4x20 Serial LCD Module (BPP
Contents
1. 5 ASCII 53 then 123 and Enter The 123 will be printed right aligned within the 5 character space Right alignment works only with the standard LCD character set not with big characters cntl B Escape Sequences control ASCII 27 followed by additional parameters BPP 420 understands two instructions that begin with the escape code ASCII 27 e Define a Custom Character ESC D n BO B1 B2 B3 B4 B5 B6 B7 The BPP 420 has eight custom character slots These characters are Serge Byte Values mapped to ASCII codes 128 through 135 At startup the unit loads She ee Bian deena bitmaps into these slots for the big character cntl B mode Using byte 0 1xx00000 128 1xx00100 132 the Define instruction you can change a bitmap Send Escape ASCII gt y e iz 27 followed by the letter D ASCII 68 then the symbol number you v e wish to define 0 7 ASCII 48 55 followed by eight bytes defining LHI the bitmap The contents of those bytes map to the custom character m B suas as shown in figure 4 byte 6 iodo 125 NOTE If you redefine any of the custom characters you must restore ye E A them using ESC E before using big character mode 1xx00010 130 Hl 1xx11111 159 1xx00010 130 x is don t care bit Figure 4 Defining a custom symbol see www seetron com for bitmap design tools e Restore Default Custom Cha2. to 50 C 32 to 122 F Serial data rates 00 eeeeseeeeeeeseeeeeeeeeeteaeeeaeetsaeeseeeeaaes 2400 or 9600 bps i 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA Sc ott Edw a rds El ectronic S l nc ph 520 459 4802 fax 520 459 0623 www seetron com
3. 2nd line from a terminal program press control P and type 21 followed by a space or other character which will be discarded One byte method Send the display position as a single byte value equal to the position plus 64 F or example to move to position 21 you would send control P ASCII 16 followed by ASCII 85 21 64 Clear Column control Q ASCII 17 Clear the current column and advance the cursor to the next column same line This feature can be used to clear a four line high section of the screen Figure 3 Layout of the 4x20 LCD i 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA Sc ott Edwards El ec tronics l nc ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 6 Right align Text control R ASCII 18 Accept a number from 2 to 9 as text representing the width of an area on the screen in which right aligned text is to be printed Cursor will back up that number of characters from present cursor position Subsequent text will be stored without printing to the screen until one of the following is received e The specified number of characters e A control character ASCII 1 31 e A decimal point the period character ASCII 46 The display will print the text with right alignment and erase any leftover text within the specified width For example move the cursor to the right end of the screen send control R ASCII 18 followed by
4. Dimensions based on information provided by manufacturers subject to change without notice Figure 6 Physical dimensions VAN Important Notes on Handling Installation and Mounting LCDs are precision made electro optical devices that should last a lifetime of normal use They are vulnerable to damage from mishandling however Our warranty excludes damage from abuse so it is very important that you handle and mount your LCD with care Here are some tips e Handle in a static safe manner e Do not use glue epoxy or paint on this unit e Do not drop or strike e Protect from water solvents oils Do not attempt to disassemble repair or modify e Do not bend warp or stress e Do not drill cut notch grind etc e Install behind a protective transparent window e Mount with machine screws in corner holes e Protect from strong electrical fields ESD Do not attempt to enlarge mounting holes e Protect from reverse power hookup Table 2 Basic Power requirements BL Off eeeeeeeeeeeeees 4 8 to 5 5 Vdc 10mA Specifications Power requirements BL ON cccccceeseseees 4 8 to 5 5 Vdc 100mA User connector eee 5 pin header 0 025 posts on 0 10 centers Connector PINOUt eee eeeeeeeeeeeeeeeeeeeeeeeeteeeeeaees 5 GND SER GND 5 Serial input RS 232 or inverted TTL CMOS 9600 or 2400 N81 Buzzer output 5V 25mA max pulses approx 100ms for BELL Operating temperature 0
