Matrix Orbital GLC24064 User manual

GLC24064
Technical Manual
Revision: 2.0

Contents
Contents ii
1 Introduction 1
1.1 What to Expect From the GLC24064 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 What Not to Expect From the GLC24064 . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 mogd.exe ............................................ 1
1.4 TryingOuttheGLC24064 ................................... 2
1.4.1 Here’swhattodo: ................................... 3
1.5 ManualOver-ride........................................ 4
1.6 MemoryChipLockDown ................................... 4
2 Connections 5
2.1 Power .............................................. 5
2.1.1 Power Connection (4 pin header) . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1.2 FivevoltPowerCable ................................. 7
2.1.3 Wide Voltage with Efficient Switching Power Supply (VPT) . . . . . . . . . . . . . 8
2.1.4 Power Connection (DB-9 Connector) . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.2 Communications ........................................ 10
2.2.1 RS-232 Communications and DB-9 Connector pinout . . . . . . . . . . . . . . . . 10
2.2.2 RS-232 Communication through the Power Connector . . . . . . . . . . . . . . . . 10
2.2.3 I2CCommunications.................................. 11
2.2.4 ACK .......................................... 12
2.3 GeneralPurposeOutput..................................... 13
3 Displaying Text 14
3.1 General ............................................. 14
3.2 WritingTexttotheDisplay................................... 14
3.3 TextCommands......................................... 15
3.3.1 AutoScrollOn(25481) ................................ 15
3.3.2 AutoScrollOff(25482)................................ 15
3.3.3 Set Text Insertion Point (254 71 [col] [row]) . . . . . . . . . . . . . . . . . . . . . . 15
3.3.4 Set Current Text Insertion Point to top Left (254 72) . . . . . . . . . . . . . . . . . 15
3.3.5 Set Text Insertion Point Using Pixel Values (254 121 [x][y]) . . . . . . . . . . . . . 15
3.3.6 Set Current Font (254 49 [font ID]) . . . . . . . . . . . . . . . . . . . . . . . . . . 16
3.3.7 Set Font Metrics (254 50 [metrics]) . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4 Displaying Graphics 16
4.1 General ............................................. 16
4.2 GraphicsCommands ...................................... 17
4.2.1 Set Drawing Color (254 99 [color]) . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2.2 Draw Line (254 108 [x1][y1][x2][y2]) . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2.3 Continue Line (254 101 [x][y]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2.4 Put Pixel (254 112 [x][y]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2.5 Draw Outline Rectangle (254 114 [color][x1][y1][x2][y2]) . . . . . . . . . . . . . . 18
Matrix Orbital GLC24064 ii

