Added ADC support (#13)

CMakeLists.txt

@@ -18,7 +18,7 @@ if (${TARGET} STREQUAL PICO)
     include(pico_sdk_import.cmake)
 endif()
 
-project(pjvm VERSION 0.0.2)
+project(pjvm VERSION 0.0.4)
 
 include(CTest) 
 
@@ -49,14 +49,10 @@ if (${TARGET} STREQUAL LINUX)
     set(PJVM_SOURCES src/linux/Main.cpp src/linux/OS.cpp)
 endif()
 
-#add_library(libjvm STATIC IMPORTED)
-#set_property(TARGET libjvm PROPERTY IMPORTED_LOCATION ${BINARY_DIR}/libjvm.a)
-#add_dependencies(jvmprojlib jvmproj)
-
 add_executable(pjvm ${PJVM_SOURCES})
 
 if (${TARGET} STREQUAL PICO)
-    set(PJVM_INCLUDE_OS_DIRS lib/src/vm/os/pico)
+    set(PJVM_INCLUDE_OS_DIRS lib/src/vm/os/pico ${PICO_SDK_PATH}/src/rp2_common/hardware_adc/include)
 endif()
 if (${TARGET} STREQUAL LINUX)
     set(PJVM_INCLUDE_OS_DIRS lib/src/vm/os/linux)
@@ -87,7 +83,7 @@ target_link_directories(pjvm PRIVATE ${CMAKE_BINARY_DIR})
 
 if (${TARGET} STREQUAL PICO)
     # Add pico_stdlib library which aggregates commonly used features
-    target_link_libraries(pjvm pico_stdlib)
+    target_link_libraries(pjvm pico_stdlib hardware_adc)
     # create map/bin/hex/uf2 file in addition to ELF.
     pico_add_extra_outputs(pjvm)
     pico_enable_stdio_usb(pjvm 1)

examples/adc/build.xml

@@ -0,0 +1,56 @@
+<!--
+
+SPDX-License-Identifier: GPL-2.0-or-later
+Copyright (C) 2024 Oren Sokoler (https://github.com/orenskl)
+
+-->
+
+<project name="adc" basedir="." default="bin">
+
+    <property environment="env"/>
+    <fail unless="env.JAVA_PICO_HOME" message="Please set JAVA_PICO_HOME to the location of the pjvm base directory"/>
+    <property name="pjvm.dir" value="${env.JAVA_PICO_HOME}"/>
+
+    <property name="src.dir"     value="src"/>
+    <property name="build.dir"   value="build"/>
+    <property name="classes.dir" value="${build.dir}/classes"/>
+    <property name="jar.dir"     value="${build.dir}/jar"/>
+    <property name="main-class"  value="Main"/>
+
+    <target name="clean">
+        <delete dir="${build.dir}"/>
+    </target>
+
+    <target name="compile">
+        <mkdir dir="${classes.dir}"/>
+        <javac target="1.4" source="1.4" srcdir="${src.dir}" destdir="${classes.dir}" 
+               bootclasspath="${pjvm.dir}/lib/classes.jar" includeantruntime="false"/>
+    </target>
+
+    <target name="preverify" depends="compile">
+        <echo message="Preverifying classes"/>
+        <exec executable="${pjvm.dir}/bin/preverify">
+            <arg value="-d"/>
+            <arg value="${classes.dir}.preverify"/>
+            <arg value="-classpath"/>
+            <arg value="${pjvm.dir}/lib/classes.jar"/>
+            <arg value="${classes.dir}"/>
+        </exec>
+    </target>
+
+    <target name="jar" depends="preverify">
+        <mkdir dir="${jar.dir}"/>
+        <jar destfile="${jar.dir}/${ant.project.name}.jar" basedir="${classes.dir}.preverify" compress="false" />
+    </target>
+
+    <target name="bin" depends="jar">
+        <echo message="Wrapping JAR"/>
+        <exec executable="${pjvm.dir}/bin/wrapjar.sh">
+            <arg value="${jar.dir}/${ant.project.name}.jar"/>
+            <arg value="${jar.dir}/${ant.project.name}.jar.bin"/>
+        </exec>
+    </target>
+
+    <target name="clean-build" depends="clean,bin"/>
+
+</project>

examples/adc/src/Main.java

@@ -0,0 +1,29 @@
+/*
+ * 
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2024 Oren Sokoler (https://github.com/orenskl)
+ * 
+ */
+
+import pico.hardware.ADCChannel;
+
+class Main {
+
+    /* A simple ADC test */
+    private static final int ADC_CHANNEL = 2;
+
+    public static void main(String[] args) {
+        System.out.println("ADC example");
+        ADCChannel a = new ADCChannel(ADC_CHANNEL);
+        while (true) {
+            int value = a.read();
+            System.out.println("ADC Channel " + ADC_CHANNEL + " value is " + value);
+            try {
+                Thread.sleep(500);
+            } catch (Exception e) {
+                System.out.println(e.getMessage());
+            }
+        }
+    }
+
+}