5. in big numbers in the middle of the screen Pause a half second between numbers for b2 0 to 99 serout 0 n2400 posCmd 70 bigNums b2 pause 500 next b2 END Finished Sc ott Edw ards El ectroni Cs nc 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 8 Program Examples cont Program 420DEMO BS2 Demonstrate 4x20 Serial LCD with Stamp II This program demonstrates many of the features of the 4x20 Serial LCD Module from Scott Edwards Electronics Set the module to 9600 bps S1 switch 1 down 2 up Connect the serial input of the module to BS2 pin P0 GND to GND and 5V to 5V Run this program l Define names for LCD instructions bps noCurs con 4 Make cursor invisible ulCurs con 5 Show underline cursor clrLCD con 12 Clear entire LCD screen posCmd con 16 Position cursor clrCol con 17 Clear column wedge con 128 Wedge shaped symbol bigNums con 2 Begin big numbers N9600 con 4054 Baudmode for inverted 9600 bps output The constants bell and bksp are predefined in PBASIC2 Begin demonstration pause 1000 serout 0 N9600 clrLCD Clear the screen for b2 0 to 79 serout 0 N9600 wedge Fill screen with wedges next pause 1000 Wait 1 second serout 0 N9600 posCmd 68 Move to pos
6. to send cntl E underline cursor hold down Control and press E To send control codes from a program send the ASCII value as a single byte not as a text representation of the number Using cntl E as an example send a single byte containing the value 5 00000101 binary Control codes not listed in the table are ignored by the BPP 420 and have no effect Table 1 Display Control Codes Function Code ASCII Null ignored prior to buffer cntl 0 Cursor home cntl A 1 Start big characters cntl B 2 End big characters cntl C 3 Hide cursor cntl D 4 Show underline cursor cntl E 5 Show blinking block cursor cntl F 6 Bell pulse piezo buzzer output cntl G 7 Backspace cntl H 8 Horizontal tab cursor to next multiple of 4 column cntl I 9 Smart linefeed cursor down one line cntl J 10 Vertical tab cursor up one line cntl K 11 Formfeed clear screen entl L 12 Carriage return cntl M 13 Backlight on cntl N 14 Backlight off cntl O 15 Accept cursor position entry cntl P 16 Format right aligned text cntl R 18 Begin special instruction ESC cntl 27 NOTE New rev 4 0 custom character instructions ESC D and ESC E begin with the Escape character see listings under Escape at the end of this section Null control ASCII 0 Nulls are ignored sending a null to the display has no effect However unlike other unused codes nulls are not even stored in the display buffer They may be used as a brief time delay whose length depends o
7. CII 4 Hide the cursor either type blinking or underline Show Underline Cursor control E ASCII 5 Show a non blinking underline cursor at the printing location Show Blinking Block Cursor control F ASCII 6 Show a blinking block cursor at the printing location Bell control G ASCII 7 Pulse J 4 for approximately 100 ms to beep piezo buzzer Backspace control H or backspace key ASCII 8 Move the cursor back one space and erase the character in that space Horizontal Tab control I or Tab key ASCII 9 Move the cursor forward to next multip eof four column Smart Linefeed control J ASCII 10 Move cursor down one line If immediately preceded by carriage return linefeed is ignored Vertical Tab control K ASCII 11 Move cursor up oneline Clear Screen control L ASCII 12 Clear the screen leaving the cursor in position 0 see figure 3 Carriage Return control M ASCII 13 Move the cursor to the first position of the next line Backlight ON control N ASCII 14 Turn on the LED backlight Backlight OFF control O ASCII 15 Turn off the LED backlight Position Cursor control P ASCII 16 Accept a number 0 to 79 and move the cursor to that position where 0 is the 1st character of the 1st line and 79 is the last character of the 4th line see figure 3 Number may be in text or single byte format Text method Send the desired display position as a printable text F or example to move the cursor to position 21 2nd character
