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shashankiim
06-26-2009, 12:50 PM
hi

i new to rf modules...

i recently bought the following rf tx & rx pair...

RF Modules Tx & Rx 315 Mhz ASK

i realized that these devices are easy to use... like sending a high to transmitter data pin will give a high to the data pin at receiver end...

now the problem is that i wanted to run a servo motor using the rf modules however i am facing problems

the circuit is as described...

Tx module : ANT - to a 6 inch Cu wire
Data - Atmega 168

Rx module : ANT - to a 6 inch Cu wire
Data - directly to the data pin of the servo motor...

now when i send pwm to the Tx module there is no sign of servo moving or the Rx module receiving it...

i do not understand why is this not happening ???

also i tried googling abt the "ASK" thing in this regard but couldn't understand much...

an explanation in simple words in this regard would be very helpful..

any help is highly appreciated...

thanks
shashank

suhasm
06-26-2009, 04:43 PM
Why dont you use another uC on the reciever end to control the servo? That will make it easier....

shashankiim
06-26-2009, 06:50 PM
hi

thanks suhasm

thats a nice option but i want to know why is this not working

i wanted to know what is technically wrong in this setup ???

thanks
shashank

pratikmahale
06-26-2009, 11:46 PM
Hi,

Go through this link
http://www.roboticsindia.com//modules.php?name=Forums&file=viewtopic&t=3815&highlight=

Suraj_Swami
06-27-2009, 11:17 AM
Thanks

docel
06-28-2009, 04:02 AM
RF Modules Tx & Rx 315 Mhz ASK

i realized that these devices are easy to use... like sending a high to transmitter data pin will give a high to the data pin at receiver end...



1. They are easy to use alright, but you need some kind of protocol ( order) for your data.
2. You may not have followed the 1-2ms. pulse range. You may not have the pulse repetition @ 50-60Hz.
3. The pwm input to the Tx may not be a true logic transition.
4. some Txs dont work with a 6" antenna. A 1/4th wave vertical antenna is atleast 9" electrical length.