Matrix Orbital LK204-25 datasheet: pdf
Contents
1. Note Custom characters will be erased if any of the initialize bar graph commands are issued 5 1 7 Initialize large digits 254 110 This command defines the 8 special user characters to be blocks suitable for use in drawing large digits Any previously existing definitions will be lost Once this command has been issued any number of large characters may be placed until the characters are redefined by another command LK204 25 rev I 20 5 1 8 Place large digit 254 35 col digit This command allows the large digits to be drawn on the LCD screen Numbers of almost full display height may be placed along side regular text on four row displays The column number has a maximum value which is less than the display width because the digits are all three columns wide Before using this command the Initialize Large Digits command must be issued to define the blocks necessary to make up the digits If regular text and large digits are mixed on one screen the user should always set the display cursor position before placing regular text because the creation of a large digit will leave the cursor position to the bottom right of the large digit and not at the last regular text write position col can have values from 0x01 to 0x12 1 to 18 digit has values from 0x00 to 0x09 0 to 9 LK204 25 rev 1 21 6 Miscellaneous Commands The commands listed in this chapter don t readily fit in any of the other categories or are used in more2. Resolution 1 0 6554 ms time is a numeric multiplier 7 6 Bar Graphs and Special Characters The commands in this section are used to define and display bar graphs and special characters Table 7 3 Bar Graph and Special Character Commands Initialize thick vertical bar graph Initializes the user character set to make wide vertical bar graphs Initialize thin vertical Initializes the user character set to make narrow vertical bar bar graph Initialize horizontal bar graph Define custom character Draw vertical bar graph Draw horizontal bar graph Initialize large digits Place large digits LK204 25 rev 1 FE 4E c 8 bytes 254 78 c 8 bytes 254 N c 8 bytes FE 3D col length 254 61 col length 254 col length FE 7C c r d length 254 124 clfr d flength 254 e r d length FE 23 col digit 254 23 col digit 254 col digit graphs Initializes the user character set to make horizontal bar graphs Defines one of 8 custom user characters Character number is c between 0x00 and 0x07 The 8 bytes are described in section 5 1 6 Draws a vertical bar graph at column col of length length Length is measured in pixels Ox00 to 0x14 User must first use the v or e command to initialize characters Draws a horizontal bar graph starting at column c on row r with direction d 0 is right 1 is left of length length Length is measured in
3. LK204 25 User Manual LK204 25 rev 1 1 Table of Contents la MUD OGUG de D 4 EI ee 4 E Witt tit OCS IN OLD iaa idas os 4 AA e e O O A A E AE ESEE E A A 4 CAS O EE 4 LS TAS CVG VO LR EE 5 tte outa A A 6 OLAS AO alas 6 25 e Et en EE 7 21 Connector EH 7 2 1 1 Power and I C Connections c ccccccccssecsscessecessccsceccecsvsceevsccacsavscesvsceacsevacesvaceevsevacevaceevess 7 2 1 2 RS 232 Communications 24 3 E E DEER 10 2 2 General Purp se EE 111 3 DISpiaving a KC GE 13 EE 13 3 2 RER EE ag Character PO dis 13 SAS NWD Text tO Eeer 14 ls A A A 14 SL Auto live WEA O 2 AOS od 14 342 AO Me rap LIADO ds 14 A A A AN 14 A A EE 14 3 4 5 Set cursor position 254 71 column TOW saas E ER 14 oo ona 1 D 14 3 Ac Turon underline Cursor 25414 EE 14 3 4 8 Turion underline EN AA E E 15 34 9 Turion block blinkin KEE 15 3 4 10 Turn off block blinking cursor 254 Sat 15 SA Munson lei 25476 EE 15 SE E eet ELSE TATA E 15 d Keypad Interface ninia 16 GN EE 16 42 A a a a E 16 eA EE 17 2 A 17 ASe AA 17 4 5 1 Auto repeat mode on 254 126 fmodelt renerne rn ere enker nere eres r renee 17 A 522 Auto EN mode OH 25490 ee ee ege 18 4 5 3 Auto transmit keypresses on 254 ot 18 4 5 4 Auto transmit keypresses off 254 e EEN 18 453 Clear Key DULCE E EEN 18 AO POW Keypad e WEE 18 4 5 7 Set debounce time 254 85 Tome 18 LK204 25 rev 1 2 5 Bar Graphs and Special CharacterS oncoccoccccnccncoonoccccnccncnn
4. row dir length Draws a horizontal bar graph in row starting at column with a length of length pixels row may have a value of 0x01 or 0x02 column may range from 0x01 to 0x14 and length may be from 0x00 to 0x64 0 to 100 if the graph can extend the full width of the screen Each column is 5 pixels wide spaces between the columns don t count dir specifies the direction 0x00 goes from left to right 0x01 goes from right to left 5 1 6 Define custom character 254 78 c 8 bytes The LK204 25 allows up to 8 user defined custom characters These characters occupy the first 8 0x00 to 0x07 places in the character set see Figure 3 1 LK204 25 rev 1 19 Custom characters occupy a 5 x 8 pixel matrix Built in characters are 5 x 7 the bottom row of pixels is normally reserved for the underline cursor The underline cursor should be turned off if the bottom row of pixels forms part of a custom character The characters are defined by issuing the command 254 78 c followed by 8 bytes to define the character c is the character number 0x00 to 0x07 The 8 bytes are mapped as shown below e ET SEECGOR ec A 1 bit indicates an on black pixel a 0 bit indicates an off clear pixel Once defined a character is displayed simply by issuing a value 0x00 to 0x07 corresponding to the character number The character will be laid out as follows pepe pe pepe AE HOO DAAE HOALE EJEJEJEJES Cursor Line