lib/CMakeLists.txt

@@ -25,7 +25,9 @@ if (${TARGET} STREQUAL PICO)
     set(CMAKE_CXX_COMPILER arm-none-eabi-g++)
 endif()
 if (${TARGET} STREQUAL PICO)
-    set(JVM_DEVICE_CLASSES ${CMAKE_SOURCE_DIR}/src/javaapi/device/pico/hardware/GPIOPin.java)
+    set(JVM_DEVICE_CLASSES ${CMAKE_SOURCE_DIR}/src/javaapi/device/pico/hardware/GPIOPin.java
+                           ${CMAKE_SOURCE_DIR}/src/javaapi/device/pico/hardware/ADCChannel.java
+    )
 endif()
 
 set(JVM_CLASSES 
@@ -135,6 +137,7 @@ set(JVM_CLASSES
 
 add_custom_command(OUTPUT ROMImage.cpp
                    DEPENDS ${JVM_CLASSES} ${BINARY_DIR}/romgen
+                   COMMAND rm ARGS -rf ${CMAKE_BINARY_DIR}/classes ${CMAKE_BINARY_DIR}/classes.preverify
                    COMMAND mkdir ARGS -p ${CMAKE_BINARY_DIR}/classes
                    COMMAND javac ARGS -source 1.4 -target 1.4 -d ${CMAKE_BINARY_DIR}/classes -bootclasspath ${CMAKE_BINARY_DIR}/classes ${JVM_CLASSES}
                    COMMAND ${CMAKE_SOURCE_DIR}/tools/preverify/bin/preverify ARGS -d ${CMAKE_BINARY_DIR}/classes.preverify ${CMAKE_BINARY_DIR}/classes

lib/src/javaapi/device/pico/hardware/ADCChannel.java

@@ -0,0 +1,53 @@
+/*
+ * 
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright (C) 2024 Oren Sokoler (https://github.com/orenskl)
+ * 
+ */
+
+ package pico.hardware;
+
+ /**
+  * A <code>ADCChannel</code> class represents a single Analog To Digital
+  * conversion channel, the channel number is hardware specific and is not 
+  * decoded or encoded in anyway, it is passed to the hardware level as is. 
+  * The values that are read from the ADC are integers and are the direct 
+  * read of the ADC, e.g. if the ADC is a 12 bit ADC then the values you 
+  * could get are from 0 to 4095.
+  */
+
+public class ADCChannel {
+
+    /**
+     * The ADC channel number
+     */
+    private int channel;
+
+    /**
+     * 
+     * Constructor for a single ADC channel
+     * 
+     * @param channel The channel number
+     * 
+     */
+    public ADCChannel ( int channel ) {
+        this.channel = channel;
+        adc_init(channel);
+    }
+
+    /**
+     * Perform a single conversion and read its value from the ADC channel
+     * 
+     * @return the ADC channel digital value
+     */
+    public int read () {
+        return adc_read(this.channel);
+    }
+
+    /*
+     * Natives for the device hardware
+     */
+    private static native void adc_init ( int channel );
+    private static native int  adc_read ( int channel );
+
+}

src/pico/Main.cpp

@@ -17,6 +17,7 @@
 #include "sni.h"
 
 #include "pico/stdlib.h"
+#include "hardware/adc.h"
 
 #include <stdio.h>
 #include <stdlib.h>
@@ -87,6 +88,8 @@ int main( void )
   stdio_usb_init();
   /* We have to wait for the USB stack */
   sleep_ms(3000);
+  /* Initialize the ADC hardware */
+  adc_init();
 
   // Call this before any other Jvm_ functions.
   JVM_Initialize();

src/pico/Natives.cpp

@@ -10,13 +10,17 @@
 #include "kni.h"
 
 #include "hardware/gpio.h"
+#include "hardware/adc.h"
+
+#define         ADC_GPIO_PIN_MIN        26
+#define         ADC_GPIO_PIN_MAX        29
 
 extern "C" {
 
 /*
  * This file is the native implementation of the device specific
  * classes that access the hardware, these functions are called from
- * the Java classes. All the functions are void but they get thei
+ * the Java classes. All the functions are void but they get their
  * input parameters from the JVM stack via KNI calls
  */
 
@@ -80,4 +84,30 @@ int Java_pico_hardware_GPIOPin_gpio_1get( void )
     return gpio_get(pinNumber);
 }
 
-}
+/**
+ * Initialize an ADC channel
+@ * 
+ * @param The 1st parameter is the channel number
+ * 
+ */
+void Java_pico_hardware_ADCChannel_adc_1init ( void )
+{
+    int channel = KNI_GetParameterAsInt(1);
+    adc_gpio_init(ADC_GPIO_PIN_MIN + channel);
+}
+
+/**
+ * Read a single sample from the ADC channel
+ * 
+ * @param The 1st parameter is the channel number
+ * @return The sample read as an integer
+ * 
+ */
+int Java_pico_hardware_ADCChannel_adc_1read ( void ) 
+{
+    int channel = KNI_GetParameterAsInt(1);
+    adc_select_input(channel);
+    return adc_read();
+}
+
+} /* extern "C" */