Digital inputs & outputs - Revision history

NealEhardt at 03:40, 13 March 2009

2009-03-13T03:40:28Z

← Older revision		Revision as of 22:40, 12 March 2009
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⚫	[[Image:pinsbroughtout2.jpg\|right]]


	==Which pins are accessible on the 4520 prototyping board?==		==Which pins are accessible on the 4520 prototyping board?==

		⚫	[[Image:pinsbroughtout2.jpg\|right]]

	Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.		Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.
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⚫	[[Image:4520pindiagramdigitalports.jpg\|right]]


	===Digital I/O pins (five "ports")===		===Digital I/O pins (five "ports")===

		⚫	[[Image:4520pindiagramdigitalports.jpg\|right]]

	With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.		With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.

NealEhardt at 03:39, 13 March 2009

2009-03-13T03:39:32Z

← Older revision		Revision as of 22:39, 12 March 2009
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	~~<b>~~Which pins are accessible on the 4520 prototyping board?~~</b>~~		==Which pins are accessible on the 4520 prototyping board?==


	Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.		Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.
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	Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.		Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.



	[[Image:4520pindiagramdigitalports.jpg\|right]]		[[Image:4520pindiagramdigitalports.jpg\|right]]


	~~<b>~~Digital I/O pins (five "ports")~~</b>~~		===Digital I/O pins (five "ports")===

	With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.		With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.


⚫	[[Image:Digitalio.gif\|right]]


	~~<b>~~Demo circuit for digital inputs and outputs~~</b>~~		==Demo circuit for digital inputs and outputs==


		⚫	[[Image:Digitalio.gif\|right]]
	The 4520 board has 32 1K resistors-to-ground built in, and spaces for 32 LEDs to be inserted, as shown in the circuit below You can see that the resistors are isolated from and have no effect on the PIC unless the LED is inserted.		The 4520 board has 32 1K resistors-to-ground built in, and spaces for 32 LEDs to be inserted, as shown in the circuit below You can see that the resistors are isolated from and have no effect on the PIC unless the LED is inserted.

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	~~<b>~~Sample code~~</b>~~		==Sample code==

	[http://peshkin.mech.northwestern.edu/pic/code Link to all sample code here.]		[http://peshkin.mech.northwestern.edu/pic/code Link to all sample code here.]
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	switch bounce - most mechanical switches "bounce" which means they open and close several times when activated, over a period of a few mS. If this is a problem for your software, there are a lot of ways to debounce switches electronically. Better, write your software so it doesn't get confused by multiple open-close cycles.		switch bounce - most mechanical switches "bounce" which means they open and close several times when activated, over a period of a few mS. If this is a problem for your software, there are a lot of ways to debounce switches electronically. Better, write your software so it doesn't get confused by multiple open-close cycles.

			==See also==
			*[[PIC18F4520: Digital Inputs]]
			*[[PIC18F4520: Digital Outputs]]

LIMS at 02:18, 27 December 2007

2007-12-27T02:18:03Z

← Older revision		Revision as of 21:18, 26 December 2007
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	[[Image:Digitalio.gif\|right]]		[[Image:Digitalio.gif\|right]]


			<b>Demo circuit for digital inputs and outputs</b>

	The 4520 board has 32 1K resistors-to-ground built in, and spaces for 32 LEDs to be inserted, as shown in the circuit below You can see that the resistors are isolated from and have no effect on the PIC unless the LED is inserted.		The 4520 board has 32 1K resistors-to-ground built in, and spaces for 32 LEDs to be inserted, as shown in the circuit below You can see that the resistors are isolated from and have no effect on the PIC unless the LED is inserted.



	At right is a demo circuit for digital input and digital output. Two LEDs have been inserted, and a pull-up switch and 4.7K pull-down resistor added.		At right is a demo circuit for digital input and digital output. Two LEDs have been inserted, and a pull-up switch and 4.7K pull-down resistor added.

LIMS at 02:16, 27 December 2007

2007-12-27T02:16:56Z

← Older revision		Revision as of 21:16, 26 December 2007
Line 1:		Line 1:
	[[Image:pinsbroughtout2.jpg\|right]]		[[Image:pinsbroughtout2.jpg\|right]]


			<b>Which pins are accessible on the 4520 prototyping board?</b>

	Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.		Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.
Line 12:		Line 14:


			<b>Digital I/O pins (five "ports")</b>

	With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.		With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.

