Uart wirless comuniction module

[ajeesh]

which is the low cost wireless uart module

 

[ckshivaram]

you have Xbee modules, RF modules, BT modules etc.. what you want and what is your specification.....

 

[ajeesh]

i just need low cost one

 

[nandhu015]

rf modules is the cheapest

 

[ajeesh]

my project is transmitting characters from pc via com port to my lpc 2148 board and display characters on lcd . already i have rf module , but continuously characters flowing on lcd without sending from pc when i using rf module

 

[ckshivaram]

its either improper coding or problem in handling VT and TE pins of RF modules.........

 

[ajeesh]

its ok on wired connection i mean without rf module

---------- Post added at 18:27 ---------- Previous post was at 18:25 ----------

i think that is noise ....?????

 

[ajeesh]

how can i avoid noise ?

 

[ckshivaram]

what kind of modulation are you using??? and what frequency???? what distance??? and is it a commercial project or a student project???????????

if it commercial project then how critical is it????????, and what LNA do you use?????

 

[ajeesh]

rf modulation , 434mhz, 2 mtr, student project

 

[ckshivaram]

then why you worry of noise... you will never even notice the noise level for your specification..... range is more than 2 mts.....

 

[ajeesh]

but characters are flowing on lcd without connecting transmitter module when i connect my receiver module

 

[ckshivaram]

it is not noise... you are not controlling VT and TE pins.....

---------- Post added at 11:14 ---------- Previous post was at 11:13 ----------

which modules are you using put your code and circuit diagram....

 

[pigbaobao]

Hi friend,

what is the VT and TE pins?? for the LCD or for the PIC?

 

[ckshivaram]

they are pins on transmitter and receiver modules....

 

[anandpv2009]

I believe low cost rf modules are not capable of handling UART data directly. Try any coding techniques like manchester or encoder and decoder ICs HT12E and 12D etc.

Good Luck.

 

[ajeesh]

RF Modules (Tx + Rx Pair) 433 Mhz ASK [RKI-1064] - Rs.425 : Robokits India, Easy to Use, Versatile Robotics Kits... i am using this module

 

[ctownsend]

when having trouble you should ALWAYS,ALWAYS,ALWAYS post a schematic of your circuit so others don't have to GUESS on how to help you.
It sounds like you are not using any encoding in your code. You can use a holtek HT12E encoder for the transmitter and a holtek HT12D decoder for the receiver.

Search and you will find lots of examples.

 

[ckshivaram]

i think circuit is not built... he just have idea... i doubt why he is worrying about noise and module specification for just a simple project... follow the data sheet given for the module.............

 

[engshahrul]

I believe low cost rf modules are not capable of handling UART data directly. Try any coding techniques like manchester or encoder and decoder ICs HT12E and 12D etc.

Good Luck.

Low cost RF Module still can handle low baudrate UART. I have try with 1200bps.