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LPH7653-1: 97 x 35 dots graphic LCD interface |
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This is a small I²C 97x35 dots LCD with integrated controller and LED backlight. You'll need these routines to display text or graphics with an 18f452. X and y axe-control: 97 columns (x= 0..96) and 35 rows (4 lines y= 0..4 and three rows). Each character we'll use will have 6x8 dots. All parts are available in our online shop Schematic (Eagle 4.11e), source code (CCS) and hex file available. |
Circuit explanation:
These routines take only 6% ROM and 3% RAM from a 18f452. So there will be enough space left to do other things !!
All important pins are left free for later use: INT0, A/D converters and Timers.
Power save: there is a power save mode available on the module, but sadly enough this mode still takes around 3mA at 5V.
The big advantage is that the module is entirely driven by i²c. The backlight is also nice. Annoying thing about this LCD is that it needs an external -8V, but of course, there's a solution for that! Indeed, i chose to use a simple voltage inverter with a CMOS 555. It could be done more easily with an additional 9V battery, but a portable device with only one battery is more attractive, isn't it?
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Schematic: right-click & "save picture as" for full resolution or (recommended) download the eagle-file below. |
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Available c routines: (ccs compiler)
| routine | ccs c example | explanation |
| lcd_cls(); | lcd_cls(); | clear screen |
| lcd_power_up(); | lcd_power_up(); | power up and initialization |
| lcd_power_down(); | lcd_power_down(); | shut down the module |
| lcd_text(byte cvar); | printf(lcd_text,"LPH7653 module"); | displays the text "LPH7653 module" |
| lcd_gotoxy(byte xlcd, byte ylcd); | lcd_gotoxy(24, 2); | goto column 24 , line 2 // (col 0 to 96) and (line 0 to 4) (line 0 is top) |
| lcd_clear_x(byte ylcd); | lcd_clear_x(60); | clear character beginning on column 60 // (col 0 to 96) (col 0 is left) |
| lcd_clear_y(byte ylcd); | lcd_clear_y(0); | clear line 0 // (line 0 to 4) |
| lcd_clear_xy(byte xlcd, byte ylcd); | lcd_clear_xy(78, 2); | clear character at column 78 , line 2 // (col 0 to 96) and (line 0 to 4) |
| lcd_plot(byte xlcd,byte plot_value8); | lcd_plot(38,31); | place dot at column 38, row 31 // (col 0 to 96) and (row 0 to 31) (row 0 is top) |
| " | x_plot=12; plot_value=15; lcd_plot(x_plot,plot_value); |
place dot at column 12, row 15
// (col 0 to 96) and (row 0 to 31)
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| invert_lcd_video=FALSE; | invert_lcd_video=FALSE; | normal video mode |
| invert_lcd_video=TRUE; | invert_lcd_video=TRUE; | reversed video mode |
| backlight=1; | backlight=1; | turn on the LED backlight |
| backlight=0; | backlight=0; | turn off the LED backlight |
Downloads:
WARNING: may not be duplicated for any commercial use whatsoever without explicit consent from the author (c) Michel Bavin
| Hex file: 015_v5_hex.zip, September 25, 2004: 015_05.hex (to program the PIC) |
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Source code: 015_v5_c.zip (CCS compiler), September 25, 2004 : 015_05.c (with include file lph7653_v2.c ) |
| Schematic: 015_sch.zip (Eagle 4.11e), September 25, 2004: 015_01.sch |
Info & datasheet:
| Graphic LCD module type LPH7653-1: pinout & info and its integrated controller PCF8558 |
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| Voltage inverter with a CMOS 555. | |
Tools:
This project is made with the PCWH CCS compiler ($425,-) You can install Microchip's free MPLAB IDE with it to get things going smoothly.
Programming of the PIC was done with the excellent Tiny PIC bootloader, through the RC6 & RC7 pins. But you'll need a regular PIC programmer to write the PIC the first time with though...
Eagle 4.11 was used for the schematic & PCB layout.