5. 254 96 This command turns off auto repeat mode 4 5 3 Auto transmit keypresses on 254 65 In this mode all keypresses are sent immediately to the host system without the use of the poll keypad command This is the default mode on power up 4 5 4 Auto transmit keypresses off 254 79 In this mode up to 10 keypresses are buffered until the unit 1s polled by the host system via the poll keypad command Issuing this command places the unit in polled mode 4 5 5 Clear key buffer 254 69 This command clears any unread keypresses In a menung application if the user presses a key which changes the menu context any following key presses may be inaccurate and can be cleared out of the buffer between menu changes to prevent jumping around the menu tree It may also be used to in effect reset the keypad in case the host application resets for whatever reason 4 5 6 Poll keypad 254 38 This command returns any unbuffered keypresses via the RS 232 interface The host system must be set up to receive the key codes When the LK204 25 receives this command it will immediately return any unbuffered keypresses which may have not been read already If there is more than one keypress buffered then the high order bit MSB of this returned keycode will be set 1 If this is the only buffered keypress then the MSB will be reset 0 If there are no buffered keypresses then the returned code will be 0x00 Please note to make use of this command
6. PC Figure 2 4 Five volt Power Cable 2 1 1 2 Wide Voltage Range Modules Note Do not use this cable unless your 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 LK204 25 rev 1 8 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 Figure 2 5 below TN 5 V GND PC wiring NN 12 V mm 12 V mm HENNE i TE Se Display module wiring Figure 2 5 Wiring for 12 volt modules If you don t want to modify cable wiring yourself Matrix Orbital can supply an adapter cable designed to use with the display module when it s installed in a PC The cable is wired as shown in Figure 2 6 below Figure 2 6 Twelve volt power cable 2 1 2 RS 232 Communications A standard DB 9F is provided for RS 232 communications Power may also be supplied via this connector if desired See Figure 2 7 for pin connections LCD Module Host System 1 T F Optional 5 Volt Power Supply Figure 2 7 RS 232 and power connector The RS 232 connector on the PC cable is wired so that a standard straight through 9 pin D sub cable may be used to connect the module to a standard serial port such as COM ports on PCs Note that this device complies with the EIA232 standard in
7. rev I 25 254 G col row Send cursor home Underline cursor on Underline cursor off Block cursor on Block cursor off Cursor left Cursor right 7 5 Keypad Interface Commands Table 7 2 Keypad Interface Commands Auto repeat mode on FE 7E 0x00 0x01 254 126 0 1 254 0 1 Auto repeat mode off Auto transmit key presses on Auto transmit key presses off Clear key buffer LK204 25 rev 1 26 this and all commands This command moves the cursor to the top left of the display area Turns on the underline cursor Turns off the underline cursor Turns on the blinking block cursor Turns off the blinking block cursor Moves the cursor one position to the left If the cursor is already at the beginning of a line it will move to the end of the other line Moves the cursor one position to the right If the cursor is already at the end of a line it will move to the beginning of the other line Applies to keypad only 0x00 200 ms typematic 0x01 key down key up codes sent Applies to keypad only Sets auto transmit mode for keypad Key presses are transmitted to host without polling Up to 10 key presses buffered until polled Clear unread key presses eg Je Je Returns buffered key presses to application Returns 0x00 if no key presses High order bit Poll keypad set unless this is the last only key press Set debounce time FE 55 time 254 85 time 254 U time
8. that it uses signal levels from 3V to 12V It will not operate correctly at TTL 0 to 5V levels LK204 25 rev 1 9 Pin number Sege Deserinon from LCD module Data Out O sam The power connector on the PC cable is wired as shown in Figure 2 7 2 1 3 Configuring RS 232 and TC RS 232 baud rate and DC address are configured by means of jumpers Figure 2 8 RS 232 jumpers The module is supplied with jumpers J1 and J2 installed which gives an RS 232 baud rate of 19200 and an I C address of 0x5C RS 232 port JO J1 J2 control baud rate RS 232 format is 8N1 8 bits no parity one stop bit PC port JO J1 J2 J3 sets slave peripheral address Baud Rate Slave Address 1200 psn fou fou ot in fos ou in four mei fu fou in in oa in on ot 9600 a fot in on in MIO faa fm fw far 19200 psx fu fn Peon on fot fan far C on fn fa far fm on fn E far 2400 am fn fa fn f o Tr fr E LK204 25 rev I 10 2 2 General Purpose Outputs The LK204 25 has six general purpose outputs These are provided to control relays or other electronic devices This allows external devices to be turned on or off using your PC or controller and software commands See sections 6 1 5 and 6 1 6 for the command syntax Each output is wired as shown in Figure 2 9 The terminal is connected directly to the module positive supply the terminal is connected through a 240 ohm current limiting resist