8. User s Manual BPP 420 v4 0 2 03 pg 1 4x20 Serial LCD Module BPP 420 v4 0 The BPP 420 is an LCD module with attached serial interface This combination works like a simple serial receive terminal at 2400 or 9600 baud switch selectable Common control codes like carriage returns linefeeds tabs backspace etc are supported The display also implements instructions for cursor positioning backlight control large character display and right aligned printing New Features in Rev 4 0 This latest version of BPP 420 has the following new features e Ability to redefine custom block graphics characters e J umper pads to increase backlight brightness or set backlight always on e 64 byte buffer large alpha A Z characters right alignment introduced in rev 3 0 The revision is identified by BPP4 PT printed in the lower right portion of the serial daughterboard Table of Contents Pinout ofthe BPP 420 PE E EAT E T T 2 Aola TOTEE IlO EEEIEE ATAT E T 2 Hookup Tor Use E E T 2 Pize Buzzer Bell zira ae ae a a a aaa aa a a a Ea aeaaaee 3 Backlight Option Pad S Ai rer a a a E E a aaka aeia aT 3 Basic Operation tzira a E a a a A a EA A E seeds teat teen T EE a as 3 Control Codes and Special Features ecccecceeeceeeeeeeeeeeeeeceeeeeeeeseeeeeeeeesaeeseeseaeesneeeeeeseeeeeaes 3 Old Mode Operat O a a e a a ea aa aAa aa aae e aAa AERTS 3 Program n ol CPE E E E casaeg ajebessieccasicesatacecameeseres 7 Dimensions a
9. ack Unless you are using this display to replace an older circa 1996 4x20 serial display leave this switch OFF See note on page 3 Baud Set baud switch 2 OF F down for 2400 baud ON up for 9600 baud Other parameters are always no parity 8 data bits 1 stop bit N81 NOTE The BPP 420 reads the switches only at startup Change settings only with the power off Hookup for Use Figures 1 and 2 show how to connect serial O and power to the BPP 420 Make sure that the power polarity is correct Reversing 5 and GND will damage the BPP 420 and possibly your power supply The power source should be regulated to 5 volts 0 25 volts and be capable of supplying 100mA maximum current draw with the LED backlight on J 1 the 5 pin connector has two extra pins for 5 and GND These pins are arranged in a pallindrome layout If you make a matching 5 pin connector the connections will always line up properly regardless of connector orientation Suitable female crimp sockets for making connectors are available from J ameco www jameco com PN 100765 Digi Key carries ready made 5 pin socket and flex cable assemblies in varying lengths www digikey com example part no A9BAG 0506F N D i 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA Sc ott Edw a rds El ectronic S l nc ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 3 PC Serial comm Port BASIC Stamps adi
10. h as the Windows Terminal or Hyperterminal accessory or Procomm for DOS Set it for the appropriate baud rate matching switch 2 In addition to the baud rate the terminal should be set for no parity 8 data bits 1 stop bit flow control none local echo on OLD MODE Operation The codes and features described in this manual are available only when switch 1 mode is OFF When mode is ON the interface emulates the operation of our original LCD Serial Backpack installed to a 4x20 LCD There are some inevitable differences e BPP 420 draws about 5mA versus 2mA for the older unit e BPP 420 does not require a delay after clearing the screen buffer e BPP 420 controls the LED backlight even when in old compatibility mode Send bytes lt 254 gt lt 255 gt for ON and lt 254 gt lt 0 gt for OFF old mode only New users of this product should always leave switch 1 OFF to usethe newer features NOTE Users of older 4x20 serial LCDs connected the backlight to power separately DO NOT do that with this version Connect power only through J 1 i 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA Sc ott Edwards El ec tronics l nc ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 4 Control Codes and Special Feaures Table 1 lists the BPP 420 control codes To send control codes from a terminal program hold down Control and press another key For example
