Sir plz tell me
how to give the input message

Sir I want to use 2 transmitters at different locations . Transmitter-1 using b0, b1 input pins & Transmitter-2 using b2, b3 input pins & 1 receiver using these two transmitter. will it work or how these can be used.
Thanks & Regards

hi everybody, i really want to know how to find out presence of this kind of reciever circuit in which is situated in any cabinet.,please

what is out voltage and current

Sir I have a receiver bought from the market I want to get the signal received history in my computer how can I get this .

our group is doing project on home automation, hence we are using different sensors like IR, PIR, MQ6, etc for security purpose.we have to send the output of these sensors to a single place inside home and we thought of using 3 rf transmitters and sensor and 1 rf reciever to recieve all signal. the problem is reciever receives data from only one transmitter and not from other two.plz help me out sir.our project is struct in midway. waiting for reply

hello sir.. can i know the transmission rate of the module? how many bits can it transmit in 1 second.. i am trying to transmit an image using this.. is it possible?

can i use transmitter & receiver in voice recognizing quadcopter

Catching unwanted signal or noise ?

how to make a remote control car ? With transmeter and reseaver can you give me a diagram. Pleeeeeeese

I COULDNOT FIND THE 1.1 M AND 51 K RESISTOR SO AM USING 100K 1 M 39K AND 12 K ATTACHED TO GET THE DESIRED VALUES BUT LET ME MAKE SURE SOMETHING IS THE WATTAGE OF RESISTORS 1/4 W?

Sorry, please elaborate your project. You can use above circuit to transmit small data.

Sir,
I want to connect calculator to transmitter how to connect it?Can I use any transmitter with any reciver?

It is 100m as per the specification of the module.

how long or distance it can pass data?

Yes, you can try….

You may use some digital circuit to send 8 bits vai 4 channels.

i wana make the transmitter and receiver any body help mee???

hello, I just want to transfer Logic 0 or 1 to control a Buzzer/ Relay with this circuit with out adding the encoder /decoder. Is it possible??

Sorry, I am not sure about it.

I don’t think. How it will work if antenna is shorted to ground ?

I haven’t yet used the 4 pin one. It will be another design that’s all.. Even in 8 pin. only 4 pins are used. VCC, GND, DATA and ANT.

I have a 434 MHz RF Receiver (8-pin) module. I am finding the ANT pin is shorted to its adjacent GND pin. Is it normal?

sir,
I have 12 different data lines from micro controller, I need to transmit this wireless, Please suggest a method.

I don’t think you can do it using these modules.

sir,
is there any way that i can compare the signal strength at the receiver side with a reference point.
thank you sir.

Yes, it is possible.

Delay time ?? I think it is fast enough. You can even transmit low baud rate UART wirelessly.

Sir, can i use rf modelule and interface with at89c51 without using decoder and encoder?

hallo sir
i want to make rf 4 wheel car for roborace
wireless
so plz suggest me what components will need?how to make pcb connection plz provide circuit diagram plz i need ur help my id is [email protected]

If I have two identical rf receivers placed at different distances from the rf transmitter.(let’s assume they’re differing by quite a distance. They’re not very close.) Will the nearest receiver receive a signal with higher strength or will both receive the same strength? If yes, can I compare the signal strengths, a logical comparison to find out which is stronger using the values received by the receivers.Thanks.!

What ?

Receiver will work only with 5V supply. Don’t provide 12V.

Yes, you can use like that … no problems.

If you want to operate it only during the running time of dynamo, you can connect it after filtering and regulating.

if my receiver is at 12 volts than what voltage should i apply to the transmitter ckt???
plz help me out.

This circuit is 100% working. Thanks! Thanks!
Sir, can you tell what is the current at the output?
I want to run a 5v motor or speaker at output.

hello sir;
i wanted to connect 4 dc, 12V motors(wireless);for d tyres so dat d car can turn left nd right,foward nd backward;
and 1 on-off switch(wireless) for another 12V motor;
how can i use the data lines.????

If you want to use 2 pairs at a time, you should use different frequencies 315Mhz and 434Mhz.

