add remote gpio control as an example plugin

https://github.com/meshtastic/Meshtastic-device/issues/182

src/mesh/portnums.pb.h

@@ -17,7 +17,7 @@ extern "C" {
 typedef enum _PortNum {
     PortNum_UNKNOWN_APP = 0,
     PortNum_TEXT_MESSAGE_APP = 1,
-    PortNum_GPIO_APP = 2,
+    PortNum_REMOTE_HARDWARE_APP = 2,
     PortNum_POSITION_APP = 3,
     PortNum_NODEINFO_APP = 4,
     PortNum_PRIVATE_APP = 256,

src/mesh/remote_hardware.pb.c

@@ -0,0 +1,13 @@
+/* Automatically generated nanopb constant definitions */
+/* Generated by nanopb-0.4.1 */
+
+#include "remote_hardware.pb.h"
+#if PB_PROTO_HEADER_VERSION != 40
+#error Regenerate this file with the current version of nanopb generator.
+#endif
+
+PB_BIND(HardwareMessage, HardwareMessage, AUTO)
+
+
+
+

src/mesh/remote_hardware.pb.h

@@ -0,0 +1,69 @@
+/* Automatically generated nanopb header */
+/* Generated by nanopb-0.4.1 */
+
+#ifndef PB_REMOTE_HARDWARE_PB_H_INCLUDED
+#define PB_REMOTE_HARDWARE_PB_H_INCLUDED
+#include <pb.h>
+
+#if PB_PROTO_HEADER_VERSION != 40
+#error Regenerate this file with the current version of nanopb generator.
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Enum definitions */
+typedef enum _HardwareMessage_MessageType {
+    HardwareMessage_MessageType_UNSET = 0,
+    HardwareMessage_MessageType_WRITE_GPIOS = 1,
+    HardwareMessage_MessageType_WATCH_GPIOS = 2,
+    HardwareMessage_MessageType_GPIOS_CHANGED = 3,
+    HardwareMessage_MessageType_READ_GPIOS = 4,
+    HardwareMessage_MessageType_READ_GPIOS_REPLY = 5
+} HardwareMessage_MessageType;
+
+/* Struct definitions */
+typedef struct _HardwareMessage {
+    HardwareMessage_MessageType typ;
+    uint64_t gpio_mask;
+    uint64_t gpio_value;
+} HardwareMessage;
+
+
+/* Helper constants for enums */
+#define _HardwareMessage_MessageType_MIN HardwareMessage_MessageType_UNSET
+#define _HardwareMessage_MessageType_MAX HardwareMessage_MessageType_READ_GPIOS_REPLY
+#define _HardwareMessage_MessageType_ARRAYSIZE ((HardwareMessage_MessageType)(HardwareMessage_MessageType_READ_GPIOS_REPLY+1))
+
+
+/* Initializer values for message structs */
+#define HardwareMessage_init_default             {_HardwareMessage_MessageType_MIN, 0, 0}
+#define HardwareMessage_init_zero                {_HardwareMessage_MessageType_MIN, 0, 0}
+
+/* Field tags (for use in manual encoding/decoding) */
+#define HardwareMessage_typ_tag                  1
+#define HardwareMessage_gpio_mask_tag            2
+#define HardwareMessage_gpio_value_tag           3
+
+/* Struct field encoding specification for nanopb */
+#define HardwareMessage_FIELDLIST(X, a) \
+X(a, STATIC,   SINGULAR, UENUM,    typ,               1) \
+X(a, STATIC,   SINGULAR, UINT64,   gpio_mask,         2) \
+X(a, STATIC,   SINGULAR, UINT64,   gpio_value,        3)
+#define HardwareMessage_CALLBACK NULL
+#define HardwareMessage_DEFAULT NULL
+
+extern const pb_msgdesc_t HardwareMessage_msg;
+
+/* Defines for backwards compatibility with code written before nanopb-0.4.0 */
+#define HardwareMessage_fields &HardwareMessage_msg
+
+/* Maximum encoded size of messages (where known) */
+#define HardwareMessage_size                     24
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+#endif

src/plugins/RemoteHardwarePlugin.cpp

@@ -0,0 +1,17 @@
+#include "RemoteHardwarePlugin.h"
+#include "MeshService.h"
+#include "NodeDB.h"
+#include "RTC.h"
+#include "Router.h"
+#include "configuration.h"
+#include "main.h"
+
+RemoteHardwarePlugin remoteHardwarePlugin;
+
+bool RemoteHardwarePlugin::handleReceivedProtobuf(const MeshPacket &mp, const HardwareMessage &p)
+{
+
+    return false; // Let others look at this message also if they want
+}
+
+

src/plugins/RemoteHardwarePlugin.h

@@ -0,0 +1,24 @@
+#pragma once
+#include "ProtobufPlugin.h"
+#include "remote_hardware.pb.h"
+
+/**
+ * A plugin that provides easy low-level remote access to device hardware.
+ */
+class RemoteHardwarePlugin : public ProtobufPlugin<HardwareMessage>
+{
+  public:
+    /** Constructor
+     * name is for debugging output
+     */
+    RemoteHardwarePlugin() : ProtobufPlugin("remotehardware", PortNum_REMOTE_HARDWARE_APP, HardwareMessage_fields) {}
+
+  protected:
+    /** Called to handle a particular incoming message
+
+    @return true if you've guaranteed you've handled this message and no other handlers should be considered for it
+    */
+    virtual bool handleReceivedProtobuf(const MeshPacket &mp, const HardwareMessage &p);
+};
+
+extern RemoteHardwarePlugin remoteHardwarePlugin;