11. in pin 3 of DB9 pin 2 of DB25 Connect GND of module to com port signal GND pin 5 of DB9 pin 7 of DB25 Configure LCD module for 9600 bps S1 switch 1 down 2 up Connect 5V power to LCD module 5V to 5V and GND to GND Run demo DECLARE SUB pause time AS INTEGER CONST clrLCD 12 Clear the LCD screen CONST noCurs 4 Make cursor invisible CONST ulCurs 5 Turn on underline cursor CONST bell 7 Beep piezo buzzer if attached CONST bksp 8 Backspace CONST bigNums 2 Begin big number mode CONST clrCol 17 Clear column CONST wedge 128 Wedge shaped symbol CONST posCmd 16 Position the cursor OPEN coml1 9600 N 8 1 CD0 CS0 DS0 OP0 FOR OUTPUT AS 1 PRINT 1 CHRS clrLCD Clear LCD FOR i 0 TO 79 PRINT 1 CHRS wedge Fill the screen with wedges NEXT PRINT 1 CHRS posCmd CHRS 68 Move cursor to pos 4 64 4 FOR i 1 TO 12 Clear a 12 column section of PRINT 1 CHRS clrCol CHRS bell screen Ring bell w each loop pause 350 NEXT PRINT 1 CHRS posCmd CHRS 90 CHR ulCurs PRINT 1 4x20 LCD Print message on LCD SLEEP 1 Wait a second FOR i 1 TO 8 PRINT 1 CHRS bksp CHRS bell Backspace to erase messag pause 150 Ring bell w each loop NEXT SLEEP 1 Wait a second PRINT 1 CHRS noCurs Make cu
12. ista AZ 85635 USA Sc ott Edwards El ec tronics l nc ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 2 Pinout of the BPP 420 Connections to the BPP 420 are made through a 5 pin header on the serial interface daughterboard as shown in figure 1 below Note that the photo is upside down with respect to the LCD This was done in order to show the labels on the circuit board rightside up The same board is used with 4x40 LCDs where the labels match the LCD orientation back Closeup of J4 piezo buzzer output 5Vdc at 25mA or less contrast control darker Closeup of J1 pins are 0 025 posts on 0 100 centers 5V o A GND gt ae Serial data gt a Duplicate 5V and GND connections see text Closeup of S1 OF COON 2 BAUD 2400 9600 1 MODE NORMAL OLD Figure 1 Connections and controls Do not reverse 5V and GND even momentarily Reversed power will destroy the electronics A Do not exceed 5 5V into 5 Overvoltage will damage the module Connect power only through J1 Connecting power to other points on the module will damage it Read and follow installation guidelines on page 10 Improper handling voids the warranty Configuration Mode Set the mode switch 1 OF F down to use the features and instructions described in this manual Set mode ON up to emulate operation of the LCD Serial Backp
13. ition 4 64 4 68 for b2 1 to 12 Clear a 12 character swath with pause 350 the clear column feature serout 0 N9600 clrCol bell Ring bell if available each loop next Turn on the underline cursor move to pos 26 and show message serout 0 N9600 ulCurs posCmd 90 4x20 LCD pause 1000 Wait 1 second for b2 1 to 8 pause 100 Backspace to erase messag serout 0 N9600 bksp bel1l1 Ring bell if available each loop next pause 1000 Wait 1 second serout 0 N9600 noCurs Y Tern cursor off Print the numbers 0 to 99 in big numbers in the middle of the screen Pause a half second between numbers for b2 0 to 99 serout 0 N9600 posCmd 70 bigNums dec b2 pause 500 next END Finished Sc ott Edw ards El ectroni cs nc 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA d L ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 9 Program Examples cont Program Q420DEMO BAS QBASIC Demo of 4x20 Serial LCD This program demonstrates the 4x20 Serial LCD Module from Scott Edwards Electronics Inc with QBASIC This program requires slight modifications to run under PowerBASIC or First BASIC available from www powerbasic com A modified version is available for download from www seetron com bpk_exl zip To run this program connect the serial input of the LCD module to the com port transmit data p