Hi sir,
Thank you for this information,
Please help me on this,

how can I use 2 transmitter and 2 receiver with ht12e/d,
and how can I enable and disable TE pin according to first transmitter and 2nd transmitter,
and how can we use A0-A7 pin for both transmitter and receiver.

please help me on this,
I am not able to use 2 transmitter and 2 receiver for increasing the range .

sir can i use 433 rf transmitter and receiver with ht12 e and ht12 d? tnx

Thanks for your feedback.

Whats the voltage to get maximum range?

#include

#include

__CONFIG(0X3F32);

#define _XTAL_FREQ 12000000

#define RS RB1 //LCD PINS

#define E RB0

#define DATA PORTD

#define B1 RB2

#define RELAY RB3

#define R1 RC0 //ROW-output

#define R2 RC1

#define R3 RC2

#define R4 RC3

#define C1 RB7 //COL inputs

#define C2 RB6

#define C3 RB5

#define C4 RB4

char *s;

int k,o,t,h,th;

char in[4];

unsigned long int i1=2215486;

unsigned char value[4][4]= { ‘1’,’2′,’3′,’4′,

‘5’,’6′,’7′,’8′,

‘9’,’A’,’B’,’C’,

‘D’,’E’,’F’,’0′ };

char p[4]={‘1′,’2′,’3′,’4’};

void cmd(unsigned char c)

{

DATA=c;

RS=0;

E=1;

__delay_ms(10);

E=0;

}

void data(unsigned char d)

{

DATA=d;

RS=1;

E=1;

__delay_ms(10);

E=0;

}

void printxy(const char *w,int r ,int c)

{

int i=0;

if(r==1)

{

for(i=c;i<*w!='';i++)

{

cmd(0x80+i);

data(*w);

w++;

}

}

if(r==2)

{

for(i=c;i<*w!='';i++)

{

cmd(0xc0+i);

data(*w);

w++;

}

}

}

void digit4xy( unsigned int digit,int r,int c1)

{

int c=c1-1;

o=digit%10;

t=(digit%100)/10;

h=(digit%1000)/100;

th=(digit%10000)/1000;

if(r==1)

{

cmd(0x80+c);

data(th+0x30);

c++;

cmd(0x80+c);

data(h+0x30);

c++;

cmd(0x80+c);

data(t+0x30);

c++;

cmd(0x80+c);

data(o+0x30);

}

if(r==2)

{

cmd(0xc0+c);

data(th+0x30);

c++;

cmd(0xc0+c);

data(h+0x30);

c++;

cmd(0xc0+c);

data(t+0x30);

c++;

cmd(0xc0+c);

data(o+0x30);

}

}

unsigned int getkey(void)

{

int row,co,dummy,flag=0;

R1=R2=R3=R4=0;

//__delay_ms(1000);

R1=1;R2=0;R3=0;R4=0;

{

//__delay_ms(10);

if(C1==1){

while(C1==1);

return '1';

}

if(C2==1){

while(C2==1);

return '2';

}

if(C3==1){

while(C3==1);

return '3';

}

if(C4==1){

while(C4==1);

return 'A';}

}

R1=0;R2=1;R3=0;R4=0;

{

//__delay_ms(10);

if(C1==1){

while(C1==1);

return '4';}

if(C2==1){

while(C2==1);

return '5';

}

if(C3==1){

while(C3==1);

return '6';

}

if(C4==1){

while(C4==1);

return 'B';

}

}

R1=0;R2=0;R3=1;R4=0;

{

//__delay_ms(10);

if(C1==1){

while(C1==1);

return '7';}

if(C2==1){

while(C2==1);

return '8';

}

if(C3==1){

while(C3==1);

return '9';

}

if(C4==1){

while(C4==1);

return 'c';

}

}

R1=0;R2=0;R3=0;R4=1;

{

//__delay_ms(10);

if(C1==1){

while(C1==1);

return '*';

}

if(C2==1){

while(C2==1);

return '0';

}

if(C3==1){

while(C3==1);

return '#';

}

if(C4==1){

while(C4==1);

return 'D';

}

}

return 0xff;

}

int keypressed()

{

int dummy;

do

{

__delay_ms(100);

dummy=getkey();

}while(dummy==0xff);

return dummy;

}

char *getstring(int length)

{

static char f[16];

int i=0;

for(i=0;i<length;i++)

