Using RS-232 and Printing to LCD - Revision history

129.105.69.231: /* Getting Started */

2006-11-29T23:38:15Z

Getting Started

← Older revision		Revision as of 18:38, 29 November 2006
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	Go to [http://www.seetron.com/ www.seetron.com] for more info and tools for the LCD screen.		Go to [http://www.seetron.com/ www.seetron.com] for more info and tools for the LCD screen.


	==Getting Started==		==Getting Started==
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	2.Copy the file ''RS232Async_Messages.m'' into your work folder. This file contains a data structure that holds configuration parameters for the RS232_Send block within the BPI_216_Send subsystem. '''The model should automatically run the RS232Async_Messages script upon loading. If it doesn't, or if you clear your workspace later on, run the ''RS232Async_Messages.m'' script before compiling the program.''' Open the ''BPI_216_Send.mdl'' file and copy the BPI_216_Send block into your own model. The other blocks in BPI_216_Send.mdl are just for demonstration purposes.		2.Copy the file ''RS232Async_Messages.m'' into your work folder. This file contains a data structure that holds configuration parameters for the RS232_Send block within the BPI_216_Send subsystem. '''The model should automatically run the RS232Async_Messages script upon loading. If it doesn't, or if you clear your workspace later on, run the ''RS232Async_Messages.m'' script before compiling the program.''' Open the ''BPI_216_Send.mdl'' file and copy the BPI_216_Send block into your own model. The other blocks in BPI_216_Send.mdl are just for demonstration purposes.

	3.To output static, predefined text messages to the BPI-216 LCD display using the BPI_216_Send block, the system that is deciding which message to output needs to output a number of data type ''double'' (see ''double'' in the MATLAB help files for more information on data types). The BPI_216_Send subsystem will read this number and display the corresponding message. ''(Note: the default time step of BPI_216_Send is 0.01 seconds. BPI_216_Send’s time step must be an integer multiple of your main system’s time step.)''		3.To output static predefined text messages to the BPI-216 LCD display using the BPI_216_Send block, the system that is deciding which message to output needs to output a number of data type ''double'' (see ''double'' in the MATLAB help files for more information on data types). The BPI_216_Send subsystem will read this number and display the corresponding message. ''(Note: the default time step of BPI_216_Send is 0.01 seconds. BPI_216_Send’s time step must be an integer multiple of your main system’s time step.)''

	Figure 1 shows how to hook up the system:<br>		Figure 1 shows how to hook up the system:<br>

199.74.85.23: /* The maxPages variable */

2006-11-19T02:48:33Z

The maxPages variable

← Older revision		Revision as of 21:48, 18 November 2006
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	==The maxPages variable==		==The maxPages variable==
	The maxPages variable will set maximum number of "pages" your message can be; each page being one of the separate screens needed to display a long message (remember, Simulink doesn' have dynamic memory allocation for input/output variables, so you have to tell it how big the array is). The LCD screenn holds 32 characters, so the maximum number of characters (including white spaces) a message can contain is equal to 32*maxPages. There is also a local variable maxPages in the subfunction ''lcd_text''; '''both values of ''maxPages'' must match''' (unfortunately, global variables are not supported). A small value of ''maxPages'' will reduce the overhead memory and CPU cycles needed to run the system, so don't make ''maxPages'' larger than it has to be.		The maxPages variable will set maximum number of "pages" your message can be; each page being one of the separate screens needed to display a long message (remember, Simulink doesn't have dynamic memory allocation for input/output variables, so you have to tell it how big the array is). The LCD screenn holds 32 characters, so the maximum number of characters (including white spaces) a message can contain is equal to 32*maxPages. There is also a local variable maxPages in the subfunction ''lcd_text''; '''both values of ''maxPages'' must match''' (unfortunately, global variables are not supported). A small value of ''maxPages'' will reduce the overhead memory and CPU cycles needed to run the system, so don't make ''maxPages'' larger than it has to be.

	==Changing COM Ports==		==Changing COM Ports==

199.74.85.23: /* If the variable is numeric */

2006-11-19T02:46:10Z

If the variable is numeric

← Older revision		Revision as of 21:46, 18 November 2006
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	[[Image:RS232_lcd_blankspaces.png]]		[[Image:RS232_lcd_blankspaces.png]]

	You must manually set how many digits ''numtostr'' will display. Open the ''message_select'' m-function block, and scroll towards the bottom until you find the function header for ''numtostr''. Set number of integer places(int_p) and decimal places(dec_p) that you want displayed. If the inputted number has more integer places than int_p, the offending most significant digits will be lost. Negative numbers will need an additional integer place to hold the negative sign. Unused integer spaces will be filled in by blank spaces, and ~~unspecified~~ decimal places will be filled with zeros.		You must manually set how many digits ''numtostr'' will display. Open the ''message_select'' m-function block, and scroll towards the bottom until you find the function header for ''numtostr''. Set number of integer places(int_p) and decimal places(dec_p) that you want displayed. If the inputted number has more integer places than int_p, the offending most significant digits will be lost. Negative numbers will need an additional integer place to hold the negative sign. Unused integer spaces will be filled in by blank spaces, and unused decimal places will be filled with zeros.