9. the Auto Transmit Keypress mode should be off 4 5 7 Set debounce time 254 85 time time is in increments of 6 554 milliseconds This command sets the time between key press and key read All key types with the exception of latched piezo switches will bounce for a varying time depending on their physical characteristics The default debounce time for the module is about 52 mS which is adequate for most membrane keypads This time equates to a setting of 8 using this command as there is a debounce time resolution of 6 554 milliseconds LK204 25 rev 1 18 5 Bar Graphs and Special Characters The LK204 25 includes the ability to draw bar graphs either horizontal or vertical and allows users to define up to eight special characters Before issuing commands to the LK204 25 please read sections 7 2 and 7 3 Eight characters ASCII values 0x00 to 0x07 are set aside for use with bar graphs user defined characters and big numbers Since the same 8 characters are used for each function the functions may not be used simultaneously The characters may be defined or redefined at any time by issuing the commands shown in this section Once defined they may be used either by means of the bar graph commands or by simply issuing one of the ASCII values 0x00 to 0x07 which is not prefixed by the command byte 254 5 1 Command List 5 1 1 Initialize wide vertical bar graph 254 118 This command defines the 8 special user charac
10. 2 second delay After this delay key codes will be sent via the RS 232 interface at a rate of about 5 codes per second This mode has no effect if polling or if using the PC interface 2 Key down Key up codes This mode may be used when the typematic parameters of the Resend Key code mode are unacceptable or if the unit is being operated in polled mode The host system detects the press of a key and simulates an auto repeat inside the host system until the key release is detected In this mode when a key is held down the key code is transmitted immediately and no other codes will be sent until the key is released On the release of the key the key release code transmitted will be a value equal to the key down code plus 20 hex For example the key code associated with key P 0x50 is pressed the release code is p 0x70 In RS 232 polled mode see 4 5 4 below or via the PC interface the key down key up codes are used however the user should be careful of timing details If the poll rate 1s slower than the simulated auto repeat it is possible that polling for a key up code will be delayed long enough for an unwanted key repeat to be generated see Figure 4 2 LK204 25 rev 1 17 Polls Key up Key down auto repeat clock valid key strane unwanted auto repeat before key up after key up Figure 4 2 Poll timing 4 5 2 Auto repeat mode off
11. C Clears the display and puts the cursor at the top left BS 0x08 Moves the cursor one position to the left and clears that position Note These command characters are not guaranteed to work on other Matrix Orbital display modules If you want your code to be portable use the appropriate commands listed later in the manual instead If you want to exercise some of the other features of the LK204 25 you ll need to write a program in any convenient language such as Basic or C to issue the required command strings Most terminal programs are unable to issue the OxFE character needed as a command prefix You probably won t need to do this at the initial testing stage If you ve reached this point and operation is normal you can be confident that your LK204 25 works properly 1 6 Trying out a Keypad Since a number of different keypad types can be connected to the LK204 25 the results you get may be a little unpredictable At this point all we need to do is make sure that your keypad and interface work and possibly generate an ASCII map for your programming needs The keypad interface on the LK204 25 converts a row column connection to an ASCII character By default a keypress is transmitted as serial data immediately Keypad buffering can be selected using the appropriate commands 1 6 1 Here s what to do 1 Your PC should be running a terminal program such as Hyperterm as in the previous section 2 With the LK204 25 connected to
12. Short for Inter 1C a type of bus designed by Philips Semiconductors in the early 1980s which is used to connect integrated circuits ICs PC is a multi master bus which means that multiple chips can be connected to the same bus and each one can act as a master by initiating a data transfer LK204 25 rev 1 31 Interface A means by which two systems interact Liquid Crystal Display e eg Type This refers to the model number of the module pg The smallest individually controllable element of a display Pre Generated Pre determined fonts which can be downloaded into graphic liquid crystal Fonts displays Primitive A low level object or operation from which higher level more complex objects and operations can be constructed In graphics primitives are basic elements such as lines curves and polygons which you can combine to create more complex graphical images Short for recommended standard 232C a standard interface approved by the Electronic Industries Association EIA for connecting serial devices means that once the screen is full each new line appears at the bottom edge of the screen and all other lines move up one position Serial Number A number that is one of a series and is used for identification of the module Serial Port A port or interface that can be used for serial communication in which only 1 bit is transmitted at a time Version This refers to the firmware revision number of the module Numbe