4.2.6 Draw Solid Rectangle (254 120 [color][x1][y1][x2][y2]) . . . . . . . . . . . . . . . 18
4.2.7 Initialize Bar Graph (254 103 [ref][type][x1][y1][x2][y2]) . . . . . . . . . . . . . . 18
4.2.8 Write to Bar Graph (254 105 [reference number][value]) . . . . . . . . . . . . . . . 19
4.2.9 Display Saved Bitmap (254 98 [reference number][x][y]) . . . . . . . . . . . . . . . 19
4.2.10 Direct Screen Write Bitmap (254 100 [x1][y1][x2][y2][data]{[data]}) . . . . . . . . 19
4.2.11 Initialize Strip Chart (254 106 [ref][x1][y1][x2][y2]) . . . . . . . . . . . . . . . . . 20
4.2.12 Shift Strip Chart (254 107 [ref]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.3 FlowControl .......................................... 20
4.3.1 Enter Flow Control Mode (254 58 [full][empty]) . . . . . . . . . . . . . . . . . . . 21
4.3.2 Exit Flow Control Mode (254 59) . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5 Fonts and Graphics Files 21
5.1 General ............................................. 21
5.2 Usingmogd.exe......................................... 22
5.3 Commands ........................................... 22
5.3.1 Erase File (254 176 [type] [ref]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.3.2 Purge Memory (254 33 89 33) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.3.3 Upload Font (254 36 [ref] [file size] [file data]) . . . . . . . . . . . . . . . . . . . . 23
5.3.4 Upload Bitmap (254 94[ref] [file size] [file data]) . . . . . . . . . . . . . . . . . . . 23
5.4 WorkingwithFontFiles .................................... 23
5.4.1 FontFileinTableForm ................................ 23
5.4.2 Uploading the File to the Module . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.4.3 ASampleFontFile................................... 25
5.5 WorkingwithBitmapFiles................................... 27
6 Miscellaneous Commands 27
6.1 General ............................................. 27
6.1.1 ClearDisplay(25488)................................. 27
6.1.2 Set Contrast (254 80 [contrast]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1.3 Set Contrast and Save (254 145 [contrast]) . . . . . . . . . . . . . . . . . . . . . . 28
6.1.4 Backlight On (254 66 [minutes]) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1.5 BacklightOff(25470)................................. 28
6.1.6 General Purpose Output On (254 86) . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1.7 General Purpose Output Off (254 87) . . . . . . . . . . . . . . . . . . . . . . . . . 28
6.1.8 Set I2C Address 254 51 [address]) . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.1.9 Read Module Type (254 55) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
6.1.10 Set RS-232 Port Speed (254 57 [speed]) . . . . . . . . . . . . . . . . . . . . . . . . 29
6.1.11 Set Serial Number (254 52 [byte1] [byte2] . . . . . . . . . . . . . . . . . . . . . . . 30
6.1.12 Read Serial Number (254 53) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
6.1.13 Read Version Number (254 54) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
7 Appendix: Command Summary 30
7.1 General ............................................. 30
7.2 IssuingCommands ....................................... 30
7.3 OnNumbers........................................... 31
7.3.1 ASCIICharacters ................................... 31
7.4 TextCommands......................................... 32
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7.5 GraphicsCommands ...................................... 33
7.6 FileSystemCommands..................................... 34
7.7 MiscellaneousCommands ................................... 35
8 Appendix: Specifications 37
8.1 Options ............................................. 40
Matrix Orbital GLC24064 iv

1 Introduction
The GLC24064 is equipped with the following features;
•240 x 64 pixel graphics display
•Text display using built in or user supplied fonts
•Adjustable contrast
•Backlighting
•RS-232 or I2C communications
1.1 What to Expect From the GLC24064
The GLC24064 is designed as the display unit for an associated controller. The controller may be
anything from a single board, special purpose micro-controller, to a PC depending on the application. This
controller is responsible for what is displayed on the screen of the display.
The display provides a simple command structure which allows both text and graphics to be transferred to
the screen. Text fonts (and graphics, if desired) are stored in the display’s flash ROM and may be regarded as
’permanent’, in that they will survive power-off periods and will not change until explicitly reprogrammed.
The screen is backlit for low-light situations. Backlighting may be turned on or off under program
control. Contrast is adjustable to compensate for differing lighting conditions and viewing angles.
1.2 What Not to Expect From the GLC24064
Since the display is intended to be used with a controller it does not have any built in text editing
functions. If a stream of ASCII characters are inputed, those characters will be displayed. However, the CR,
LF, backspace, etc., will be ignored. If the application requires these functions, they must be provided by
the software in the controller, which will issue the appropriate positioning commands to the display. The
display does not include a keypad interface.
1.3 mogd.exe
Matrix Orbital has developed an interface program which exercises all the features of the display. The
program can be used to manage font and graphics downloads. "mogd.exe" is provided on Matrix Orbital’s
Cd and website.
To install mogd.exe, follow the following steps;
1. Insert the Matrix Orbital Cd-ROM into the Cd drive
2. Locate the file "mogd.zip", which should be in the “Download” directory
3. Unzip mogd.zip to a temporary directory using a program such as Winzip, Pkzip, etc.
4. Double click on "setup.exe"
5. Follow the instructions on the screen to complete the installation
After the installation is complete there will be a Matrix Orbital entry under “Programs” in the “Start menu”.
Click on this entry to run mogd.exe.
The following information must be entered the first time mogd.exe is run;
Matrix Orbital GLC24064 1

