thermal mini printer

please check the previous link the schematic is opening please check and tel us if its correct pls pls

please attach your figure or schematic properly or else your post will be deleted

---------- Post added at 13:19 ---------- Previous post was at 13:17 ----------

pls check the schematic and tel us if its correct so that i can go for soldering and programming ..........pls help us soon its very urgent

why are you connecting pin 4 (DTR).. pin3 of db9 should be connected to pin13 of max but it is not at all connected.... check max 232 circuit properly...

The RS232 interface at the PIC side is mysterious. I would expect dedicated RX and TX pins (hardware UART) connected to the MAX232.

You also managed to confuse simple things as a transistor relay driver. Unless you have unsaid special intentions, you should go for the text books standard common emitter configuration with current limiting base resistor and a free-wheeling diode for the inductive load.

pls check with this schematic i have corrected a bit.

Looks better now. Did you check, that the thermal printer can be operated with 1 or maximum 1.5 A from 7805 voltage regulator. Some devices have a rather high peak current.

hi....i m sending u the details of the thermal printer i m using.This printer can be operated with 2amps can u pls tel me if i hav to do any corrections in my schematic for 2amps.....or this schematic is fine to continue with my project....this printer has a charger connected to it.......pls reply soon.......

this printer has a charger connected to it

Click to expand...

???
If the printer is intended be powered by the 5V supply shown in your schematic, a voltage regulator with higher current rating should be used. Also the 1000 uF capacitor should be enlarged to e.g. 4700 uF and a transformer with sufficient current delivery connected.

The printer current consumption depends a lot on the firmware - there are many tricks which can reduce the current from 2A to 200mA (on the price on slower printing speed).

Use seperate charger for printer and seperate charger for you kit...
5V regulator cannot withstand 2Amps current....

hi.....
the thermal printer i m using is a ready made printer with a charger so i dont hav to bother about the power supply for it...i just hav to connect it to relay for data....can u pls tel me if i hav to connect pin no 1 and 2 to ground and pin no 3 and 4 to vcc of power supply of my circuit....or i just have to connect RX and TX of printer to NC1 and NC2 of relay....pls help me soon i m really confused.....

so i dont hav to bother about the power supply for it

Click to expand...

If so, it can't be identified in your schematic

can u pls tel me if i hav to connect pin no 1 and 2 to ground and pin no 3 and 4 to vcc of power supply of my circuit

Click to expand...

We can't know. Check the documentation shipped with the printer. Or ask the supplier.

ok thanks a lot for helping me...........

hi.........
can anyone pls help me in programming for my project.......can u pls tel me how to go about it ....wher to start from............pls help me soon.

hi..........can anyone tell me how to use hyperterminal for pic............

hyperterminal is in start -> programs-> accessories-> communication-> hyperterminal

when you open it will ask for country code you cancel that.

in one window it will ask connect using .......... there select the COM port

then it will open port setting select the correct baud rate, 8 data bits 1 stop bit and no parity and flow control none.... t
thats all... connect it to PIC and use it

hi .........i hav changed my schematic i m using three switches wen ever i press sw1 the labels should be printed n so on ................i hav to send this data to hyper terminal can u tel me wat to do ...........its working in simulator mode ......should i make some changes in the program pls help me out soon...........

this is my code

#include<htc.h>
#define MYSW1 PORTBbits.RB5
#define MYSW2 PORTBbits.RB6
#define MYSW3 PORTBbits.RB7
void SerTx(unsigned char);
void main()
{
unsigned char z;
unsigned char mess1[]="label";
unsigned char mess2[]="Barcode";
unsigned char mess3[]="Tocken";
TRISD=0X00;
PORTD=0X00;
TRISBbits.TRISB5=1;
TRISBbits.TRISB6=1;
TRISBbits.TRISB7=1;
TXSTA=0x20;
SPBRG=15;
TXSTAbits.TXEN=1;
RCSTAbits.SPEN=1;
if(MYSW1==0)
{
for(z=0;z<5;z++)
{
while(PIR1bits.TXIF==0);
PORTD=mess1[z];


}
PORTD=0X00;
while(1)
{
SerTx('n');
SerTx('a');
SerTx('m');
SerTx('e');
PORTD=0x00;
SerTx('c');
SerTx('l');
SerTx('a');
SerTx('s');
SerTx('s');
PORTD=0x00;
SerTx('c');
SerTx('o');
SerTx('l');
SerTx('l');
SerTx('e');
SerTx('g');
SerTx('e');
PORTD=0x00;

}
}

else if(MYSW2==0)
{
TXSTA=TXSTA|0x4;
for(z=0;z<7;z++)
{
while(PIR1bits.TXIF==0);
PORTD=mess2[z];
}
while(1)
{
SerTx('c');
SerTx('o');
SerTx('d');
SerTx('e');
SerTx('3');
SerTx('2');
SerTx('3');
}
}
else
{
TXSTA=TXSTA|0x4;
for(z=0;z<6;z++)
{
while(PIR1bits.TXIF==0);
PORTD=mess3[z];
}
while(1)
{
SerTx('R');
SerTx('s');
SerTx('3');
SerTx('0');
}
}
while(1);
}
void SerTx(unsigned char c)
{
while(PIR1bits.TXIF==0);
PORTD=c;

}

---------- Post added at 15:10 ---------- Previous post was at 13:51 ----------

hi........i dont have usart.h header file for pic16f877a in our system can anyone tel us how to get that header file

use #include "USART.h"
If you see sample code in the installed folder then you can take that file and put it in your project directory....

or download from **broken link removed**

hi....... the above code is working in simulator mode dut its not displaying on hyperterminal..........can u pls tel me soon what s wrong..........pls help soon