LIMS at 02:15, 27 December 2007

2007-12-27T02:15:51Z

← Older revision		Revision as of 21:15, 26 December 2007
Line 28:		Line 28:

	Pin D7 is intended as a digital output. When the PIC drives it high, the right LED illuminates, and otherwise not.		Pin D7 is intended as a digital output. When the PIC drives it high, the right LED illuminates, and otherwise not.




	<b>Sample code</b>		<b>Sample code</b>

LIMS at 02:15, 27 December 2007

2007-12-27T02:15:32Z

← Older revision		Revision as of 21:15, 26 December 2007
Line 28:		Line 28:

	Pin D7 is intended as a digital output. When the PIC drives it high, the right LED illuminates, and otherwise not.		Pin D7 is intended as a digital output. When the PIC drives it high, the right LED illuminates, and otherwise not.

			<b>Sample code</b>

			[http://peshkin.mech.northwestern.edu/pic/code Link to all sample code here.]

	The code digitalio.c is a complete C program that will compile and run.		The code digitalio.c is a complete C program that will compile and run.

LIMS at 02:13, 27 December 2007

2007-12-27T02:13:24Z

← Older revision		Revision as of 21:13, 26 December 2007
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	[[Image:Digitalio.gif]]		[[Image:Digitalio.gif\|right]]

LIMS at 02:13, 27 December 2007

2007-12-27T02:13:10Z

← Older revision		Revision as of 21:13, 26 December 2007
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	[[Image:pinsbroughtout2.jpg\|right]]		[[Image:pinsbroughtout2.jpg\|right]]


	Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.		Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.
Line 7:		Line 8:
	Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.		Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.


			[[Image:4520pindiagramdigitalports.jpg\|right]]



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	[[Image:~~4520pindiagramdigitalports~~.~~jpg\|right~~]]		[[Image:Digitalio.gif]]


	The 4520 board has 32 1K resistors-to-ground built in, and spaces for 32 LEDs to be inserted, as shown in the circuit below You can see that the resistors are isolated from and have no effect on the PIC unless the LED is inserted.		The 4520 board has 32 1K resistors-to-ground built in, and spaces for 32 LEDs to be inserted, as shown in the circuit below You can see that the resistors are isolated from and have no effect on the PIC unless the LED is inserted.


	[[Image:Digitalio.gif]]

	~~Above~~ is a demo circuit for digital input and digital output. Two LEDs have been inserted, and a pull-up switch and 4.7K pull-down resistor added.		At right is a demo circuit for digital input and digital output. Two LEDs have been inserted, and a pull-up switch and 4.7K pull-down resistor added.

	Pin C1 is intended as a digital input, and will be designated so in software. When pushbutton switch S1 is depressed, it brings input C1 high, and the left LED illuminates. Otherwise input C1 is held low by the 4.7K resistor to ground. (The LED and its resistor cannot be counted upon to hold input C1 low.)		Pin C1 is intended as a digital input, and will be designated so in software. When pushbutton switch S1 is depressed, it brings input C1 high, and the left LED illuminates. Otherwise input C1 is held low by the 4.7K resistor to ground. (The LED and its resistor cannot be counted upon to hold input C1 low.)

LIMS at 02:12, 27 December 2007

2007-12-27T02:12:15Z

← Older revision		Revision as of 21:12, 26 December 2007
Line 1:		Line 1:
		⚫	[[Image:pinsbroughtout2.jpg\|right]]

	Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.		Most pins on the PIC are brought out to easily accessible lines on the 4520 board. Feel free to connect to the few others as well.

Line 5:		Line 7:
	Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.		Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.


⚫	[[Image:pinsbroughtout2.jpg]]

	With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.		With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.


	[[Image:4520pindiagramdigitalports.jpg]]		[[Image:4520pindiagramdigitalports.jpg\|right]]

LIMS at 02:11, 27 December 2007

2007-12-27T02:11:34Z

← Older revision		Revision as of 21:11, 26 December 2007
Line 5:		Line 5:
	Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.		Most pins have several possible different input or output purposes, as evidenced by several names. Your software determines which purpose is in effect.

	[[Image:~~pinsbroughtout~~.jpg]]		[[Image:pinsbroughtout2.jpg]]

	With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.		With the exception of the positive voltage supply and ground pins, all pins on the PIC18F4520 can be used as digital I/O, however a few other pins (shown in gray below) are commonly utilized for communication instead of for digital I/O.