•The port number to be used. (Usually COM1 or COM2)
•The baud rate for the connection. It is best to use 19,200 for initial start-up of the display
•The type of display unit. Set to 240 x 64 for the GLC24064
Once this information is entered the program can be used to control all functions of the display.
1.4 Trying Out the GLC24064
Before setting up the application it is best to test out the display. This is easily done with a PC.
The following is required for testing;
•A 5V power supply (8 to 30 VDC for “Efficient switching supply” (VPT) models)
•A power connector. The type used for 3.5” floppy drives works fine
•A PC with a spare RS-232 port. (Either COM1 or COM2)
•The mogd.exe program
•A 9 or 25 conductor RS-232 serial cable. If using a 25 conductor cable, a 25 to 9 pin adapter will also
be required
The back view of the GLC64064 is shown below for reference.
Figure 1: Rear View of GLC24064
Matrix Orbital GLC24064 2

1.4.1 Here’s what to do:
Figure 2: Connections for Testing
1. Refer to the Figure above for the following steps.
2. Wire the connector to the power supply. On most connectors the RED lead will go to +5V and the
BLACK lead to GND.
NOTES
•Do not connect the GLC24064 to a spare floppy drive power lead in the PC. The
wiring is not correct and the unit will be damaged.
•The Manufacturer’s Warranty becomes void if the unit is subjected to over-voltage
or reversed polarity.
3. Connect the display to the PC using the serial cable and adapter if required.
4. Connect the power connector, ensuring that the +5V goes to V+ as shown in the Figure above. Turn
on the power; the LCD backlight should come on.
5. Use the mogd.exe program to exercise some of the features of the display to make certain everything
works properly.
6. To experiment with typing text; run a PC terminal program, such as Hyperterm. Make certain it’s
configured to use the correct port. Set the baud rate to 19,200.
Once this is complete, try typing some characters on the keyboard. The characters should now appear on the
display screen. Note that CR, backspace, etc., will not have any effect. Text will wrap around to the next
line when the end of a line has been reached.
Matrix Orbital GLC24064 3

1.5 Manual Over-ride
Manual over-ride should only be required in one instance. If for some reason the module is set at a baud
rate which cannot be produced by the host system and all communication to the display is lost, then the user
should follow this simple procedure;
1. Turn off the display
2. Put a jumper on the manual over-ride pins.
3. Power up the display. The baud rate is now set to 19,200.
4. Remove the jumper and change the RS-232 port settings to the desired baud rate.
5. Turn off the display.
6. Power up the display.
Figure 3: Manual over-ride
Refer to the "Set RS-232 port speed", command for acceptable baud rates. This procedure does not
change settings in the memory chip. The procedure uses default settings stored in the main processor, which
allows the user to communicate with the display when all other communications are lost. Once able to
communicate with the display, the user may then change the default settings in the memory chip.
Please note that with the manual over-ride jumper in place, the unit will receive and perform commands
such as turning the backlight on and off. However, it will not output text to the LCD.
1.6 Memory Chip Lock Down
The display uses a memory chip to store speed, start-up screen contrast, fonts, bitmaps and I2C settings.
When everything has been changed to the desired settings and the unit is in a finished product or in the field,
locking down the memory chip so no settings can be changed is desirable. This procedure is only to be done
by knowledgeable people.
WARNING Any damage to the display resulting from user error while
performing this procedure will not be covered under the Manufacturer’s
Warranty.
Matrix Orbital GLC24064 4

Figure 4: Memory Chip Lockdown
To lock down the memory chip simply solder the jumper in the ’red box’ and cut the trace where the ’red
X’ is. This will lock down the memory chip, thereby not allowing anything to be changed inside it until the
track is restored and the solder jumper is removed.
2 Connections
2.1 Power
WARNINGS
•Do not apply any power with reversed polarization.
•Do not apply any voltage other than the specified voltage.
•Do not use any cables other than the cables supplied by Matrix
Orbital, unless the user is aware of the modifications required.
•Do not apply voltage to the DB-9 connector AND power connector
•Do not apply more than +5Vdc to pin 9 on the DB-9 connector.
Refer to the diagram below for this chapter.
Matrix Orbital GLC24064 5

Figure 5: Electrical Connections
Table 1: Connectors & Functions
Connector Function
4 pin Power (Vdc) and I2C communica-
tions or RS-232
DB-9F RS-232 / power
2 pin header GPO header
3x2 header I2C and RS-232 select
2.1.1 Power Connection (4 pin header)
Power is applied via pins 1 and 4.
Power requirement is as follows;
•+5Vdc ±0.25V on standard voltage units
•+7Vdc to +30Vdc with “Wide voltage” and “Efficient switching power” supply (-VPT).
Figure 6: Power Connector
Matrix Orbital GLC24064 6

