Template:Language - C Write Code - Revision history

Jdecoux at 19:02, 10 August 2018

2018-08-10T19:02:54Z

← Older revision		Revision as of 19:02, 10 August 2018
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	~~==Write Code==~~
	{{WriteCode_Intro\|C\|C}}		{{WriteCode_Intro\|C\|C}}

Mparadis at 21:17, 5 July 2018

2018-07-05T21:17:58Z

← Older revision		Revision as of 21:17, 5 July 2018
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	~~== Editing the Examples==~~
	To get our example code to run in a custom application, simply remove the calls to ''AskForDeviceParameters'' and ''PrintEventDescriptions'', and hard-code the addressing parameters for your application.

	~~If you are unsure what values to use for the addressing parameters, check the [[Finding The Addressing Information]] page.~~

	~~For instance:~~
	~~<syntaxhighlight lang=C>~~
	~~AskForDeviceParameters(&channelInfo, (PhidgetHandle)ch);~~

	~~prc = Phidget_setDeviceSerialNumber((PhidgetHandle)ch, channelInfo.deviceSerialNumber);~~
	~~CheckError(prc, "Setting DeviceSerialNumber", &(PhidgetHandle)ch);~~

	~~prc = Phidget_setHubPort((PhidgetHandle)ch, channelInfo.hubPort);~~
	~~CheckError(prc, "Setting HubPort", &(PhidgetHandle)ch);~~

	~~prc = Phidget_setIsHubPortDevice((PhidgetHandle)ch, channelInfo.isHubPortDevice);~~
	~~CheckError(prc, "Setting IsHubPortDevice", &(PhidgetHandle)ch);~~

	~~Phidget_setChannel((PhidgetHandle)ch, channelInfo.channel);~~
	~~CheckError(prc, "Setting Channel", &(PhidgetHandle)ch);~~

	~~if (channelInfo.netInfo.isRemote) {~~
	~~prc = Phidget_setIsRemote((PhidgetHandle)ch, channelInfo.netInfo.isRemote);~~
	~~CheckError(prc, "Setting IsRemote", &(PhidgetHandle)ch);~~

	~~if (channelInfo.netInfo.serverDiscovery) {~~
	~~prc = PhidgetNet_enableServerDiscovery(PHIDGETSERVER_DEVICEREMOTE);~~
	~~CheckEnableServerDiscoveryError(prc, &(PhidgetHandle)ch);~~
	~~} else {~~
	~~prc = PhidgetNet_addServer("Server", channelInfo.netInfo.hostname,~~
	~~channelInfo.netInfo.port, channelInfo.netInfo.password, 0);~~
	~~CheckError(prc, "Adding Server", &(PhidgetHandle)ch);~~
	}
	}
	~~</syntaxhighlight>~~

	~~Might become:~~

	~~<syntaxhighlight lang=C>~~
	~~prc = Phidget_setDeviceSerialNumber((PhidgetHandle)ch, 370114);~~
	~~CheckError(prc, "Setting DeviceSerialNumber", &(PhidgetHandle)ch);~~

	~~prc = Phidget_setHubPort((PhidgetHandle)ch, 2);~~
	~~CheckError(prc, "Setting HubPort", &(PhidgetHandle)ch);~~

	~~prc = Phidget_setIsHubPortDevice((PhidgetHandle)ch, 1);~~
	~~CheckError(prc, "Setting IsHubPortDevice", &(PhidgetHandle)ch);~~
	~~</syntaxhighlight>~~

	~~Notice that you can leave out any parameter not relevant to your application for simplicity.~~

	~~You can then manipulate the rest of the code as your application requires. A more in-depth description of programming with Phidgets follows in the Write Code section.~~

	==Write Code==		==Write Code==
	{{WriteCode_Intro\|C\|C}}		{{WriteCode_Intro\|C\|C}}

Mparadis at 21:27, 26 June 2018

2018-06-26T21:27:14Z

← Older revision		Revision as of 21:27, 26 June 2018
Line 53:		Line 53:

	==Write Code==		==Write Code==
	{{WriteCode_Intro\|C\|C~~\|os=Multiple~~}}		{{WriteCode_Intro\|C\|C}}

	=== Step One: Create and Address===		=== Step One: Create and Address===

Mparadis at 21:18, 26 June 2018

2018-06-26T21:18:42Z

← Older revision		Revision as of 21:18, 26 June 2018
Line 53:		Line 53:

	==Write Code==		==Write Code==
	{{WriteCode_Intro\|C\|C\|Multiple}}		{{WriteCode_Intro\|C\|C\|os=Multiple}}