13. ay be turned on or off independently The cursor is off by default 3 4 10 Turn off block blinking cursor 254 84 Turns off the blinking block cursor Does not affect the underline cursor 3 4 11 Cursor left 254 76 Moves the cursor one position to the left but does not erase any character that may be in that position Note that this command moves the text insertion point even if the cursor is turned off Note A destructive backspace which erases the character to the left of the original position may be done by issuing the following sequence cursor left space cursor left 3 4 12 Cursor right 254 77 Moves the cursor one position to the right but does not erase any character that may be in that position Note that this command moves the text insertion point even if the cursor 1s turned off LK204 25 rev 1 15 4 Keypad Interface This chapter describes the keypad interface and associated commands in detail 4 1 General The LK204 25 keypad interface processes the keypad row column matrix into a serial RS 232 or PC data byte stream Aside from this processing the keypad has no effect on the LK204 25 display If you need to send keystrokes to the display they must be routed through your controller 4 2 Connections 10 3 un 999 3 m Li dl ep Figure 4 1 Keypad Connector The connector is not keyed so your keypad will probably plug in either of two ways The LK204 25 will not be damaged
14. by reversing the connector but your keypad will generate a different ASCII character mapping for each position If your connector has fewer than 10 pins it should be centered on the LK204 25 connector The returned key codes are as follows but note that your keypad may be laid out in a different pattern If this is the case you will need to interpret the key codes differently The diagram 1 shows the logical layout row 1 column 1 in upper left The connector for the keypad is a 10 pin 0 1 spacing male header Pin 1 is indicated in Figure 2 1 Pins 1 through 5 are columns and pins 6 through 10 are rows The keypad is scanned whenever a key is pressed there is no continuous key scan This means that key presses are dealt with immediately without any appreciable latency This also prevents electrical noise which is often caused by continuous key scans Columns Note The keypad connector must be wired with columns on one side and rows on the other side of the center of the connector If your keypad isn t wired this way you will need to make an adapter or rewire the connector to meet this requirement LK204 25 rev 1 16 4 3 EC Interface The keypad is read by PC master read In short this means that a read of the module will always return the first unread key press A read 1s initiated by writing to the module with its base address plus 1 then clocking the module s return byte after the module releases the SDA line Much more detail on t
15. er see section 2 1 1 1 2 1 1 Power and FC Connections Power is applied via pins 1 and 4 as shown in Figure 2 1 Power requirement is 5 VDC 0 25V Power may also be supplied via the RS 232 connector as described in the next section Warning 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 you are aware of the modifications required Do not apply voltage to the DB 9 connector AND power connector LK204 25 rev 1 7 Connector pinout is as follows Figure 2 2 Power connector Pin 1 5 0 VDC 7 to 15 VDC with wide voltage option Pin2 SCL YC clock Pin3 SDA PC data Pin4 Ground 2 1 1 1 Five Volt Modules If the LK204 25 is used in a PC it is tempting to plug a spare power connector into the unit Don t do this Wiring for the PC power connector and that required for the LK204 25 are different as shown in Figure 2 3 below RN 5 V m 12 V B 5 V Display module wirin GND Play g Figure 2 3 Power Connector wiring differences If you don t want to modify cable wiring yourself Matrix Orbital can supply an adapter cable designed to use with the LK204 25 when it s installed in a PC The cable is wired as shown in Figure 2 4 below Note that this cable does not provide connections for
16. ess backlighting source consists of a fluorescent tube powered by a high voltage A C source Configuration The way a system is set up or the assortment of components that make up the system Configuration can refer to either hardware or software or the combination of both Contrast The ratio of luminance between the light state of the display to the dark state of the display Controller The microcontroller or PC used to control the Matrix Orbital display unit DB 9 The designation of a connector used in the RS232 interface 9 pin connector Software programs or data that has been written onto read only memory ROM Firmware is a combination of software and hardware ROMs PROMs and EPROMs and flash EEPROMs that have data or programs recorded on them are firmware Bitmap U A design for a set of characters A font is the combination of typeface and other qualities such as size pitch and spacing A definition of where font is to be placed such as margins and spacing between characters and lines Refers to the base 16 number system which consists of 16 unique symbols the numbers 0 to 9 and the letters A to F For example the decimal number 15 is represented as F in the hexadecimal numbering system The hexadecimal system is useful because it can represent every byte 8 bits as two consecutive hexadecimal digits It is easier for humans to read hexadecimal numbers than binary numbers Hexadecimal S CH
