instance;
     static {
         instance = new PiGpioNativeImpl();
@@ -105,6 +109,16 @@ public int gpioInitialise() {
             result = PIGPIO.gpioInitialise();
             validateResult(result);
 
+            try {
+                Scanner scanner = new Scanner(new File("/sys/module/spidev/parameters/bufsiz"));
+                if (scanner.hasNextInt()) {
+                    SPI_BUFFSIZ = scanner.nextInt();
+                }
+                logger.trace("[INITIALIZE] -> SPI_BUFFSIZ={}", SPI_BUFFSIZ);
+            } catch (Exception e) {
+                logger.error(e.getMessage(), e);
+            }
+
             // initialization successful
             this.initialized = true;
             logger.debug("[INITIALIZE] -- INITIALIZED SUCCESSFULLY");
@@ -1456,14 +1470,13 @@ public int spiWrite(int handle, byte[] data, int offset, int length) {
         // write data array to SPI bus/channel
         int result = 0;
         byte[] someData = Arrays.copyOfRange(data, offset, length);
-        int chunksize = 4096;
         int start = 0;
         while (start < someData.length) {
-            int end = Math.min(someData.length, start + chunksize);
+            int end = Math.min(someData.length, start + SPI_BUFFSIZ);
             byte[] chunk = Arrays.copyOfRange(someData, start, end);
             result += PIGPIO.spiWrite(handle, chunk, 0, chunk.length );
             logger.trace("[SPI::WRITE] <- HANDLE={}; SUCCESS={}", handle, (result>=0));
-            start += chunksize;
+            start += SPI_BUFFSIZ;
         }
         validateResult(result, false);
         return result;