Table 2: Connector Pinout
Pin 4 Ground
Pin 3 SDA (I2C data) / Rx
Pin 2 SCL (I2C clock) / Tx
Pin 1 Vdc
2.1.2 Five volt Power Cable
If a display module is used in a PC, it becomes tempting to plug a spare power connector into the unit.
Do not do this! Wiring for the PC power connector and that required for the module are different, as shown
in the Figure below.
Figure 7: Wiring for 5 Volt Modules
Matrix Orbital can supply an adapter cable designed for use with the display module when it’s installed
in a PC, if the user would like to modify cable wiring.
Figure 8: Five Volt Power Cable
Simply insert the splitter cable in series with a ’large’ power connector (e.g. one going to a hard drive)
and plug the small connector into the display module. The connector is ’keyed’ and will only fit one way.
Matrix Orbital GLC24064 7

NOTE The connector provided does not allow access to the middle two pins which are
used for I2C communications. If this functionality is required, Matrix Orbital suggests
wiring a suitable connector.
2.1.3 Wide Voltage with Efficient Switching Power Supply (VPT)
Power is applied to the white or brown four pin SIP connector as follows;
Table 3: Connector Pinout
Pin 4 Gnd
Pin 3 SDA (I2C data) / Rx
Pin 2 SCL (I2C clock) / Tx
Pin 1 +7 - 30V DC
If the sole data source is via RS-232, the data input is via the DB-9 connector. In this case pins 2 and 3
are not used.
NOTE Do not use this cable unless the display module has the "Wide voltage range",
option (option V). Use of the 12 volt power cable with 5 volt modules will damage the
module.
The 12 volt power cable is designed for use with wide voltage range display modules mounted in a PC.
Wiring required for the 12 volt power connector is shown in the Figure below.
Figure 9: Wiring for 12 Volt Modules
Matrix Orbital can supply an adapter cable designed for use with the display module when it’s installed
in a PC, if the user would like to modify cable wiring.
Matrix Orbital GLC24064 8

Figure 10: Twelve Volt Power Cable
NOTE The connector provided does not allow access to the middle two pins, which are
used for I2C communications. If this functionality is required, Matrix Orbital suggests a
suitable connector be wired.
2.1.4 Power Connection (DB-9 Connector)
The display can be powered via pin 9 on the DB-9 connector. No matter which voltage option the display
is equipped with, the user may only use +5Vdc through pin 9. Using +5Vdc bypasses any voltage regulator
on the display.
WARNING These modifications must be done. Improper modifica-
tions will damage the display and result in a void Manufacturer’s War-
ranty.
1. Solder the jumper in the ’red square’. It’s located by the DB-9 connector.
Figure 11: Power DB-9
1. Solder the jumper in the ’red square’ as shown in the Figure below.
Matrix Orbital GLC24064 9

Figure 12: Power Jumper DB-9
2.2 Communications
2.2.1 RS-232 Communications and DB-9 Connector pinout
A standard DB-9F is provided for RS-232 communications. Power may also be supplied via this con-
nector if desired. In addition, the user may use the two middle pins of the power connector for serial
communications. The RS-232 connector on the serial cable is wired so that a standard ’straight through’, 9
pin D-sub cable may be used to connect the modules to a standard serial port such as COM ports on PCs.
Note that this device complies with the EIA232 standard in that it uses signal levels from ±12V to ±12V. It
can also operate correctly at TTL (0 to +5V) levels. To use standard RS-232 no modifications are required.
For TTL, please refer to the Table below.
Figure 13: RS-232 Pinout
Matrix Orbital GLC24064 10

Table 4: RS-232 Pinout
Pin Number Direction Description LCD Host
2 Data from LCD Data Out (LCD) Tx Rx
3 Data to LCD Data In (LCD) Rx Tx
5 - Ground gnd gnd
2.2.2 RS-232 Communication through the Power Connector
RS-232 communication can also be achieved through the middle two pins of the power connector.
Figure 14: Power Connector
Table 5: Connector Pinout
Pin 4 Vdc
Pin 3 Tx
Pin 2 Rx
Pin 1 Ground
To allow this, the jumpers must be set as indicated below.
Figure 15: RS-232
Matrix Orbital GLC24064 11