	=== Step One: Create and Address===		=== Step One: Create and Address===

Mparadis at 21:09, 26 June 2018

2018-06-26T21:09:03Z

← Older revision		Revision as of 21:09, 26 June 2018
Line 53:		Line 53:

	==Write Code==		==Write Code==
	{{WriteCode_Intro\|C\|C}}		{{WriteCode_Intro\|C\|C\|Multiple}}

	=== Step One: Create and Address===		=== Step One: Create and Address===

Mparadis: /* Write Code */

2018-06-26T20:56:32Z

Write Code

← Older revision		Revision as of 20:56, 26 June 2018
Line 53:		Line 53:

	==Write Code==		==Write Code==
	{{WriteCode_Intro\|C}}		{{WriteCode_Intro\|C\|C}}

	=== Step One: Create and Address===		=== Step One: Create and Address===

Mparadis: /* Step Three: Do Things with the Phidget */

2018-06-22T15:52:42Z

Step Three: Do Things with the Phidget

← Older revision		Revision as of 15:52, 22 June 2018
Line 137:		Line 137:
	</syntaxhighlight>		</syntaxhighlight>

	If you are using multiple Phidgets in your program, check out our page on [[~~Using_Multiple_Phidgets~~]] for information on how to properly address them and use them in events.		If you are using multiple Phidgets in your program, check out our page on [[Using Multiple Phidgets]] for information on how to properly address them and use them in events.

	If events do not suit your needs, you can also poll the device directly for data using code like this:		If events do not suit your needs, you can also poll the device directly for data using code like this:

Jdecoux: Created page with "== Editing the Examples== To get our example code to run in a custom application, simply remove the calls to ''AskForDeviceParameters'' and ''PrintEventDescriptions'', and har..."

2018-06-20T21:19:42Z

Created page with "== Editing the Examples== To get our example code to run in a custom application, simply remove the calls to ''AskForDeviceParameters'' and ''PrintEventDescriptions'', and har..."

New page

== Editing the Examples==
To get our example code to run in a custom application, simply remove the calls to ''AskForDeviceParameters'' and ''PrintEventDescriptions'', and hard-code the addressing parameters for your application.

If you are unsure what values to use for the addressing parameters, check the [[Finding The Addressing Information]] page.

For instance:
<syntaxhighlight lang=C>
AskForDeviceParameters(&channelInfo, (PhidgetHandle)ch);

prc = Phidget_setDeviceSerialNumber((PhidgetHandle)ch, channelInfo.deviceSerialNumber);
CheckError(prc, "Setting DeviceSerialNumber", &(PhidgetHandle)ch);

prc = Phidget_setHubPort((PhidgetHandle)ch, channelInfo.hubPort);
CheckError(prc, "Setting HubPort", &(PhidgetHandle)ch);

prc = Phidget_setIsHubPortDevice((PhidgetHandle)ch, channelInfo.isHubPortDevice);
CheckError(prc, "Setting IsHubPortDevice", &(PhidgetHandle)ch);

Phidget_setChannel((PhidgetHandle)ch, channelInfo.channel);
CheckError(prc, "Setting Channel", &(PhidgetHandle)ch);

if (channelInfo.netInfo.isRemote) {
prc = Phidget_setIsRemote((PhidgetHandle)ch, channelInfo.netInfo.isRemote);
CheckError(prc, "Setting IsRemote", &(PhidgetHandle)ch);

if (channelInfo.netInfo.serverDiscovery) {
prc = PhidgetNet_enableServerDiscovery(PHIDGETSERVER_DEVICEREMOTE);
CheckEnableServerDiscoveryError(prc, &(PhidgetHandle)ch);
} else {
prc = PhidgetNet_addServer("Server", channelInfo.netInfo.hostname,
channelInfo.netInfo.port, channelInfo.netInfo.password, 0);
CheckError(prc, "Adding Server", &(PhidgetHandle)ch);
}
}
</syntaxhighlight>

Might become:

<syntaxhighlight lang=C>
prc = Phidget_setDeviceSerialNumber((PhidgetHandle)ch, 370114);
CheckError(prc, "Setting DeviceSerialNumber", &(PhidgetHandle)ch);

prc = Phidget_setHubPort((PhidgetHandle)ch, 2);
CheckError(prc, "Setting HubPort", &(PhidgetHandle)ch);

prc = Phidget_setIsHubPortDevice((PhidgetHandle)ch, 1);
CheckError(prc, "Setting IsHubPortDevice", &(PhidgetHandle)ch);
</syntaxhighlight>

Notice that you can leave out any parameter not relevant to your application for simplicity.

You can then manipulate the rest of the code as your application requires. A more in-depth description of programming with Phidgets follows in the Write Code section.