17. gpo is 1 to 6 ON means that the output 1s pulled low ground via 240 ohms LK204 25 rev I 22 6 1 7 Read module type This command does not work on the LK204 25 LK202 25 0x08 LK404 55 Ox0A VFD2021 0x0B VFD4021 0x0D VK202 25 0x0E GLC12232 0x10 GLK12864 25 0x14 GLK24064 25 0x15 GLK128128 25 0x21 GLK12232 25 0x22 LK404 AT 0x31 VFD1621 0x32 LK402 12 0x33 LK162 12 0x34 LK204 25PC 0x35 GLC12864 0x11 GLC128128 0x12 GLC24064 0x13 6 1 8 Read Version Number 254 54 This command will return the firmware version number of the LK204 25 LK204 25 rev 1 23 7 Appendix Command Summary 7 1 General The operation of the LK204 25 is controlled by a simple and consistent command set Commands control text display graphics display keypad interface miscellaneous operating parameters This chapter includes summary tables of all commands Individual commands are discussed in detail in Chapters 3 to 5 in the same sequence as in the following tables 7 2 Issuing Commands Commands are issued to the LK204 25 by the controller In a test setup commands can be issued to the LK204 25 by means of a BASIC program using the chr function In the tables below we ve shown commands in hex ASCII and decimal form All commands begin with the prefix character OxFE 254 decimal These commands are issued on the serial communications link PC or RS 232 at the currently defined baud rate For exam
18. his basic PC function can be found in the PC specification by Philips A good reference is also available at http www ping be ping075 1 12cfaq i2cindex htm The module contains a ten key press buffer so that it can be polled for key presses at an infrequent rate every 500 to 1000 mS is typical All returned key presses indicate the presence or absence of additional logged key presses by the most significant bit MSB bit 7 If the user has pressed two keys since the last poll of the keypad interface the first read will return the key code with bit 7 set and the second read will return the key code with bit 7 clear The application must take into account this bit to keep up with user key presses If there are no keypresses detected the module will return zero 0x00 4 4 RS 232 Interface By default on any press of a key the module will immediately send out the key code at the selected baud rate This behavior can be modified using commands found in the next section 4 5 Keypad Commands Before issuing commands to the LK204 25 please read sections 7 2 and 7 3 4 5 1 Auto repeat mode on 254 126 mode mode 0x00 gives Resend Key Code mode mode 0x01 gives Key down Key up code mode Two Modes of auto repeat are available and are set via the same command 1 Resend Key Code This mode is similar to the action of a keyboard on a PC In this mode when a key is held down the key code is transmitted immediately followed by a 1
19. ical Specifications Supply Voltage 4 75 5 25 Vdc optional 8 15 VDC Supply Current 9 mA typical Supply Backlight Current 115 mA typical Character Size 3 20 x 5 55 mm XxY not including underline LK204 25 rev I 29 Max depth 21 0mm CT without connectors 3 i 255mrm Figure 8 1 Physical Layout 8 2 Options LK204 25 rev I 30 9 Appendix Glossary ASCII American Standard Code for Information Interchange A 7 bit binary code representing the english alphabet decimal numbers and common punctuation marks Also includes control characters such as carriage return or end of text An 8 bit superset of the standard ASCII codes is often used today to include foreign characters and other symbols These supersets are often called extended ASCII character sets Backlight A backlit display is illuminated from behind to provide nighttime and improved daytime readability Baud Rate The data and signaling bit transmission rate of an RS232 device Binary A number written using binary notation which only uses zeros and ones Number The smallest unit of information a computer can work with Each bit is either 0 or 1 Binary digit A representation consisting of rows and columns of dots of a graphics image in computer memory The value of each dot whether it is filled in or not is stored in one or more bits of data yte A grouping of eight binary bits CCFL Cold Cathode Fluorescent Lamp A high brightn
20. igure 3 1 Character Set LK204 25 rev I 13 In addition to the built in characters users may define up to 8 special characters which once defined occupy positions 0x00 to 0x07 in the above chart The LK204 25 does not have provision to download other fonts 3 3 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 built in font and only characters defined in the font are actually displayed Characters that are not defined by the built in font print as a space 1 e the cursor is advanced for the next character The position where text is to be inserted is a character location stored in the LK204 25 s volatile memory and maintained internally by the LK204 25 s firmware This position is manipulated by the commands shown in the following section 3 4 Text Commands In this section commands are identified by their names and decimal values Hex and ASCII equivalents are given in the summary Table 7 1 Before issuing commands to the LK204 25 please read sections 7 2 and 7 3 3 4 1 Auto line wrap on 254 67 Enables automatic line wrapping Note that this is not word wrapping and wraps may occur in the middle of a word 3 4 2 Auto line wrap off 254 68 Disables automatic line wrapping Characters beyond the end of a line will be lo
