plugin.cpp

/*
 * Fledge south plugin.
 *
 * This plugin is for the Advantech USB-4704 Portable Data Acquisition Module.
 * It supports a number of digitial and analogue inputs on that device. The mapping
 * of an input to a reading value within the JSON reading paylog is controlled
 * via the plugin configuratio category.
 *
 * In order to build this plugin the Advantech biodaq library must be installed,
 * to use it the kernel module for the USB-4704 must also be installed and
 * enabled on your machine.
 *
 * Copyright (c) 2018 Dianomic Systems
 *
 * Released under the Apache 2.0 Licence
 *
 * Author: Mark Riddoch
 */
#include <usb4704.h>
#include <plugin_api.h>
#include <stdio.h>
#include <stdlib.h>
#include <strings.h>
#include <string>
#include <logger.h>
#include <plugin_exception.h>
#include <config_category.h>
#include <rapidjson/document.h>
#include <version.h>

using namespace std;
using namespace rapidjson;

#define DEFAULT_CONNECTIONS QUOTE({				\
	"analogue_example" : {					\
		"type" : "analogue",				\
		"pin" : "AI0",					\
		"name" : "value1",				\
		"scale" : 0.1					\
	},							\
	"digital_example" : {					\
		"type" : "digital",				\
		"pins" : ["DI0", "DI1", "DI2", "DI3"],		\
		"name" : "value1",				\
		"scale" : 0.1					\
		} 						\
	})
/**
 * Default configuration
 */
static const char *default_config = QUOTE({
		"plugin" : {
			"description" : "Advantech USB-4704 Data Acquisition Module",
			"type" : "string",
		       	"default" : "usb4704",
			"readonly": "true"
			},
		"asset" : {
			"description" : "Asset name to use for readings",
			"type" : "string",
		       	"default" : "usb4704",
			 "order": "1",
			 "displayName": "Asset Name",
			 "mandatory": "true"
			 },
		"connections" : {
			"description" : "Utilisation of connections on USB-4704",
		    	"order": "2",
			"displayName": "Connections",
			"type" : "JSON",
		       	"default" : DEFAULT_CONNECTIONS
			}
});

/**
 * The USB-4704 plugin interface
 */
extern "C" {

/**
 * The plugin information structure
 */
static PLUGIN_INFORMATION info = {
	"usb4704",                // Name
	VERSION,                  // Version
	0,    			  // Flags
	PLUGIN_TYPE_SOUTH,        // Type
	"1.0.0",                  // Interface version
	default_config		  // Default configuration
};

/**
 * Return the information about this plugin
 */
PLUGIN_INFORMATION *plugin_info()
{
	return &info;
}

/**
 * Initialise the plugin, called to get the plugin handle
 */
PLUGIN_HANDLE plugin_init(ConfigCategory *config)
{
USB4704 *usb = 0;


	usb = new USB4704();

	if (config->itemExists("asset"))
	{
		usb->setAssetName(config->getValue("asset"));
	}
	else
	{
		usb->setAssetName("usb4704");
	}

	// Now process the Connections
	string connections = config->getValue("connections");
	rapidjson::Document doc;
	doc.Parse(connections.c_str());
	if (!doc.HasParseError())
	{
		for (rapidjson::Value::ConstMemberIterator itr = doc.MemberBegin();
						itr != doc.MemberEnd(); ++itr)
		{
			const char *type = itr->value["type"].GetString();
			if (strcmp(type, "analogue") == 0)
			{
				double scale = 1.0;
				if (itr->value.HasMember("scale"))
				{
					scale = itr->value["scale"].GetFloat();
				}
				if (itr->value.HasMember("pin") && itr->value["pin"].IsString())
				{
					usb->addAnalogueConnection(itr->name.GetString(), itr->value["pin"].GetString(),
							scale);
				}
				else
				{
					Logger::getLogger()->fatal("Analogue connection for USB-4704 is missing definition of pin");
					throw exception();
				}
			}
			else if (strcmp(type, "digital") == 0)
			{
				if (itr->value.HasMember("pins") && itr->value["pins"].IsArray())
				{
					vector<string> pins;
					for (Value::ConstValueIterator pitr = itr->value["pins"].Begin();
							pitr != itr->value["pins"].End(); ++pitr)
					{
						pins.push_back(string(pitr->GetString()));
					}
					usb->addDigitalConnection(itr->name.GetString(), pins);
				}
				else
				{
					Logger::getLogger()->fatal("Digital connection for USB-4704 is missing definition of pins, or pins is not an array");
				}
			}
			else
			{
				Logger::getLogger()->fatal("Configuration type must have either an analogue or digitial. Type %s is not supported", type);
				throw exception();
			}
		}
	}

	return (PLUGIN_HANDLE)usb;
}

/**
 * Start the Async handling for the plugin
 */
void plugin_start(PLUGIN_HANDLE *handle)
{
	if (!handle)
		return;
}

/**
 * Poll for a plugin reading
 */
Reading plugin_poll(PLUGIN_HANDLE *handle)
{
USB4704 *usb = (USB4704 *)handle;

	if (!handle)
		throw exception();
	return usb->takeReading();
}

/**
 * Reconfigure the plugin
 */
void plugin_reconfigure(PLUGIN_HANDLE *handle, string& newConfig)
{
ConfigCategory	config("update", newConfig);
USB4704		*usb = (USB4704 *)*handle;

	if (config.itemExists("asset"))
	{
		usb->setAssetName(config.getValue("asset"));
	}
	if (config.itemExists("connections"))
	{
		string connections = config.getValue("connections");
		rapidjson::Document doc;
		doc.Parse(connections.c_str());
		if (!doc.HasParseError())
		{
			usb->clearConnections();
			for (rapidjson::Value::ConstMemberIterator itr = doc.MemberBegin();
							itr != doc.MemberEnd(); ++itr)
			{
				const char *type = itr->value["type"].GetString();
				if (strcmp(type, "analogue") == 0)
				{
					double scale = 1.0;
					if (itr->value.HasMember("scale"))
					{
						scale = itr->value["scale"].GetFloat();
					}
					if (itr->value.HasMember("pin") && itr->value["pin"].IsString())
					{
						usb->addAnalogueConnection(itr->name.GetString(), itr->value["pin"].GetString(),
								scale);
					}
					else
					{
						Logger::getLogger()->error("Analogue connection for USB-4704 is missing definition of pin");
						throw exception();
					}
				}
				else if (strcmp(type, "digital") == 0)
				{
					if (itr->value.HasMember("pins") && itr->value["pins"].IsArray())
					{
						vector<string> pins;
						for (Value::ConstValueIterator pitr = itr->value.Begin();
									pitr != itr->value.End(); ++pitr)
						{
							pins.push_back(string(pitr->GetString()));
						}
						usb->addDigitalConnection(itr->name.GetString(), pins);
					}
				}
				else
				{
					throw exception();
				}
			}
		}
	}
}

/**
 * Shutdown the plugin
 */
void plugin_shutdown(PLUGIN_HANDLE *handle)
{
USB4704 *usb = (USB4704 *)handle;

	delete usb;
}
};