	[[Image:RS232_lcd_set_numtostr.png]]		[[Image:RS232_lcd_set_numtostr.png]]

Hwang at 17:18, 11 August 2006

2006-08-11T17:18:33Z

← Older revision		Revision as of 12:18, 11 August 2006
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	__TOC__		__TOC__
			This tutorial will show how to print text and data to the Seetron BPI-216 LCD module.
	==Files==		==Files==
	Download the files you need here: [[Media:BPI_216_Send_v1.zip\|Matlab and Simulink files]].		Download the files you need here: [[Media:BPI_216_Send_v1.zip\|Matlab and Simulink files]].

Hwang: /* Integrating with your own model */

2006-08-11T17:17:03Z

Integrating with your own model

← Older revision		Revision as of 12:17, 11 August 2006
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	==Integrating with your own model==		==Integrating with your own model==
	To integrate this system into your own Simulink model, simply copy and paste the entire '''BPI_216_Send''' block, and copy the '''RS232Async_Messages.m''' file into your work directory. Then, in drop-down menu, go to '''File>Model Properties>Callback>PreloadFcn''' and enter ''RS232Async_Messages''. This will make the model run the RS232Async_Message script upon loading, or else you will have to run it manually before you compile the program.		To integrate this system into your own Simulink model, simply copy and paste the entire '''BPI_216_Send''' block, and copy the '''RS232Async_Messages.m''' file into your work directory. Then, in drop-down menu, go to '''File>Model Properties>Callback>PreloadFcn''' and enter ''RS232Async_Messages''. This will make the model run the RS232Async_Message script upon loading, or else you will have to run it manually before you compile the program.

			[[Image:RS232_LCD_preloadfcn.png]]

	==The maxPages variable==		==The maxPages variable==

Hwang: /* Displaying Variable Values */

2006-08-11T17:16:00Z

Displaying Variable Values

← Older revision		Revision as of 12:16, 11 August 2006
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	Load the program and change the gains while it is running. You should be able to change both the message ID and the data variable by manipulating the gains.		Load the program and change the gains while it is running. You should be able to change both the message ID and the data variable by manipulating the gains.

			==Integrating with your own model==
			To integrate this system into your own Simulink model, simply copy and paste the entire '''BPI_216_Send''' block, and copy the '''RS232Async_Messages.m''' file into your work directory. Then, in drop-down menu, go to '''File>Model Properties>Callback>PreloadFcn''' and enter ''RS232Async_Messages''. This will make the model run the RS232Async_Message script upon loading, or else you will have to run it manually before you compile the program.

	==The maxPages variable==		==The maxPages variable==

Hwang: /* Displaying Variable Values */

2006-08-11T17:10:42Z

Displaying Variable Values

← Older revision		Revision as of 12:10, 11 August 2006
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	[[Image:RS232_LCD_select_datatype.png]]		[[Image:RS232_LCD_select_datatype.png]]

			===Quick test===
			As a quick test, hook up the system like this:

			[[Image:RS232_LCD_quicktest1.png]]

			Then, enter the following into the message bank:

			[[Image:RS232_LCD_quicktest2.png]]

			Load the program and change the gains while it is running. You should be able to change both the message ID and the data variable by manipulating the gains.

	==The maxPages variable==		==The maxPages variable==

Hwang at 17:02, 11 August 2006

2006-08-11T17:02:42Z

← Older revision		Revision as of 12:02, 11 August 2006
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	Figure 1 shows how to hook up the system:<br>		Figure 1 shows how to hook up the system:<br>
	[[Image:RS232_LCD_connections.~~jpg~~]]<br>		[[Image:RS232_LCD_connections.png]]<br>
	''Figure 1''<br>		''Figure 1''<br>

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	See Figure 2:<br>		See Figure 2:<br>
	[[Image:RS232_LCD_messageselect.~~jpg~~]]<br>		[[Image:RS232_LCD_messageselect.png]]<br>
	''Figure 2''<br>		''Figure 2''<br>

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	'''''Note:''' you don't have to worry about the size of the variable for this case, because any number stored as type "double" takes up the same amount of space in the memory. On the other hand, a text string is an array of 8-bit integers, so the size in memory of a text string is determined by its length.''		'''''Note:''' you don't have to worry about the size of the variable for this case, because any number stored as type "double" takes up the same amount of space in the memory. On the other hand, a text string is an array of 8-bit integers, so the size in memory of a text string is determined by its length.''