{

f[i]=keypressed();

cmd(0x80+i);

data(f[i]);

}

f[length]='';

return f;

}

void serial_initi()

{

//TXSTA REG

CSRC=0;TX9=0;TXEN=1;SYNC=0;BRGH=1;

TRMT=1;

TXIE=0;

RCIE=1;

//RCSTA REG

SPEN=1;

RX9=0;

SREN=0;

CREN=1;

SPBRG=25;

}

void uart_write(const char d)

{

while(TXIF==0);

TXREG=d;

//__delay_ms(50);

}

void uart_string(const char *w)

{

do

{

uart_write(*w);

w++;

}

while(*w!='');

}

void digit4_uart(unsigned int digit)

{

int a[4];

//int a1=digit;

a[0]=digit%10;

a[1]=(digit%100)/10;

a[2]=(digit%1000)/100;

a[3]=digit/1000;

uart_write(a[3]+0x30);

uart_write(a[2]+0x30);

uart_write(a[1]+0x30);

uart_write(a[0]+0x30);

}

char uart_read()

{

while(RCIF==0);

return RCREG;

}

char uart_ready_send()

{

return TXIF;

}

char uart_ready_read()

{

return RCIF;

}

char uart_read_string()

{

int i=0;

do

{

s[i]=uart_read();

i++;

}while(uart_read()!='');

return *s;

}

void uart_enter()

{

uart_write(0x0d); //

uart_write(0x0a); //

}

void gsm_initi()

{

uart_string(“AT”);

uart_enter();

uart_string(“AT+CMGF=1”);

uart_enter();

__delay_ms(100);

}

void send_message(const char *msg)

{

gsm_initi();

//uart_string(“AT+CMGS=”);

//uart_write(‘”‘);

//uart_string(“9597422089”);

//__delay_ms(300);

uart_write(‘”‘);

uart_write(0x0a);

__delay_ms(300);

uart_string(msg);

__delay_ms(300);

uart_enter();

uart_write(0x1a); //control z

__delay_ms(300);

}

unsigned int random()

{

while(B1==1)

{

i1++;

digit4xy(i1,2,7);

}

__delay_ms(200);

return i1;

}

char *otp_string()

{

int otp=0;

otp=random();

digit4xy(otp,2,6);

char a[4];

a[0]=otp%10;cmd(0xc0);

data(a[0]);

a[1]=(otp%100)/10;cmd(0xc1);

data(a[1]);

a[2]=(otp%1000)/100;cmd(0xc2);

data(a[2]);

a[3]=(otp%10000)/1000;

cmd(0xc3);

data(a[3]);

return a;

}

void lcd_initi()

{

cmd(0x38);

cmd(0x06);

cmd(0x0c);

cmd(0x01);

//cmd(0x0e);

}

void main()

{

TRISD=0X00;

TRISC=0B10110000;

TRISB=0XF0;

lcd_initi();

serial_initi();

int i=0,op=3333;

RELAY=0;

while(1)

{

printxy(“OTP TEST”,1,2);

//uart_write(‘k’);

//digit4_uart(op);

char k;

k=random(); //getting OTP as string

digit4xy(k,2,1);

//gsm_initi();

uart_string(“AT”);

uart_enter();

__delay_ms(50);

uart_string(“AT+CMGF=1”);

uart_enter();

__delay_ms(50);

uart_string(“AT+CMGS=”);

uart_write(‘”‘);

uart_string(“9597422089”);

uart_write(‘”‘);

uart_enter();

__delay_ms(50);

uart_string(“YOUR OTP IS:”);

//uart_enter();

__delay_ms(50);

digit4_uart(k);

uart_write(0x0a);

__delay_ms(50);

uart_write(0x1a); //control z

cmd(0x01);

printxy(“MSG SEND”,1,1);

__delay_ms(500);

printxy(” TYPE PASSWORD”,1,1);

char check[4];

check[3]=k%10;

check[2]=(k%100)/10;

check[1]=(k%1000)/100;

check[0]=k/1000;

__delay_ms(500);

for(i=0;i<4;i++)

{

in[i]=keypressed();

cmd(0xc0+i);

data(in[i]);

}

if(in[0]==th+0x30&&in[1]==h+0x30&&in[2]==t+0x30&&in[3]==o+0x30)

{

cmd(0x01);

printxy("MATCHED",1,1);

RELAY=1;

//continue;

}

else

{cmd(0x01);

printxy("NOT MATCHED",1,1);

RELAY=0;

break;

}

__delay_ms(500);

cmd(0x01);

}

}

Hello sir,
How can i flash hex file in HT12D/E ?
i am using universal programmer IC kit box, but i am not able to flash image,
can u plz help me, which kit box , we have to use ?

