USB Communication using PIC microcontrollers - Revision history

DavidMeyer at 21:57, 4 September 2012

2012-09-04T21:57:48Z

← Older revision		Revision as of 16:57, 4 September 2012
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	'''*Under Construction*'''

	==USB Overview==		==USB Overview==

DavidMeyer at 18:17, 9 July 2012

2012-07-09T18:17:53Z

← Older revision		Revision as of 13:17, 9 July 2012
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	Here is the API [[Media:HIDAPI.zip\|documentation]], which explains what each function does.		Here is the API [[Media:HIDAPI.zip\|documentation]], which explains what each function does.

			==Matlab and the HID API==

DavidMeyer: /* Processing and the HID API */

2012-07-09T18:17:06Z

Processing and the HID API

← Older revision		Revision as of 13:17, 9 July 2012
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	The main file includes the typical functions, setup() and draw(), as well as an openPic() function used to search the computer for a connected PIC microcontroller and open it for communication.		The main file includes the typical functions, setup() and draw(), as well as an openPic() function used to search the computer for a connected PIC microcontroller and open it for communication.

			Here is the API [[Media:HIDAPI.zip\|documentation]], which explains what each function does.

DavidMeyer: /* Processing and the HID API */

2012-07-09T17:27:51Z

Processing and the HID API

← Older revision		Revision as of 12:27, 9 July 2012
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	==Processing and the HID API==		==Processing and the HID API==

	To send and receive USB packets in Processing on the computer, we use a Java Native Interface library which uses C libraries to communicate via USB. Documentation and downloads for this library can be found [http://code.google.com/p/javahidapi/ here]. ~~Attached~~ is the Processing sketch used to interface with the demo board described above.		To send and receive USB packets in Processing on the computer, we use a Java Native Interface library which uses C libraries to communicate via USB. Documentation and downloads for this library can be found [http://code.google.com/p/javahidapi/ here]. This is the [[Media:Processing_USBExample.zip\|Processing sketch]] used to interface with the demo board described above.

			The code directory contains both the .jar file containing the Java library, and the .dll, .jnilib, and .so files containing the native USB libraries. These files need to be here, but do not require editing.

			In the sketch itself, the '''USBListener''' file defines a Thread which listens to the USB port. The function pic.read() will wait until the USB buffer is not empty, and then place the first-in data into the specified variable. This thread is also a good place to update all state variables and send out data to the PIC using pic.write(). The '''HIDManager''' extends the HIDManager class defined in the API. This class defines callback functions which are called whenever a device is added or removed.

			The main file includes the typical functions, setup() and draw(), as well as an openPic() function used to search the computer for a connected PIC microcontroller and open it for communication.

DavidMeyer: /* Demo */

2012-07-09T17:20:06Z

Demo

← Older revision		Revision as of 12:20, 9 July 2012
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	===Demo===		===Demo===

	~~Attached~~ ~~here~~ is an example project for the PIC32MX250F128B. ~~[[Media:USBExample.zip]]~~		This [[Media:USBExample.zip\|MPLABX Project Directory]] is an example project written for the PIC32MX250F128B.

	This demo communicated with the processing demo explained below, using the 28-DIP package for the pic32 and the following pinout.		This demo communicated with the processing demo explained below, using the 28-DIP package for the pic32 and the following pinout.

DavidMeyer: /* Add Application-Specific USB files */

2012-07-09T17:19:01Z

Add Application-Specific USB files

← Older revision		Revision as of 12:19, 9 July 2012
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	The file attached below is a zip containing examples of these four files. This example provides generic USB HID operation under Microchip's VendorID (1240) and a ProductID of 0, operating in USB_INTERRUPT mode (described below).		The file attached below is a zip containing examples of these four files. This example provides generic USB HID operation under Microchip's VendorID (1240) and a ProductID of 0, operating in USB_INTERRUPT mode (described below).

	[[Media:PIC32_USB_Files.zip]]		[[Media:PIC32_USB_Files.zip\|PIC32_USB_Files]]

	=== Microchip Stack Bug Notes ===		=== Microchip Stack Bug Notes ===

DavidMeyer at 17:00, 9 July 2012

2012-07-09T17:00:18Z

← Older revision		Revision as of 12:00, 9 July 2012
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	==Processing and the HID API==		==Processing and the HID API==

			To send and receive USB packets in Processing on the computer, we use a Java Native Interface library which uses C libraries to communicate via USB. Documentation and downloads for this library can be found [http://code.google.com/p/javahidapi/ here]. Attached is the Processing sketch used to interface with the demo board described above.

DavidMeyer at 16:41, 9 July 2012

2012-07-09T16:41:33Z

@@ Line 120: / Line 120: @@
+    }
+ }
 ==Processing and the HID API==

DavidMeyer at 15:17, 9 July 2012

2012-07-09T15:17:42Z

← Older revision		Revision as of 10:17, 9 July 2012
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	USB_POLLING requires the developer to call USBDeviceTasks() manually faster than the minimum rate, whereas USB_INTERRUPT handles all timing automatically. In the demo, we use USB_INTERRUPT to handle this timing.		USB_POLLING requires the developer to call USBDeviceTasks() manually faster than the minimum rate, whereas USB_INTERRUPT handles all timing automatically. In the demo, we use USB_INTERRUPT to handle this timing.

			Below is some sample code in the while loop of a main function of PIC communicating via USB.
			while(1){
			if((USBGetDeviceState() < CONFIGURED_STATE) \|\|
			(USBIsDeviceSuspended() == TRUE))
			{
			//Either the device is not configured or we are suspended,
			// so we don't want to execute any USB related application code
			continue; //go back to the top of the while loop
			}
			if(!HIDRxHandleBusy(USBOutHandle)) //Check if data was received from the host.
			{
			//Do something with the data
			ToSendDataBuffer[0] = ReceivedDataBuffer[0];
			//Re-arm the OUT endpoint for the next packet
			USBOutHandle = HIDRxPacket(HID_EP,(BYTE*)&ReceivedDataBuffer,64);
			}
			if(!HIDTxHandleBusy(USBInHandle)){
			// Send out new data
			USBInHandle = HIDTxPacket(HID_EP,(BYTE*)&ToSendDataBuffer[0],64);
			}
			}

	==Processing and the HID API==		==Processing and the HID API==

DavidMeyer: /* Add Application-Specific USB files */

2012-07-03T23:11:25Z

Add Application-Specific USB files

← Older revision		Revision as of 18:11, 3 July 2012
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	The file attached below is a zip containing examples of these four files. This example provides generic USB HID operation under Microchip's VendorID (1240) and a ProductID of 0, operating in USB_INTERRUPT mode (described below).		The file attached below is a zip containing examples of these four files. This example provides generic USB HID operation under Microchip's VendorID (1240) and a ProductID of 0, operating in USB_INTERRUPT mode (described below).

	[[~~File~~:PIC32_USB_Files.zip]]		[[Media:PIC32_USB_Files.zip]]

	=== Microchip Stack Bug Notes ===		=== Microchip Stack Bug Notes ===