Lock up with Phidgets

Enable server discovery and logging

The first thing we should do in our main function is enable server discovery and enable Phidget logging.

  
result = PhidgetLogging_enable(PHIDGET_LOG_INFO, "/path/to/logfile");
if (result != EPHIDGET_OK) {
	Phidget_log(PHIDGET_LOG_ERROR, "failed to enable logging");
	return 1;
}
result = PhidgetNet_enableServerDiscovery(PHIDGETSERVER_DEVICE);
if (result != EPHIDGET_OK) {
	Phidget_log(PHIDGET_LOG_ERROR, "failed to enable server discovery");
	return 1;
}

Create and Initialize PhidgetRFID

  
#define RFID_SERIALNUM 377511
...
int main(void){
...
	PhidgetRFIDHandle rfid;
	PhidgetReturnCode result;
	...
	result = Phidget_setDeviceSerialNumber(rfid, RFID_SERIALNUM);
	if (result != EPHIDGET_OK) {
		Phidget_log(PHIDGET_LOG_ERROR, "failed to set device serial number");
		return 1;
	}
	result = PhidgetRFID_setOnTagHandler(rfid, onTagHandler, NULL);
	if (result != EPHIDGET_OK) {
		Phidget_log(PHIDGET_LOG_ERROR, "failed to set on tag handler");
		return 1;
	}
	result = Phidget_openWaitForAttachment(rfid, 2000);
	if (result != EPHIDGET_OK) {
		Phidget_log(PHIDGET_LOG_ERROR, "failed to open");
		return 1;
	}
	result = PhidgetRFID_setAntennaEnabled(rfid, 1);
	if (result != EPHIDGET_OK) {
		Phidget_log(PHIDGET_LOG_ERROR, "failed to set antenna enabled");
		return 1;
	}
...
}

Create and Initialize everything else

Aside from the PhidgetRFID, we will also need to create and initialize the following:

• PhidgetDigitalOutput - this object will control the relay that will in turn control the solenoid.
• PhidgetDigitalInput - this object will interface with the magnetic contact switch. Subscribe to the change event and get notified immediately if the door has been opened or closed.
• PhidgetDictionary - this channel will allow us to send/receieve information from the web page. Subscribe to the change event and get notified immediately if the user wants to remotely unlock the door.

Use the PhidgetRFID template above to create the channels listed above, or, take a look at the provided code.

Main code

The main code for this project is fairly simple:

• Our main loop first checks if the dictionary has been updated. dictionaryUpdate will only be true if a user has remotely unlocked the door via the web page. If they have, we will recieve a onDictionaryUpdate event.
• Next, we check if tagRead is true. This value is also updated via an event that we subscribed to earlier. When the PhidgetRFID detects a tag, it will notify our program through the onTagHandler event. We can then check if the tag has an expected value, and if so, unlock the door.
• We also have the onStateChangeHandler event which will notify us when the state of the magnetic switch has changed. When this happens, we simply update the PhidgetDictionary and the user can see the current state of the door via the web page.

int tagRead = 0; //flag that is used in main loop
int dictionaryUpdate = 0; //flag that is used in main loop
...
//Update handlers for PhidgetRFID, PhidgetDigitalInput, and PhidgetDictionary
void CCONV
onTagHandler(PhidgetRFIDHandle ch, void *ctx, char* tag, PhidgetRFID_Protocol protocol) {
	tagRead = 1;
	strcpy(name, tag);
	Phidget_log(PHIDGET_LOG_INFO, "got tag - %s", name);
}
void CCONV
onDictionaryUpdate(PhidgetDictionaryHandle ch, void *ctx, const char *key, const char* value){
	if(strcmp(key,"remoteopen") == 0)
		if(strcmp(value, "1") == 0)
			dictionaryUpdate = 1;
}
void CCONV
onStateChangeHandler(PhidgetDigitalInputHandle ch, void* context, int state){
	if(state){
		PhidgetDictionary_set(dict,"isDoorOpen","Door is closed");
		Phidget_log(PHIDGET_LOG_INFO, "Door is closed");
	}
	else{
		PhidgetDictionary_set(dict,"isDoorOpen","Door is open");
		Phidget_log(PHIDGET_LOG_INFO, "Door is open");
	}
}
...
//Function that activates relay
void changeDoorState(PhidgetDigitalOutputHandle ch, int state){
	PhidgetReturnCode result;
	result = PhidgetDigitalOutput_setState(ch, state);
	if(result != EPHIDGET_OK){
		const char* error;
		Phidget_getErrorDescription(result, &error);
		Phidget_log(PHIDGET_LOG_ERROR, "failed to set door state - %s", error);
		return;
	}
	Phidget_log(PHIDGET_LOG_INFO, "door state set to %d", state);
	logData(state);

}
...
int main(void){
...
	while (1) {
		if(dictionaryUpdate){ //if remote open has been activated
			Phidget_log(PHIDGET_LOG_INFO,"Remotely opening door");
			dictionaryUpdate = 0;
			changeDoorState(dig, ON);
			ssleep(5);//activate solenoid for 5 seconds 
			changeDoorState(dig,OFF);
			PhidgetDictionary_set(dict,"remoteopen","0");
		}
		if (tagRead) {
			int activate = 0;
			tagRead = 0;
			if (strcmp(name, "User1") == 0)
				activate = 1;
			else if (strcmp(name, "User2") == 0) 
				activate = 1;
			if(activate){
				changeDoorState(dig, ON);
				ssleep(5);//activate solenoid for 5 seconds
				changeDoorState(dig,OFF);
			}
		}
		sleep(1);
	}
...
}

Step 3: Graph using vis.js

To start, you can take a look at the doorlock.html file that is included with this project. This file should be placed at /var/phidgets/www

For my program, the door status data was logged to /usr/userapps/doorlock/data/doorstatus.txt, therefore, in order for my web page to access the file, I created a link to the data folder at my webservers docroot location.

The reference to this folder is made in the loadDataGraph() function as shown below:

function loadDataGraph(){
var url = '/doordata/doorstate.txt';
...

Graphing was done using vis.js

The installation project will detail how to remotely access your web page. For extra information on remotely accessing your web page, check out this project.

Stay tuned for the installation project!