The transmission range varies with the applied voltage.

Argentina. Nevermind, i found a pair. It doesn’t matter what voltage I use (3-12)V, i will always use a 1.1M ohm resistance in the ht12e circuit?

I think you can use the modules directly.

i want to operate wireless buzzer on off using rf module

Sir, at receiver, 15-16 pin requires 51k can I use 55k?

Yes, you can use it.

I think you need to invert the output of receiver module before connecting it to uart input.

Yes.. you can use it.. but you should use lowest baud rate.

It is hard to find the pair of HT12 in my country. Is it possible that I could replace them with some other decoder/encoder Integrated circuit?

If otherwise I connect it to 220 V previously adapted to lets say 6 V, should i use a voltage regulator(adaptate to 5 V) to protect the circuit against electrical surge(diodes won’t work)? Or the 6 V adaptator would do the job?

Nop.

Just put a diode in series.. it will drop 0.7V.

Do i have to make any change to the circuit if the receiver circuit is supplied with a 6 Volts or 4.5 VCC(it’s because i can only get batteries of 1.5 Volts, so I plan to put 3 of them together for 4.5 or 4 for 6 volts. I don’t want to craft a voltage divider subcircuit or use a lm317 voltage regulator.

You can use above circuit for that.

I want to make wireless device which can receive the data upto 90 degree upto 20 meter. can any body help?

You may use a 315Mhz and a 434MHz for that. But it is better to send 8 bit data as 2 parts sequentially with 1 pair. You may also use UART with low baud rate.

Make sure that you are using correct oscillator resistors.

Sorry, I haven’t yet used ST12.

what does that mean exactly? does this mean that, if I for instance, apply a Constant 5 Volts to a digital input of the encoder, does this mean the output on the reciever will be a 5V output (i.e. is the digital equivalent of logic 1 – 5V)

Sorry, I haven’t yet used that module.

This is digital transmitter and receiver..

It can transmit more than 100 meters with proper antennas.

mai i know the range of transmitter

Good day,pls i did my own circuit but the transmitter and the receiver are not communicating. how can i troubleshoot the problem pls? and i must get it done today! someone pls help

hi ..
can we use 8pin switch for the address code rather then grounding all?

sir shall we use ordinary radio as a receiver tuned to the particular frequency?

Is this transmitter module compatible with your design?

www (dot) alexan (dot) com (dot) ph/downloads/alexan_rf (dot) pdf

This modules has 8 pins for the transmitter while what you used with your design only has 4 pins. Can youhelp us in implementing this module (attached link) with your design? What should we do with the transmitter module connections?

Are we going to have problems with this module (attached link) ?

Hi,
I have made a similar circuit using 434mhz module. I have used ht12e and ht12d ICs. Between osc1 and osc2 I have used 750k resistor for ht12e and a 33k resistor for ht12d. I have kept pin 3 of receiver (linear o/p) open. And I have not yet connected antenna in either Tx or Rx. Everything else is the same as in your blog. But my circuit is not at all working even if i keep Tx and Rx 5cm apart! Please guide me to solve my problem! Thanks!

Can this module be used with the ciruits in this page? The Transmitter have 8 pins instead of four.

sir i want to need some guidance to controll my pic16f through internet.sir help me please

all data out pins are always high even if i try to have all the data in pins graounded. can i have your email address sir?

i imitated your design and i cant have it working :(( i placed an led on D0 and it’s just always high. the led on the collector doesnt even light up it just sometimes blink 🙁 please help me

Try using ADC… and DAC.. before that find the bandwidth of your transmitter and receiver by using a CRO and Function Generator.

Yes, it is 100% working

Actually, I don’t know.. They might be simpler and low cost..
These are readymade RF module available in the market..

how strong are these ic’s are they the same