21. nnector to the power supply On most connectors the RED lead will go to 5V and the BLACK lead to GND See Section 2 1 1 for details Note The manufacturer s warranty is void if the unit is subjected to over voltage or reversed polarity 3 Connect the LK204 25 to the PC using the serial cable and adapter if required Make sure the RS 232 cable includes the required ground lead There must be no voltage differential between the RS 232 ground and the power supply ground 4 Connect the power connector making sure that the 5V goes to V as shown in Figure 2 2 Turn on the power the LCD backlight should come on with a blinking cursor in the top left corner Now you re ready to try it out 1 5 Trying Out your LK204 25 The unit is connected to power and the PC and the backlight is on you will also see a blinking cursor in the top left corner You re ready to make sure it s working properly To experiment with typing text run a PC terminal program such as Hyperterm Make sure it s configured to use the correct port Set the baud rate to 19 200 If you type characters on the keyboard they should now appear on the LK204 25 screen Text will wrap around to the next line when you reach the end of a line A few common ASCII control characters work as follows Character Hex value Function CR 0x0D Moves cursor to beginning of the current line LF 0x0A Moves cursor to the beginning of the next or previous line LK204 25 rev I 5 FF 0x0
22. of sources A few examples will do here The letter A has a value of 65 decimal or 41 hex The letter a has a value of 97 decimal or 61 hex The number 0 has a value of 48 decimal or 30 hex The number 9 has a value of 57 decimal or 39 hex This gives rise to the possibility of confusion when parameters are being set on the LK204 25 For example the GPO ON and OFF commands use a number to indicate which GPO is being controlled We re told that acceptable values are 0 to 6 All such parameters must use numeric values i e the actual byte values If we send the ASCII number 0 by mistake it will actually give the value 48 decimal 30 hex to the parameter which 1s wrong In the tables given in the following sections ASCII characters are shown as A with single quotes 7 4 Text Commands See Chapter 3 for command descriptions Syntax in the tables below is given in hex decimal and decimal with ASCII in that order one per line Table 7 1 Text Commands comment Jee Ja Jee Auto line wrap on Enables line wrapping not word wrap Auto line wrap off Disables line wrapping Auto scroll on Enables scroll at bottom of screen Text will push display up one line to make room for new line Auto scroll off Disables auto scroll Text will wrap to top left and overwrite existing text Set cursor position FE 47 col row n a Moves cursor to the specified column and row 254 71 coll row The cursor marks the text insertion point in LK204 25
23. or and the electronic switch to ground GPO 1 GPO 2 GPO 3 GPO 4 GPO S GPO b Figure 2 9 General Purpose Outputs Maximum allowable current is 20 mA which is enforced by the current limiting resistor If the device being switched has a resistance of 240 ohms or more the corresponding resistor may be shorted Solder a small jumper wire wirewrap wire 1s good from the feedthrough hole to the corresponding negative pin for the GPO in question LK204 25 rev 1 11 q i umperwire Figure 2 10 Bypassing 240 ohm resistor Note The GPOs do not have any over current or over under voltage protection so care must be taken when using them 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 GPO 10 100 uF Re lay coll Figure 2 11 Clamping a Relay LK204 25 rev I 12 3 Displaying Text This chapter describes the various text display commands in detail A quick reference summary of all text commands is found in section 7 4 3 1 General Text is displayed on the LK204 25 using the built in 5 x 7 dot matrix font plus up to 8 user defined characters 3 2 The Built In Character Font The LK204 25 includes a built in 5 x 7 dot matrix font with the full range of ASCII characters plus a variety of extended characters as shown in Figure 3 1 O O O ET TE foo LH feo pes EES es js F
24. pixels 0x00 to 0x64 if starting in column 1 User must first use the h command to initialize characters Initializes the user character set to make large digits Place large digit number digit in column col of the display Cursor moves to bottom right of large digit digit is 0x00 to 0x09 col is 0x01 to 0x12 i e 1 to 18 decimal 27 7 7 Miscellaneous Commands Table 7 4 Miscellaneous Commands comment mex CT e ooo Clear display Clears screen of text and graphics places text cursor at top left Set contrast FE 50 contrast Sets display contrast Compensates for 254 80 contrast viewing angle Contrast is a value between 0 254 P contrast and 255 hex 0 to FF Larger darker Backlight on FE 42 minutes Backlight will stay on for minutes If 254 66 minutes minutes 0 backlight will stay on 254 B minutes permanently Backlight off Turns off backlight General purpose FE 56 gpo Turns a general purpose output OFF gpo output off 254 86 gpo may be from 1 to 6 See section 2 2 for further 254 V gpo details General purpose FE 57 gpo Turns a general purpose output ON gpo output on 254 87 gpo may be from 1 to 6 See section 2 2 for further 254 W gpo details Read Version Reads the firmware version number of the Number module LK204 25 rev I 28 8 Appendix Specifications and Options 8 1 Specifications OT sendes Tenportne nora romper Electr