14. n the baud rate 2400 bps 4 16 ms delay 9600 bps 1 04 ms Cursor Home conirol A ASCII 1 Move the cursor to the first character position of the first line Begin Big character Display control B ASCII 2 Put the display into big character display mode In this mode characters are displayed as four line tall graphics The display can show up to four big characters at a time The big character set indudes numbers 0 9 letters A Z uppercase only and symbols period hyphen colon and space The display remains in big character mode until it receives a character other than the ones listed or a control C Note that null ASCII 0 will not end big character mode because it is discarded before being buffered The numbers and letters are four columns wide followed by one blank column punctuation and spaces are two columns followed by one blank column Tips for using big characters Give the display approximately 10 ms to draw the characters If you have used ESC D to redefine any of the custom characters send ESC E 1 to reset them to defaults before displaying large characters End Big character Display control C ASCII 3 End big character mode without otherwise affecting the display i 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA Sc ott Edwards El ec tronics l nc ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 5 Hide Cursor control D AS
15. nd SpecificationS a aaa E EAE a A aaae aoaaa aR aaia aa 8 Important Notes on Handling Installation and Mounting cccsseseeeeeeeeeseeeeeeeeeeaee 10 Disclaimer of Liability Scott Edwards Electronics Inc is not responsible for any special incidental or consequential damages resulting from any breach of warranty or under any legal theory including lost profits downtime goodwill damage to or replacement of equipment or property and any costs or recovering reprogramming or reproducing of data associated with the use of the hardware or software described herein Warranty Scott Edwards Electronics Inc warrants this product against defects in materials and workmanship for a period of 90 days If you discover a defect we will at our option repair replace or refund the purchase price Return the product with a description of the problem We will return your product or its replacement via standard shipping Expedited shipping is available at the customer s expense e Note Abusing the module or attempting to repair or modify it voids this warranty Trademarks and Copyrights Windows and MS DOS are registered trademarks of Microsoft Corporation BASIC Stamp is a registered trademark of Parallax Inc All trademarked names referenced herein are the property of their respective holders This manual in its entirety is copyright Scott Edwards Electronics Inc 1995 1999 i 1939 S Frontage Road Suite F Sierra V
16. racters ESC E 1 The big character mode cntl B builds 4 line high characters using the custom character bitmaps ASCII 128 135 If you use ESC D to redefine one or more of these characters big characters won t display correctly To restore the bitmaps needed for custom characters use ESC E 1 That is send ASCII 27 ESC ASCII 69 E and ASCII 49 1 32 40 48 56 64 72 80 88 96 104 112 120 128 160 168 176 184 192 200 208 216 224 232 240 248 To find the ASCII code for a given character add the row and column numbers For example capital D is in the column marked 64 in row 4 so its ASCII code is NOTE ASCII 135 160 are blanks 68 Use the reverse procedure to determine the symbol for a given code For example ASCII code 244 produces the symbol Q found at colum 240 row 4 Figure 5 Character code chart i 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA Sc ott Edwards El ec tronics l nc ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 7 Program Examples Any computer programming language that can produce serial output 2400 or 9600 bps N81 can talk to the BPP 420 The examples here are in BASIC chosen because of its popularity and readability You may download these and other program listings from www seetron com Program 420DEMO BAS Demonstrate 4x20 Serial LCD with BASIC Stamp I This program demonstrates many of the features of the 4x20 Se