==Write Code==
{{WriteCode_Intro|C}}

=== Step One: Create and Address===
You will need to create your Phidget object in your code. For example, we can create a digital input object like this:
<syntaxhighlight lang=c>
PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);
</syntaxhighlight>

Next, we can address which Phidget we want to connect to by setting parameters such as ''DeviceSerialNumber''.

<syntaxhighlight lang=C>
Phidget_setDeviceSerialNumber((PhidgetHandle)ch, 496911);
</syntaxhighlight>

Although we are not including it on this page, you should handle the return codes of all Phidget functions. Here is an example of the previous code with error handling:
<syntaxhighlight lang=C>
PhidgetReturnCode prc;
PhidgetDigitalInputHandle ch;

prc = PhidgetDigitalInput_create(&ch);
if (prc != EPHIDGET_OK) {
fprintf(stderr, "Runtime Error -> Creating DigitalInput: \n\t");
fprintf(stderr, "Code: 0x%x\n", error);
return 1;
}

prc = Phidget_setDeviceSerialNumber((PhidgetHandle)ch, 496911);
if (prc != EPHIDGET_OK) {
fprintf(stderr, "Runtime Error -> Setting DeviceSerialNumber: \n\t");
fprintf(stderr, "Code: 0x%x\n", error);
return 1;
}
</syntaxhighlight>

=== Step Two: Open and Wait for Attachment===

After we have specified which Phidget to connect to, we can open the Phidget object like this:
<syntaxhighlight lang=C>
Phidget_openWaitForAttachment((PhidgetHandle)ch, 5000);
</syntaxhighlight>

To use a Phidget, it must be plugged in (attached). We can handle this by calling ''openWaitForAttachment'', which will block indefinitely until a connection is made, or until the timeout value is exceeded. Simply calling ''open'' does not guarantee you can use the Phidget immediately.

Alternately, you could verify the device is attached by using event driven programming and tracking the attach events.

To use events to handle attachments, we have to modify our code slightly:
<syntaxhighlight lang=C>
PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);

Phidget_setOnAttachHandler((PhidgetHandle)ch, onAttachHandler, null);

Phidget_openWaitForAttachment((PhidgetHandle)ch, 5000);
</syntaxhighlight>

Next, we have to declare the function that will be called when an attach event is fired - in this case the function ''onAttachHandler'' will be called:
<syntaxhighlight lang=C>
static void CCONV onAttachHandler(PhidgetHandle ph, void *ctx) {
printf("Phidget attached!\n");
}
</syntaxhighlight>

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

=== Step Three: Do Things with the Phidget ===
We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:
<syntaxhighlight lang=C>
PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);

Phidget_setOnAttachHandler((PhidgetHandle)ch, onAttachHandler, null);
PhidgetDigitalInput_setOnStateChangeHandler(ch, onStateChangeHandler, null);

Phidget_openWaitForAttachment((PhidgetHandle)ch, 5000);
</syntaxhighlight>

This code will connect a function to an event. In this case, the ''onStateChangeHandler'' function will be called when there has been a change to the channel's input. Next, we need to create the ''onStateChangeHandler'' function:
<syntaxhighlight lang=C>
static void CCONV onStateChangeHandler(PhidgetDigitalInputHandle ph, void *ctx, int state) {
printf("State: %d\n", state);
}
</syntaxhighlight>

If you are using multiple Phidgets in your program, check out our page on [[Using_Multiple_Phidgets]] for information on how to properly address them and use them in events.

If events do not suit your needs, you can also poll the device directly for data using code like this:
<syntaxhighlight lang=C>
int state;
PhidgetDigitalInput_getState(ch, &state);
printf("State: %d\n", state);
</syntaxhighlight>

'''Important Note:''' There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an error code, and a specific nonsensical result. See more information on this on our page for [[Unknown Values]].

====Enumerations====

Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in C will take the form of '''ENUMERATION_NAME'''.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:
<syntaxhighlight lang=C>
SENSOR_TYPE_1142
</syntaxhighlight>
and specifying a K-Type thermocouple for a temperature sensor would be:
<syntaxhighlight lang=C>
THERMOCOUPLE_TYPE_K
</syntaxhighlight>
The Phidget error code for timing out could be specified as:
<syntaxhighlight lang=C>
EPHIDGET_TIMEOUT
</syntaxhighlight>

You can find the Enumeration Type under the ''Enumerations'' section of the {{Phidget22API}} for your device, and the Enumeration Name in the drop-down list within.

=== Step Four: Close and Delete ===
At the end of your program, be sure to close and delete your device:
<syntaxhighlight lang=C>
Phidget_close((PhidgetHandle)ch);
PhidgetDigitalInput_delete(&ch);
</syntaxhighlight>