25. ple using BASIC in a test setup you could issue the command to clear the screen on the LK204 25 by including the line PRINT 1 chr 254 chr 88 in your BASIC program Or with C you could using Zcomm serial library ZCommi1 gt WriteCommByte 0xfe ZComml1 gt WriteCommByte X 7 3 On Numbers Like all computerized devices the LK204 25 operates with commands and values in the form of binary numbers These binary numbers are arranged in 8 digit 1 e 8 bit groups called bytes The decimal value of a byte may have any value from 0 to 255 Bytes are usually specified in either decimal or hexadecimal base 16 form for convenience since binary numbers are confusing to deal with directly Hexadecimal hex numbers are particularly convenient because exactly two hexadecimal digits make up one byte each hex digit representing 4 binary digits 4 bits as shown here LK204 25 rev 1 24 Based on the table the byte 01001011 can be represented in hex as 4B which is usually written as any of 4Bh 4BH 4B hex or 0x4B The numbers can also be expressed in decimal form if preferred 7 3 1 ASCII Characters Since computers deal internally with numbers only but externally with both letters and numbers several schemes were developed to map written characters to numeric values One such scheme has become universal the American Standard Code for Information Interchange or ASCH ASCII tables are readily available from a number
26. puts allow the controller to switch up to six electronic or electro mechanical devices by issuing commands to the display unit These can be used for controlling LEDs relays etc 1 2 What it Does Not Do The LK204 25 does not include bitmap graphics capability except that permitted by defining special characters 1 3 Keypad Interface The keypad interface takes row column input and converts it to ASCII characters which are delivered out the RS 232 or TC port to the associated controller Note that the keypad is not used to directly control any aspect of the operation of the LK204 25 which acts simply as a matrix to serial converter If you want to use the keypad to control the LK204 25 display you must program your controller accordingly 1 4 Setup for Testing Before setting up your application you may want to try out the LK204 25 This is easily done with a PC Here s what you ll need LK204 25 rev 1 4 power cable with a 4 pin connector same connector as used to connect 3 5 inch floppy drive Do not connect the LK204 25 to an unmodified spare power connector in a PC To modify such a cable see section 2 1 1 power supply A PC with a spare RS 232 port COM1 or COM2 A9or 25 pin RS 232 serial cable If you use a 25 conductor cable you ll also need a 9 to 25 pin adapter 54 power Ai o Figure 1 1 Connections for Testing 1 Refer to the diagram above and Figure 2 1 for the following steps 2 Wire the co
27. r Volatile Temporary memory Once the power supply is turned off volatile memory is Memory then erased ae To view consecutive lines of data on the display screen The term scroll LK204 25 rev 1 32
28. ronrnnnonncnncnncnnronrnanrnnrnnrnarnnnennnns 19 OM Oh e 19 5 1 1 Initialize wide vertical bar graph 254 118 coi acia 19 5 1 2 Initialize narrow vertical bar oraph 154 115 eessen 19 5 1 3 Draw vertical bar graph 254 61 column hehe 19 5 1 4 Initialize horizontal bar eraph 214 104 joeren RA A E 19 5 1 5 Draw horizontal bar graph 254 124 column row dir length 19 5 1 6 Define custom Character 234 78 c SDE iii A ds 19 SL 0 tal Ls O EE 19 1 7 Place late dis 234 30 COM Ee 21 6 MISCEIIANCOUS GEES 22 6 EE EE 22 6 TL CE DS dd le 22 6 1 2 Set contrast 254 80 contrast 22 6 1 3 Backlight On 23400 minutes EE 22 EN di 70 EE 22 6 1 5 General purpose output off 254 Sploenoiit 22 6 1 6 General purpose output on O 4S leno it nes enker renerne ere rr erreee 22 7 Appendix Command Summary coccoccccccnncnncncccnccnnonanoncnnnnnncnnrnnrnnrnnrnnrrnnrnnrnnrnnrrnnrnnrnarnanennnn 24 RG a cs EE 24 92 ia o AAA EA 24 EE 24 E NEE E EE 25 A E AEA T TAR 25 F3 Keypad Intertace Command E 26 1 0 Bar Graphs and Special Characters EE 27 ENEE Ee E A risser ae ee t N aO 28 8 Appendix Specifications and Options NENNEN RRNR ENER EN NENNEN ENNEN ENNEN NRERER ENNEN 29 Sal PVC CI HE HO Sereia enn NEN E A A Pele on DEN Dead DN tI tlh EAD 29 ON lie 30 9 Appendix Glossary EE 31 LK204 25 rev I 3 1 Introduction Your LK204 25 has the following features 20 column by 4 line
29. st 3 4 3 Auto scroll on 254 81 When auto scrolling is on it causes the LK204 25 to shift the entire display s contents up to make room for a new line of text when the text reaches the scroll position the bottom right character position 3 4 4 Auto scroll off 254 82 When auto scrolling is disabled text will wrap to the top left corner of the display area Existing text in the display area is not erased before new text is placed A series of spaces followed by a Cursor Home command may be used to erase the top line of text 3 4 5 Set cursor position 254 71 column row This command sets the cursor position text insertion point to the column and row specified Columns have values from 1 to 20 0x01 to 0x14 and rows have values of 1 and 2 0x01 and 0x02 3 4 6 Send cursor home 254 72 This command moves the cursor position text insertion point to the top left of the display area 3 4 7 Turn on underline cursor 254 74 Turns on the underline cursor The cursor shows the current text insertion point Both underline and blinking cursors may be turned on or off independently The cursor 1s off by default LK204 25 rev I 14 3 4 8 Turn off underline cursor 254 75 Turns off the underline cursor Does not affect the blinking block cursor 3 4 9 Turn on block blinking cursor 254 83 Turns on the blinking block cursor The cursor shows the current text insertion point Both blinking and underline cursors m