17. rial LCD Module from Scott Edwards Electronics Inc Set the module to 2400 bps S1 both switches down Connect the serial input of the module to Stamp pin 0 GND to GND and 5V to 5V Run this program Define names for LCD instructions SYMBOL noCurs 4 Make cursor invisible SYMBOL ulCurs 5 Show underline cursor SYMBOL clrLCD 12 Clear entire LCD screen SYMBOL posCmd 16 Position cursor SYMBOL clrCol 17 Clear column SYMBOL bell 7 Ring bell SYMBOL wedge 128 Wedge shaped symbol SYMBOL bksp 8 Backspace SYMBOL bigNums 2 Begin big numbers 1 Begin demonstration pause 1000 Wait a sec serout 0 n2400 clrLCD Clear the screen for b2 0 to 79 serout 0 n2400 wedge Fill screen with wedges next pause 1000 Wait 1 second serout 0 n2400 posCmd 68 Move to position 4 64 4 68 for b2 1 to 12 Clear a 12 character swath with pause 350 the clear column feature serout 0 n2400 clrCol bell Ring bell if available each loop next Turn on the underline cursor move to pos 26 and show message serout 0 n2400 ulCurs posCmd 90 4x20 LCD pause 1000 Wait 1 second for b2 1 to 8 pause 100 Backspace to erase messag serout 0 n2400 bksp bell Ring bell if available each loop next pause 1000 Wait 1 second serout 0 n2400 noCurs Turn cursor off Print the numbers 0 to 99
18. rsor invisible FOR i 0 TO 99 Show s 0 99 as big numbers theNum LTRIMS RTRIMS STRS i Trim spaces from number string PRINT 1 CHRS posCmd CHR 70 CHRS bigNums theNum pause 500 Wait 1 2 second NEXT END SUB pause time AS INTEGER FOR i 1 TO time PRINT 1 CHR 0 NEXT END SUB Scott Edwards El ectronics Inc 1939 S Frontage Road Suite F Sierra Vista AZ 85635 USA ph 520 459 4802 fax 520 459 0623 www seetron com User s Manual BPP 420 v4 0 2 03 pg 10 Dimensions and Specifications Current BPP 420L models use LCDs manufactured by Powertip older models were made by Truly The sole significant difference is in dimension L the y dimension of the screen frame Powertip Truly A y offset pcb edge to hole ctr 2 50 2 50 B y pcb height 60 00 60 00 C y hole spacing 55 00 55 00 D y screen opening 25 20 25 20 E y character size 4 75 4 75 F x character size 2 95 2 95 G x offset pcb edge to hole ctr 2 50 2 50 L H x screen frame 98 00 98 00 x screen opening 76 00 76 00 J x hole spacing 93 00 93 00 K x pcb width 98 00 98 00 L y frame height 42 00 38 40 mounting hole diameter 2 50 2 50 frame depth non backlit 5 00 5 00 frame depth LED backlit 8 50 8 50 All dimensions in mm Worst case tolerance for any dimension is 0 50mm Maximum depth from front of screen frame to tips of interface header posts is 26mm
19. t Stamp Ji n SER GND vs _ GND DB 9 female solder side oi 2 Soo 5V Vdd ____ 5 a Da i 1 O pin 0 SER power supply Figure 2 Connecting to PC serial port BASIC Stamps Piezo Buzzer Bell As figure 1 shows you can connect a piezo buzzer to the BPP 420 The buzzer will beep when the ASCII bell character cntl G is received The buzzer must have an internal oscillator and work on 5V at 25mA or less Suitable units are ameco 76021 Radio Shack 273 065 and Digi Key P9948 Connecting anything other than a suitable buzzer to 4 will void the warranty Backlight Option Pads BRIGHT and BL_ON Pads marked BRIGHT and BL_ON customize the operation of the LED backlight Soldering a wire across the pads marked BRIGHT changes the current limiting resistance in the backlight circuit from 16Q to 8Q increasing the brightness of the light This increases max current draw to about 150mA Soldering a wire across the pads marked BL_ON connects the backlight directly to the module s power input so that whenever the unit is powered up the backlight is on Do not attempt these modifications unless you are skilled at soldering Damage due to poor soldering is not covered by warranty Basic Operation Set the configuration and connect serial input power to the BPP 420 as shown in the previous sections Now you can send text serially to the display On a PC you may use a terminal program suc
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