Merge pull request #384 from mores/ISSUE-383

Utilize SPI Buffer size for large writes
Pi4J · Sep 17, 2024 · db6a10a · db6a10a
2 parents 98fecbc + 738a493
commit db6a10a
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Showing 2 changed files with 27 additions and 5 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");
@@ -1454,8 +1468,16 @@ public int spiWrite(int handle, byte[] data, int offset, int length) {
         Objects.checkFromIndexSize(offset, length, data.length);
         validateHandle(handle);
         // write data array to SPI bus/channel
-        int result = PIGPIO.spiWrite(handle, data, offset, length);
-        logger.trace("[SPI::WRITE] <- HANDLE={}; SUCCESS={}", handle, (result>=0));
+        int result = 0;
+        byte[] someData = Arrays.copyOfRange(data, offset, length);
+        int start = 0;
+        while (start < someData.length) {
+            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 += SPI_BUFFSIZ;
+        }
         validateResult(result, false);
         return result;
     }

diff --git a/pom.xml b/pom.xml
@@ -274,10 +274,10 @@
         <maven-antrun-plugin.version>3.1.0</maven-antrun-plugin.version>
         <maven-assembly-plugin.version>3.3.0</maven-assembly-plugin.version>
         <maven-bundle-plugin.version>5.1.2</maven-bundle-plugin.version>
-        <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
+        <maven-compiler-plugin.version>3.13.0</maven-compiler-plugin.version>
         <maven-dependency-plugin.version>3.1.2</maven-dependency-plugin.version>
         <maven-gpg-plugin.version>3.2.1</maven-gpg-plugin.version>
-        <maven-jar-plugin.version>3.2.0</maven-jar-plugin.version>
+        <maven-jar-plugin.version>3.4.2</maven-jar-plugin.version>
         <maven-javadoc-plugin.version>3.2.0</maven-javadoc-plugin.version>
         <maven-release-plugin.version>3.0.0-M4</maven-release-plugin.version>
         <maven-resource-plugin.version>3.2.0</maven-resource-plugin.version>
@@ -668,7 +668,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-enforcer-plugin</artifactId>
-                    <version>3.0.0-M2</version>
+                    <version>3.5.0</version>
                 </plugin>
 
                 <!-- Deploy to Maven plugin -->