|
SERIAL LCD
DISPLAY
SELD
With this project you can send serially data to an LCD display
(with Hitachi HD4478 or compatible controller).
In this way you can save a lot of Program Memory Space and
Micro In/Out ports.
You need only 1 PIC 16F84 (or any other cheaper Pic Microcotroller)
and few connections.
You can connect SELD to another PIC/Micro or terminal with
only 1 wire.
It is possible to send data to the display also from the PC
via standard serial port (you can use any Terminal program
or my Pic Terminal).
Seld can receive data at 2400bps and send it at 9600 bps to
the LCD display.
CIRCUIT
It is the same circuit found in PBP manual except for Debug
Output Pin (PortB.0) and Serial Input (PortB.1) .
You don't need to connect debug pin :it is only for testing.
The debug instruction may cause some error if you send data
to seld very fast.
For this reason there are 2 different files.
The first (Serlcd.bas) is for testing with a terminal program
or a pic (you should use a delay between each characters)
The second one is for normal operation (pic,termianl,micro....).
Data is sent from the remote controller (another Pic,Micro,PC,....)
to PortB.1 of the Pic 16F84 .
SELD send each character received from the serial input (at
2400 bps) to the LCD display.
You can send also special commands like Clear Display or Cursor
Movement.
I have decided to follow the same commands syntax reported
by Hitachi Datasheet and PBP manual.
You can modify the syntax in any way.
FAST TEST
Connect your pic to an LCD display as indicated
above.
Connect the pic to your computer as indicated in PBP manual
(debug and serin).
Open a Terminal Program (as PIC TERMINAL) . Select 2400 bps
or 9600 bps (depending by the file you have downloaded) and
the right Com port.
Com port open.
SELD is ready to receive data.
Type standard characters or commands.
I have written "LCD test".
After I have cleared the display sending :
$fe,1
To go to the second line just send $fe,$c0
Now I'm sending a text file with words and commands from
PC to Display:it is very easy to display any kind of
data .
FAST TEST
WITH ANOTHER PIC
Download Seltst.bas (or .hex) and program another 16F84 4
Mhz Pic.
Connect portb.0 of this new pic to Seld's portb.1 .
Give power and look at the display.
The program makes many tests. It sends individual characters
(every type) ,sends commands and sentences.
Download Seld Code in PBP format (txt
format):this is the reale operative program
Download Seld HEX for Pic16F84 4Mhz
Download Serlcd Code in PBP format (txt
file):this is the test program (it works also at 9600bps)
Download Serlcd HEX format for PIC16F84
4Mhz
Download a demo txt file
Download the Seltst Code in PBP format
(txt file):this is the test program you have to load in another
Pic for testing Seld
Download Seltst HEX format for PIC16F84
4Mhz (2400bps)
Download this page in PDF format and all
the other files
If you know how I can improve my project,just contact me
|