2.2.3 I2C Communications
The display has I2C communications running at 100 Kbps and up to 127 units can exist on a single
communications line. The display I2C communication lines are the two middle pins of the power connector.
These are shared with RS-232 and must be turned on. The default I2C address is 0x50. The I2C data line
operates on 5 volts.
Figure 16: Power Connector
Table 6: Connector Pinout
Pin 4 Ground
Pin 3 SDA (I2C data)
Pin 2 SCL (I2C clock)
Pin 1 Vdc
The display does not work on I2C by default. The modification shown in the Figure below must be
carried out.
Figure 17: I2C
I2C communication runs at 100 Kbps and supports up to 127 units on a single communications line. The
I2C data line operates on 5V CMOS levels.
Matrix Orbital GLC24064 12

2.2.4 ACK
The idea of ACK is to indicate when the data has been received correctly. ACK does not indicate data
incorrectly received. ACK simply fails to indicate when data is correctly received. Clearly, this is of limited
usefulness and even less so with Matrix Orbital modules. Matrix Orbital modules are not capable of failing
to acknowledge an incorrectly received byte in response to that byte’s transition. They are only capable
of failing to acknowledge the bytes following the byte, which were not received. To fully understand the
reasons for this one needs to understand something about how a Matrix Orbital module processes data.
Basically, the reason why a Matrix Orbital module might fail to receive a byte correctly is that it was unable
to process the byte previous before the failed byte was transmitted. Because the module cannot possibly
know that it would be unable to store the byte before the next byte was received, it cannot know to not ACK.
The reason for this situation in deference to situations one might be familiar with (i.e., memory chips, etc)
is that the Matrix Orbital module employs a micro-processor to perform these data storage functions. A
memory chip takes care of these things entirely in hardware subsystems which operate at the same speed as
the transmission themselves.
The display uses a standard Phillips 7bit address as defined by Phillips. However, Matrix Orbital specifies
I2C address in 8bits. The 8th bit, or least significant bit (LSB or Low Order Bit) of the 8bit address is read
/ write bit. If we take a standard Phillips 7bit address of 45hex this would be in binary 1000101 (this is
7bits). Matrix Orbital would describe the Phillips I2C address of 45hex as 8Ahex. The read address would
be 8Bhex.
For more information on Phillips I2C please visit;
http://www.ping.be/~ping0751/i2cfaq/i2cindex.htm
2.3 General Purpose Output
The general purpose output is provided to control relays or other devices via the display. This allows an
external device to be turned on or off using the controller and software commands.
The GPO is meant to be used as a pair. The positive side of the GPO is connected to a power source of
+5Vdc supplied by the module. This connection is via a 240 ohm resistor which limits the maximum current
to 20 mA. The negative side of the GPO is connected to ground.
If the device which is being driven by a GPO requires a relatively high current (such as a relay) and
has an internal resistance of its own greater than 250 ohms, then the 240 ohm resistor may be removed and
replaced with a jumper. This resistor is located directly to the left of the positive pin of the general purpose
output.
NOTE This operation requires soldering. With the resistor removed the GPO does not
have any over current or over / under voltage protection so care must be taken when using
the GPO. For instance, if the external device is a relay it must be fully clamped using a
diode and capacitor to absorb any generated back electro-motive force (EMF).
Matrix Orbital GLC24064 13

Figure 18: Clamping a Relay
3 Displaying Text
This chapter describes the various text-display commands in detail. Before issuing commands to the
GLC24064 please read sections 7.2 and 7.3.
3.1 General
Text is displayed on the GLC24064 using fonts saved in its internal flash memory. The display is supplied
with a 5x7 font installed. If this is suitable, then there is no need to install any other fonts.
3.2 Writing Text to the Display
When the display receives a character, it displays that character at the position currently defined. The next
character sent to the module then advances to the following position on the display. Characters are drawn
using the currently selected font, and only characters defined in the current font are actually processed.
Characters that are not defined by the current font are ignored, and the positioning is not advanced for the
next character.
The position where text is to be displayed is a single pixel location stored in the display’s volatile memory
and maintained internally by the display’s firmware. This position is manipulated by the commands shown
in the following section.
Matrix Orbital GLC24064 14

