NU32v2: Using the LS7183 Quadrature Clock Converter - Revision history

Lynch at 11:28, 16 January 2016

2016-01-16T11:28:29Z

← Older revision		Revision as of 06:28, 16 January 2016
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			'''THIS PAGE REFERS TO A PRE-RELEASE VERSION OF THE NU32 PIC32 DEVELOPMENT BOARD. FOR INFORMATION, SAMPLE CODE, AND VIDEOS RELATED TO THE PRODUCTION VERSION (2016 AND LATER), AND TO THE CORRESPONDING BOOK "EMBEDDED COMPUTING AND MECHATRONICS WITH THE PIC32 MICROCONTROLLER," VISIT [[NU32\|THE NU32 PAGE]].'''


	The LS7183 quadrature clock converter is a chip used to convert quadrature signals from encoders into up and down counts that can be sent to a microchip.		The LS7183 quadrature clock converter is a chip used to convert quadrature signals from encoders into up and down counts that can be sent to a microchip.

2011-02-23T02:21:52Z

Details

← Older revision		Revision as of 21:21, 22 February 2011
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	* VSS (GND) -> 1X		* VSS (GND) -> 1X
	* VDD (3.3V) -> 2X		* VDD (3.3V) -> 2X
	* Float (don't connect to anything) -> 4X		* Float (don't connect to anything; in practice, though, you may have to connect it to a floating input of the PIC32 to get reliable behavior) -> 4X

	The UP and DOWN count pins should be connected to external counters on the PIC32.		The UP and DOWN count pins should be connected to external counters on the PIC32.

2011-02-09T17:32:41Z

Sample Code

← Older revision		Revision as of 12:32, 9 February 2011
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	== Sample Code ==		== Sample Code ==

	The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]]) that will increment with each pulse received from the LS7183. The ~~full code~~ example ~~adds~~ the ~~up counts, subtracts the down counts and adjusts for roll-over for a variable (bigcount) that represents the position (in relative counts) of the motor. The example sends this~~ position via RS232 to your PC.		The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]]) that will increment with each pulse received from the LS7183. The example sends the encoder position via RS232 to your PC.

	The main code shown below can be placed in an ISR if you want to read the encoder at a given ~~frequency~~.		The main piece of code shown below reads the UP and DOWN counters. With a variable called bigcount, it adds the the recent UP counts, subtracts the down counts and adjusts for roll-over of the counters. The full code placed this code in the main while loop, but this code can be placed in an ISR if you want to read the encoder at a given rate.

	<pre>		<pre>

2011-02-09T17:30:42Z

Sample Code

← Older revision		Revision as of 12:30, 9 February 2011
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	== Sample Code ==		== Sample Code ==

	The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]]).		The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]]) that will increment with each pulse received from the LS7183. The full code example adds the up counts, subtracts the down counts and adjusts for roll-over for a variable (bigcount) that represents the position (in relative counts) of the motor. The example sends this position via RS232 to your PC.

			The main code shown below can be placed in an ISR if you want to read the encoder at a given frequency.

			<pre>
			count0 = ReadTimer4(); // in your routine this must be done at least every 32000
			// encoder counts to avoid rollover ambiguity
			count1 = ReadTimer5();

			bigcount += count0 - last0; // add on the recent up-counts, since the last time

			if (count0 < last0){
			bigcount += 65536; // count0 only increments, so if it got lower
			//it must have rolled over
			}

			last0 = count0;

			bigcount -= count1 - last1; // we're not worrying about rollover of the 32 bit bigcount total

			if (count1 < last1){
			bigcount -= 65536;
			}

			last1 = count1;

			</pre>

2011-02-09T17:25:09Z

Sample Code

← Older revision		Revision as of 12:25, 9 February 2011
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	== Sample Code ==		== Sample Code ==

	The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]] ~~for discussion~~).		The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]]).

2011-02-09T17:25:01Z

Sample Code

← Older revision		Revision as of 12:25, 9 February 2011
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	== Sample Code ==		== Sample Code ==

	The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|~~external~~ ~~counters~~]] for discussion).		The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|Counters and Timers]] for discussion).

2011-02-09T17:24:44Z

Sample Code

← Older revision		Revision as of 12:24, 9 February 2011
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	== Sample Code ==		== Sample Code ==

	The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers:External Counter]] for discussion ~~of external counters~~ .		The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers#External Counter\|external counters]] for discussion).

2011-02-09T17:22:40Z

Sample Code

← Older revision		Revision as of 12:22, 9 February 2011
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	== Sample Code ==		== Sample Code ==

			The full code can be downloaded [[Media:NU32v2_Encoder.c \| here]]. The code configures 2 external counters (see [[NU32v2: Counters and Timers:External Counter]] for discussion of external counters .

2011-02-09T17:20:10Z

Details

← Older revision		Revision as of 12:20, 9 February 2011
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	[[Image:LS7183.png\|center\|thumb\|400 px]]		[[Image:LS7183.png\|center\|thumb\|400 px]]

	The resistor bias is used to control the pulse width of the up and down counts. The mode (1X, 2X, 4X) is used to multiply the ~~quadrate~~ clock rate by 1, 2 or 4. The mode is selected by connecting MODE to		The resistor bias is used to control the pulse width of the up and down counts. The mode (1X, 2X, 4X) is used to multiply the quadrature clock rate by 1, 2 or 4. The mode is selected by connecting MODE to
	* VSS (GND) -> 1X		* VSS (GND) -> 1X
	* VDD (3.3V) -> 2X		* VDD (3.3V) -> 2X

2011-02-09T17:19:50Z

Details

← Older revision		Revision as of 12:19, 9 February 2011
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	The resistor bias is used to control the pulse width of the up and down counts. The mode (1X, 2X, 4X) is used to multiply the quadrate clock rate by 1, 2 or 4. The mode is selected by connecting MODE to		The resistor bias is used to control the pulse width of the up and down counts. The mode (1X, 2X, 4X) is used to multiply the quadrate clock rate by 1, 2 or 4. The mode is selected by connecting MODE to
	** VSS (GND) -> 1X		* VSS (GND) -> 1X
	** VDD (3.3V) -> 2X		* VDD (3.3V) -> 2X
	** Float (don't connect to anything) -> 4X		* Float (don't connect to anything) -> 4X

	The UP and DOWN count pins should be connected to external counters on the PIC32.		The UP and DOWN count pins should be connected to external counters on the PIC32.