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jennifer
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| help choosing a simple lcd and RAM |
 Posted: Tue Aug 11, 2009 4:52 am |
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Hi
i relay want to stay at my new job and need a quick solution to a system that i do  have experience with pic's and ccsc.
In my work, i need to control a 5 step motors and put a small screen, and also a relay small external memory of couple of words.
i have chosen the pic16f877 40 pins , and now i need to choose lcd,ram.
please give me advise of a small popular screen- one or two words- black and white(or just one other color),one line, who can be simply fit the pic16f877 and is easy to use\ i can find code for it.
other thing is the smallest external memory even few bytes, that can fit the pic16f877, i prefer a MicroChip one. or if there is other way to save data in a pic after i turn it off will be good.
please,if you have a chip name,and a specific lcd,that would be good.
thanks a lot.
jenn |
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Wayne_
Joined: 10 Oct 2007
Posts: 681
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| Posted: Tue Aug 11, 2009 5:01 am |
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| For the memory just use the EEPROM or even the flash of the pic it'self to store the data, depending on how often the data will change. |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Tue Aug 11, 2009 8:15 am |
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First off, why do you want external memory?
There better be a good reason. for just a few bytes ((x<25))
And how many boards are you making. 1-10 25,50,100,1000?
for a LCD try a standard 2x16 found everywhere.
http://microcontrollershop.com/product_info.php?products_id=1464
if it needs to be viewed outside in sunlight you may need something special, like super twist, ect.. |
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jenn
Guest
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| thanks |
| Posted: Tue Aug 11, 2009 8:53 am |
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thanks!
i was trying to write to eeprom and it didnt worked.
can someone give me a simple code to write eeprom ?
and about the screen-this screen is steel produced ? is it rs232 ?
thanks ! |
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mkuang
Joined: 14 Dec 2007
Posts: 257
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| Posted: Tue Aug 11, 2009 9:00 am |
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Which eeprom? Internal or external? Post a part number if you are using an external one.
Also I wouldn't be comfortable with the PIC you chose, it only has 8K x 14 of flash which does not seem sufficient for doing what you want to do. |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Tue Aug 11, 2009 9:02 am |
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Here is a 16x2 you can buy from digi-key. many others are available.
It is not serial it uses min 6 pins. d4-d7,Rs,E, and then ground Rw
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=NHD-0216K1Z-NSW-BBW-L-ND
| Code: | #define FIRM_MINOR 17
#define FIRM_MAJOR 'K'
#define HARD_MAJOR 0
#define HARD_MINOR 0
#include <16F877a.h>
#device *=16
#fuses hs,nowdt,noprotect,nolvp,put
#use delay(clock=11059200,RESTART_WDT)
#use rs232(baud=19200,xmit=PIN_B3,invert,stream=debug)
#case
//#zero_ram
#rom 0x2100={1,2,3,4}
void main() {
BYTE i, j, address, value;
fprintf(DEBUG,"\r\n\nICD-U40 EEPROM:\r\n");// Display contents of the first 64
for(i=0; i<=3; ++i) { // bytes of the data EEPROM in hex
for(j=0; j<=15; ++j) {
printf( "%2x ", read_eeprom( i*16+j ) );
}
}
printf("\n\r");
address = 0x2102;
value = 0xBB;
write_eeprom( address, value );
fprintf(DEBUG,"\r\n\nUser change 0x2102 to 0xBB \r\n");// Display contents of the first 64
for(i=0; i<=3; ++i) { // bytes of the data EEPROM in hex
for(j=0; j<=15; ++j) {
printf( "%2x ", read_eeprom( i*16+j ) );
}
}
while (1);
}
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| Code: | #include <18F452.H>
#case
#use delay(clock=40000000)
#fuses h4,nowdt,noprotect,nolvp
#use rs232(baud=19200,xmit=PIN_C0,invert,stream=DEBUG,disable_ints)
#zero_ram
void MyWrite_EEPROM(int16 addr, int8 value);
void main(void){
set_tris_c(0xFF);set_tris_a(0);set_tris_b(0);set_tris_d(0);set_tris_e(0);
setup_adc_ports(NO_ANALOGS);
printf("Start\n\r");
printf("loc1=0x%X\n\r",read_eeprom(1));
printf("loc2=0x%X\n\r",read_eeprom(2));
printf("loc3=0x%X\n\r",read_eeprom(3));
printf("loc4=0x%X\n\r",read_eeprom(4));
MyWrite_EEPROM(1,2);
MyWrite_EEPROM(2,3);
MyWrite_EEPROM(3,4);
printf("loc1=0x%X\n\r",read_eeprom(1));
printf("loc2=0x%X\n\r",read_eeprom(2));
printf("loc3=0x%X\n\r",read_eeprom(3));
printf("loc4=0x%X\n\r",read_eeprom(4));
printf("DONE\n\r");
while(1)
{
}
}
//=== MyWrite_EEPROM ==========================================================
void MyWrite_EEPROM(int16 addr, int8 value)
{
int8 current;
// First Read data. Then only write if the information is different
// Takes longer but cuts down on writes that can wear out the eeprom
current = read_eeprom(addr);
if (current != value){
write_eeprom(addr, value);
}
}
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Last edited by treitmey on Tue Aug 11, 2009 9:41 am; edited 1 time in total |
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Wayne_
Joined: 10 Oct 2007
Posts: 681
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| Posted: Tue Aug 11, 2009 9:26 am |
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| mkuang wrote: | Which eeprom? Internal or external? Post a part number if you are using an external one.
Also I wouldn't be comfortable with the PIC you chose, it only has 8K x 14 of flash which does not seem sufficient for doing what you want to do. |
I think you should read his first post again
| Quote: | | and also a really small external memory of couple of words. |
| Quote: | | other thing is the smallest external memory even few bytes, that can fit the pic16f877, i prefer a MicroChip one. or if there is other way to save data in a pic after i turn it off will be good. |
I think he will find that the pic16f877 which offers both 8K x 14 words of flash and 256 x 8 bytes of EEPROM will be just fine for what he wants. Unless his spec is wrong. |
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jenn
Guest
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| Posted: Tue Aug 11, 2009 11:36 am |
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Thanks everybody.
I just need to use internal eeprom and need the 2 words for this command.
and only need a normal screen that uses rs232 (modern!!), and popular.
That's 2 things that will save my system and job !
I really need a name of a rs232 screen as soon as possible.
thanks lot. |
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mkuang
Joined: 14 Dec 2007
Posts: 257
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| Posted: Tue Aug 11, 2009 12:13 pm |
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| Quote: |
I just need to use internal eeprom and need the 2 words for this command.
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The CCS functions to access internal eeprom are write_eeprom(ADDX, value) where ADDX is the EEPROM address and value is an eight bit integer;
and read_eeprom(ADDX). |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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Guest
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| thanks |
| Posted: Wed Aug 12, 2009 12:41 am |
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THANKS A LOT.
It helped me so much.
I just couldn't understand what is the "lcd init" commands.
Does the PIC know a specific lcd? I need to send words in rs232 no ?
Can I find example code for a lcd (parallel and serial) ? |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Wed Aug 12, 2009 7:56 am |
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Where did you see lcd_init()??? in the lcd.c library.
That library was written for the common 2x16 LCD using
d4-d7,Rs,E, and then ground Rw. That library is not for the serial
LCD that you said you wanted. |
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Gabriel
Joined: 03 Aug 2009
Posts: 1067
Location: Panama
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| Posted: Wed Aug 12, 2009 1:01 pm |
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I posted on your other thread...
might help
g
_________________
CCS PCM 5.078 & CCS PCH 5.093 |
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