3.3 Text Commands
In this section commands are identified by their names and decimal values.
3.3.1 Auto Scroll On (254 81)
When auto scrolling is on, it causes the display to shift the entire display’s contents up to make room for
a new line of text when the text reaches the scroll position defined by the "Set font metrics" command in the
display memory (normally, the bottom right character position - default value for the GLC24064 is 64).
3.3.2 Auto Scroll Off (254 82)
When auto scrolling is disabled, text will wrap to the top left corner of the display area. Existing graphics
or text in the display area are not erased before text is placed. When using proportional fonts without auto
scrolling, care should be taken to clear areas where text is being written, particularly when wrapping occurs.
This may be done using the “Draw solid rectangle” command with the color set to white.
3.3.3 Set Text Insertion Point (254 71 [col] [row])
This command sets the insertion point to the [column] and [row] specified. The insertion point is posi-
tioned using the base size of the current font (this command does not position the insertion point at a specific
pixel). The pixel column used is determined by multiplying the width of the widest character in the font
by [column]. The pixel row used is determined by multiplying the height of the font by [row + interline
spacing]. If precise pixel-based text positioning is required, see "Set text insertion point - pixel values",
below.
3.3.4 Set Current Text Insertion Point to top Left (254 72)
This command moves the text insertion point to the top left of the display area, based on the metrics of
the current font. Refer to the "Set font metrics" command below for more details.
3.3.5 Set Text Insertion Point Using Pixel Values (254 121 [x][y])
This command sets the next position for text placement to an individual pixel location. The coordinate
([x position],[y position]) defines a pixel on the screen where the top left corner of the screen is defined as
(0,0). This pixel location will be used as the top left corner of the next character of text which is sent to the
module without any regard to ’font metrics’ like character spacing or line spacing.
Matrix Orbital GLC24064 15

3.3.6 Set Current Font (254 49 [font ID])
This command instructs the display to use the font specified by [font identifier] as the default font. The
value specified should refer to a font already present in the display’s memory.
NOTE The font ID is established when the font is saved to the display, normally using
the mogd.exe program. The installed 5x7 font ID is 0x01, unless changed by user.
3.3.7 Set Font Metrics (254 50 [metrics])
Where [metrics] = [left margin][top margin][x space][y space][scroll row]
This command defines the metrics of a font already present in the display’s memory.
[left margin] specifies the first pixel column to use for the first character in a row. In some instances,
a font may not evenly fit on the screen, and dividing the extra space between the margins will improve the
overall appearance of the font. [top margin] specifies the top pixel row to begin drawing the first row of
text on the display area. [x space] specifies the number of pixels to place between characters (i.e. character
spacing). [y space] specifies the number of pixels to place between rows of text (i.e. line spacing). [scroll
row] specifies the pixel row where scrolling should start (or, if auto scrolling is off, where wrapping should
occur). Typically, this value should be set to the first pixel row immediately below the last row of text that
will fit the display.
4 Displaying Graphics
This chapter describes the various graphics-display commands in detail. Uploading a graphic to position
1 will result in that bitmap being displayed when the unit is powered on.
4.1 General
Since the display is a bit-mapped device, it may be used to display graphics. Graphic images may be
created by means of a pixel oriented graphics program, saved as bitmaps, and loaded into the display using
the mogd.exe program. Images may be saved in the display’s memory and displayed upon command, or they
may be downloaded ’on the fly’ (in-line) during display operation.
NOTE ’saved’ and ’on the fly’ graphics images are processed differently. These differ-
ences must be taken into account when processing graphics.
Saved bitmaps use each byte (8 bits) to represent a vertical column of 8 pixels. The next byte represents the
next column to the right. If the graphic is ’taller’ than 8 pixels, the LSB of the next data byte will be the next
pixel. Orientation is top to bottom - LSB to MSB. Pixels / bits are ’packed’, meaning; if the height of the
graphic is not an even multiple of 8, the leftover bits go on the next X column to the right, etc.
Matrix Orbital GLC24064 16