RF Rx Tx Help !!!

[avinash_g]

:lol: Hi Friends,

I have some idea about RF modules but I am confused about different makes available are they all equivalent?What should I see before buying?I need a module that is simple to use and have a good range.

:roll: If you have used any of those please suggest me which one should I buy.

Thanks,
Avinash Gupta

[a7400]

hey avinash

generally these modules are available in two frequencies 315MHz and 433Mhz
they are usually modulated with ASK.
Regarding the MAKE, all the makes are more or less similar since they are all from china/taiwan..

but in the modules itself you might find variations in their looks... you might find one with a visible coil on... these gave slightly better performance when i used them

with respect to how to use them theres an article @ http://www.triindia.co.in/resources/?p=50

[allbits]

beware of their noise!!! they misbehave very regularly.

you might have to keep on transmitting at lower fewuencies to keep them efficient.

[firoz]

can u guys give me some rough idea of cost?

[avinash_g]

The Tx costs Rs 125/- and Rx costs Rs 175/- so the total is only 8O Rs 300+shippings.Check out :arrow: http://www.aplusindia.net/ It is a great place to buy these modules.

:D Enjoy!

[avinash_g]

:D Hello friends,
pls tell me how this modules are interfaced to MCUs.Can i directly connect MCU's USART to these modules for RF serial communication.Pls help.

[Ulhas]

chk aplusindia site

[subhash]

hey ,
avinash, if want rf communication b/n com.and MCU's USART it is impossible
becz generate noise in rf communication , so u should make error correction protocols .

[Ulhas]

aplusindia have diff. module for transmiting serial data chk it out (cost may be around 800)

[reindeer]

You can find Serial and data qualified RF modules at chennai. RS232 to RF converter also available in chennai. I can help you out for your Rf control design :)

[docel]

Reindeer!
I saw the Specifications. Other imported Tranceivers are available locally now for around 650 to 900INR.
Besides, RS232 is a defunct protocol and the new PCs don't support it. What does one do , if there are no COM Ports on the PC?
Can you post the details with cost?
Please post in the Buy & Sell forum.

[reindeer]

Dear Docel,
OUR RF modules comes with Antenna and Gold plated SMA connector and can support lots of modes of operations and programmable frequency.
Pricing is 900 rupees for a single module with the antenna including shipping charges to anywhere in india. As for the RS232 to RF converter, lots of USB to SERIAL converters are available in local market and one can use them with HYPERTERMINAL in windows to send and recieve data. Its a breeze to do that. Custom Completely made relay controls are also available. You can mail me for all the detials at project@reindeersystems.com
regards
vinod

[maxisms]

hey i used the widely available TX RX ASK modules with encoder/decoder ics for my wireless robot.I had used in to drive 4 motors, but experienced a latching problem. the signal was getting latched even when there was no input given to the encoder. Why is this happening? It is more prominient when using 9v cells and less prominient when using a fixed dc supply.the current drawn was about .5 amps
any idea why latching takes place and how do i eliminate it

[tpsbpl]

I had used in to drive 4 motors, but experienced a latching problem. the signal was getting latched even when there was no input given to the encoder. Why is this happening?
any idea why latching takes place and how do i eliminate it
i also faced same prob using DTMF signals for Rx Tx :(

[docel]

1. Place 0.47uFd ceramic caps across the Motor terminals.
2. Don't use a 9v battery for ANYTHING that has a motor (Four????) !

tpsbpl

i also faced same prob using DTMF signals for Rx Tx

So??
How does that help Maxisms ?? :evil:

[BUY2IN1]

FSK Rx/Tx Module

Calling all RF enthusiasts, hobbyists

What would you pay to make a FSK RF based remote control of 434MHZ – 400m range??????
RF module –
FSK Receiver Module – Rs 350/- onwards
FSK Transmitter Module – Rs 350/- onwards
Then
HT12E IC and HT12D ICs – Rs 35/- each
PCB charges and fabrication – Rs 100/-
Postage Charges Rs 75/-
So you have to pay anywhere between Rs 910/- and above for just the Receiver – Decoder and Transmitter – Encoder Module.

We have product in which Transmitter – Encoder comes in one single module and Receiver – Decoder module in another. READY TO USE…
Dimensions of the module are 3cmx2cm …hence really compact. Minimum external components required. READY TO USE…

Suitable for all kinds of wireless gadgets, remote control, robotics, toys etc.

At a astonishing price of Rs 395 per pair and Rs 95 towards postage and handling
= Rs 490 only per pair (i.e Transmitter, Receiver, Encoder, Decoder)

Email at buy2in1@aol.in for datasheets. Special price for bulk buyers.

visit : www.srivimleshwar.com

[HemantDJ]

Hiii friends
You can buy the RF modules by Robosoft Systems
RF modules which are based on Texas chip CC2500 and works on 2.4GHz
plus it provides you channel selection and device address selection option so that you multiple robots can communicate wirelessly and without any in interference.
http://robosoftsystems.co.in/roboshop/index.php/home/rf-module-for-wireless-communication.html

[virgo]

the modules similar to the HemantDJ mentioned is also available at tri(http://thinklabs.in/shop/product_info.php?cPath=67&products_id=185).These modules can support higher baudrate , these modules were designed for iitb nexus competitions.
i guess they are comparatively cheap than other wireless communication options.