	[[Image:RS232_LCD_add_data.~~jpg~~]]		[[Image:RS232_LCD_add_data.png]]

	Your system now looks something like this:		Your system now looks something like this:

	[[Image:RS232_LCD_data_setup.~~jpg~~]]		[[Image:RS232_LCD_data_setup.png]]

	Note the rate transitions:		Note the rate transitions:

	[[Image:RS232_LCD_ratetransition.~~jpg~~]]		[[Image:RS232_LCD_ratetransition.png]]

	Use the subfunction ''numtostr'' to convert it into a uint8 vector (because Simulink does not support string data types, we cannot simply use num2str for this). Simply insert numtostr(''yourdata'') in between strings, as shown in the figure below (Note:be sure to put blank spaces around ''numtostr()'', or you will get a compiler error.)		Use the subfunction ''numtostr'' to convert it into a uint8 vector (because Simulink does not support string data types, we cannot simply use num2str for this). Simply insert numtostr(''yourdata'') in between strings, as shown in the figure below (Note:be sure to put blank spaces around ''numtostr()'', or you will get a compiler error.)
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	'''''Warning:''' if you don't use "numtostr," the program will try to read your number as an ASCII code, not a numeric value.''		'''''Warning:''' if you don't use "numtostr," the program will try to read your number as an ASCII code, not a numeric value.''

	[[Image:RS232_lcd_blankspaces.~~jpg~~]]		[[Image:RS232_lcd_blankspaces.png]]

	You must manually set how many digits ''numtostr'' will display. Open the ''message_select'' m-function block, and scroll towards the bottom until you find the function header for ''numtostr''. Set number of integer places(int_p) and decimal places(dec_p) that you want displayed. If the inputted number has more integer places than int_p, the offending most significant digits will be lost. Negative numbers will need an additional integer place to hold the negative sign. Unused integer spaces will be filled in by blank spaces, and unspecified decimal places will be filled with zeros.		You must manually set how many digits ''numtostr'' will display. Open the ''message_select'' m-function block, and scroll towards the bottom until you find the function header for ''numtostr''. Set number of integer places(int_p) and decimal places(dec_p) that you want displayed. If the inputted number has more integer places than int_p, the offending most significant digits will be lost. Negative numbers will need an additional integer place to hold the negative sign. Unused integer spaces will be filled in by blank spaces, and unspecified decimal places will be filled with zeros.

	[[Image:RS232_lcd_set_numtostr.~~jpg~~]]		[[Image:RS232_lcd_set_numtostr.png]]

	===If the variable is a text string===		===If the variable is a text string===
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	#Under the '''data type''' menu, select '''uint8''' if data1 is a text string, or '''double''' if data1 is a numeric value.		#Under the '''data type''' menu, select '''uint8''' if data1 is a text string, or '''double''' if data1 is a numeric value.

	[[Image:RS232_LCD_select_datatype.~~jpg~~]]		[[Image:RS232_LCD_select_datatype.png]]

	==The maxPages variable==		==The maxPages variable==

Hwang: /* Specifying data types */

2006-08-11T16:57:01Z

Specifying data types

← Older revision		Revision as of 11:57, 11 August 2006
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	You should also specify the data type of the variable ('''uint8''' if the variable is text, '''double''' if it is numeric) at the function ''message_select''. ''Note: if your variable is numeric, the function may still work because Simulink chooses "double" by default. To make the model display port data types, go to the menu and select '''Format>Port/Signal Displays>Port Data Types'''.'' To specify data types (also see the figure below):		You should also specify the data type of the variable ('''uint8''' if the variable is text, '''double''' if it is numeric) at the function ''message_select''. ''Note: if your variable is numeric, the function may still work because Simulink chooses "double" by default. To make the model display port data types, go to the menu and select '''Format>Port/Signal Displays>Port Data Types'''.'' To specify data types (also see the figure below):

	#right-click on the '''~~message_select''' (~~Message Bank/Selector) block		#right-click on the '''Message Bank/Selector''' block
	#select '''Explore'''		#select '''Explore'''
	#Inside the '''Model Hierarchy''' frame, select '''BPI_216_Send'''.		#Inside the '''Model Hierarchy''' frame, select '''BPI_216_Send'''.

Hwang: /* Specifying data types */

2006-08-11T16:56:24Z

Specifying data types

← Older revision		Revision as of 11:56, 11 August 2006
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	You should also specify the data type of the variable ('''uint8''' if the variable is text, '''double''' if it is numeric) at the function ''message_select''. ''Note: if your variable is numeric, the function may still work because Simulink chooses "double" by default. To make the model display port data types, go to the menu and select '''Format>Port/Signal Displays>Port Data Types'''.'' To specify data types (also see the figure below):		You should also specify the data type of the variable ('''uint8''' if the variable is text, '''double''' if it is numeric) at the function ''message_select''. ''Note: if your variable is numeric, the function may still work because Simulink chooses "double" by default. To make the model display port data types, go to the menu and select '''Format>Port/Signal Displays>Port Data Types'''.'' To specify data types (also see the figure below):

	#right-click on the '''message_select''' block		#right-click on the '''message_select''' (Message Bank/Selector) block
	#select '''Explore'''		#select '''Explore'''
	#Inside the '''Model Hierarchy''' frame, select '''BPI_216_Send'''.		#Inside the '''Model Hierarchy''' frame, select '''BPI_216_Send'''.