30. ters to be blocks suitable for use in drawing wide 5 pixel vertical bar graphs Any previously existing definitions will be lost Once this command has been issued any number of vertical bar graphs may be drawn unless the characters are redefined by another command 5 1 2 Initialize narrow vertical bar graph 154 115 This command defines the 8 special user characters to be blocks suitable for use in drawing narrow 2 pixel vertical bar graphs Any previously existing definitions will be lost Once this command has been issued any number of vertical bar graphs may be drawn unless the characters are redefined by another command 5 1 3 Draw vertical bar graph 254 61 column height Draws a vertical bar graph in column having a height of height pixels The height may range from 0 to 20 0x00 to 0x14 pixels The necessary characters must first be initialized by either of the commands shown in section 5 1 1 or 5 1 2 which will determine the width of the graph drawn Graph may be erased by drawing a bar graph of height 0 in the same column 5 1 4 Initialize horizontal bar graph 254 104 This command defines the 8 special user characters to be blocks suitable for use in drawing horizontal bar graphs Any previously existing definitions will be lost Once this command has been issued any number of horizontal bar graphs may be drawn unless the characters are redefined by another command 5 1 5 Draw horizontal bar graph 254 124 column
31. text display Built in font with provision for up to 8 user defined characters Speeds from 1200 bps to a lighting fast 19 2 Kbps over RS232 Communicate over DC or RS232 with software controlled speed Use up to 16 modules on the same 2 wire PC interface Fully buffered so that no delays in transmission are should be necessary Software controlled contrast Backlight with configurable time out setting up to 180 minutes Use up to a 25 key keypad with a 10 key buffer Six general purpose outputs for a variety of applications Horizontal or Vertical bar graphs Variable power options 5V or 7V to 15V or 7V to 30V Extended temperature option Fits our PC Bay inserts without any modifications 1 1 What it Does The LK204 25 is designed as the display unit for an associated controller The controller may be anything from a single board special purpose microcontroller to a PC depending on the application This controller is responsible for what you see on the screen of the LK204 25 The LK204 25 provides a simple command structure to allow text and bar graphs to be displayed on the screen Text fonts are built in and use standard ASCII mapping Provision is made for up to 8 user defined characters 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 General purpose out
32. than one category Before issuing commands to the LK204 25 please read sections 7 2 and 7 3 6 1 Command List 6 1 1 Clear display 254 88 This command clears the display and resets the text insertion point to the top left of the screen 6 1 2 Set contrast 254 80 contrast This command sets the display s contrast to contrast where contrast is a value between 0x00 and 0xFF between 0 and 255 Lower values cause on elements in the display area to appear lighter while higher values cause on elements to appear darker Lighting conditions will affect the actual value used for optimal viewing Individual LK204 25 modules will also differ slightly from each other in appearance In addition values for optimal viewing while the LK204 25 backlight is on may differ from values used when backlight is off 6 1 3 Backlight on 254 66 minutes This command turns on the backlight for a time of minutes minutes If minutes 1s zero 0 the backlight will remain on indefinitely Note the factory default for backlight is on 6 1 4 Backlight off 254 70 This command turns the backlight of the LK204 25 off 6 1 5 General purpose output off 254 86 gpo This command turns OFF any of the General Purpose Outputs see section 2 2 for a description of the GPOs gpo is 1 to 6 Note that OFF means that the output floats 6 1 6 General purpose output on 254 87 gpo This command turns ON any of the General Purpose Outputs
33. the PC plug in your keypad If your connector has fewer pins than the one on the LK204 25 center it as well as possible Note 1 The keypad connector must be wired with columns on one side and rows on the other side of the center of the connector If your keypad isn t wired this way you will need to make an adapter or rewire the connector to meet this requirement Note 2 The connector is reversible Reversing the connector will not damage the keypad or the LK204 25 but it will change the ASCII character map 3 Press a key on the keypad An upper case ASCII character A Y should appear on the PC screen Different keys should generate different characters If you want to experiment reverse the connector and see if it generates a more logical set of characters Ultimately the program in your controller will have to map these characters to the ones marked on the keypad which will likely be different LK204 25 rev 1 6 2 Connections 2 1 Connector Pinout Refer to the diagram below for this chapter r RS 232 Sp d gt gt m nd I2C Seftings Ze a ee nny HHE a ened G t Ee a a a Connector Figure 2 1 Electrical Connections The LK204 25 has four connectors Connector Function 14 pin dual header General purpose outputs 6 see section 2 2 4 pin power 5 0 VDC and TC communications see section 2 1 1 10 pin header Keypad see section 3 4 12 DB 9F RS 232 pow
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