RF Wireless Module -- Problem

[sakaz]

kxd10036 transmitter module

Dear Fourm,

HOpe you are all doing well.

I have just received few RF Modules 315MHz they are chinese made so i am not interested in these things but i am so much curious to work with the RF data link for my few projects. But i am bit confuse to use the transmitter because of there is not mentioned any pinouts. I have googled and found the module KXD10036 at:

**broken link removed**

**broken link removed**

The receiver module is KXDJS2025 it mentioned the pinouts but how would i know pinouts on the Transmitter Module (VCC, GND, DATA, ANT).

I have searched on the website and consider the TLP434A and RLP434A the pinouts are almost same for the receiver as i have. Could you please confirm me all Transmitter ASK module mostly has same pinouts. I am confuse to apply voltage and avoid any damage.

Can you tell me how i can check the Transmitter is working or not without receiver.

Regards,

Shan

 

[rupesh]

kxd10036 rf module

Do you have a spectrum analyzer....? u can check variation on that by setting you transmitting frequency ... or you can check by CRO after designing a simple reciever same as your transmitting frequency ...

 

[junior_naik]

i want little help plz help me.
i am using transmitter tlp434A and receiver rlp434 with AT89c51 at receiver's and at transmitter's end as well .i want to transmit (just testing) digit 18 SERIALLY (converted to ASCII,from binary).when i conect the TXD pin of MCU (at transmitter's end) with the Rxd pin of mcu (at receiver's end).it perfectly transmit didgit 18 and is displayed on lcd perfectly but when i tranmit it by using tlp434 with rlp434 receiver,so digit is not displayed on lcd but i can see only cursor

note tht i connected the txd of mcu to the data in of transmitter directly,at transmitter's end and the data out (digital),of receiver ,i connected to mcu's rxd pin at receiver's end.
kindly help me

 

[rupesh]

you can try by reducing boudrate, as such as possible.

 

[junior_naik]

brothr i reduced boudrate to lowest but it is not working plz help me

 

[wp100]

Hi,

Are you using the Manchester encoding in your transmit and receive routines?

Without it, the receiver will be flooded by all the others signals on the airwaves.

 

[junior_naik]

no brother i am not using manchester encoding,actually i dont know how to do manchester encoding/decoder plz help.i downloaded rlp_tlp_8051_1331.zip file and connected the circuit according to it but no thing happen but i am receiving garbage .plz tell me about manchester encoding /decoding.. how can i learn it?

 

[wp100]

Hi,

Only use the PICs so do not know about the 8051 software.

Manchester encoding is not a routine to write yourself, you need to search for some ready made example.

Basically it sends a unique address with each burst of data and your receiver is also programmed to only accept data with the correct address so all the other rubbish transmissions are rejected.

The 8051 might use some similar but differently named encoding method ..?

 

[ctownsend]

You can do any kind of encoding you want as long as
a, the bit period is not too fast for these cheap modules
b, the timing is exact for both RX and TX which means very critical
timing routines you should do with assembly
NOT C.

The biggest problem is the decoder timing. This is where most guys run
into problems. Synchronizing, or detection of the start bit is the
main problem.

I was successful in making the start bit(s) twice the bit period as
the data bits. The decoding routines must be able to measure the bit
period and ignore the data if the bit period of the start bit(s) do
not match. This can be done many different ways, using input capture,
timer overflow, or whatever you choose.

If you are a beginner, this is not a project for you. I HIGHLY doubt
you will EVER find example source code that uses any kind of
sophisticated encoding, especially for the 8051!

You will find code that uses the MCU's uart but it will never be 100%
reliable. If you must use the uart, or only have a few pins, go for a
better wireless module that accepts serial data and does the decoding for you.
They may cost a little bit more, but you will save hours,days,weeks, months of
your time. Is your time worth the little bit of extra money?

If you absolutely MUST use a cheap wireless module with no hardware
encoder/decoder chip, be prepared to learn a great deal about MCU
timers, input capture, manchester encoding/decoding.

The easiest wireless modules I have used with an 89C51 are the
nrf2401a.
All you do is bit-bang spi packets and the module takes care of
encoding/decoding, and works up to 150 feet away. These modules work
with 3.3V. I have a successfully running system using an 89C51 at 3.3V
even though it is running under spec.

There are even easier modules you can use, just do some searching. Sparkfun has many wireless products.

If this is a homework project, Good Luck!

 

[junior_naik]

its a part of my final yr project(industrial fire fighting robot). I wana ask some qz↲1.i hav to transmit 8bit data can i use ht 640 nd ht 648 encodr/decodr? Aftr using these chips would i gt my data clrly with out any garbage?↲2.in my projt i m using INT0(TO sense obstacle).can i use p3 to send data nd to dtect obstacle.nt at the same time coz whn my car wud mov for 4s forwrd it wud nt be transmiting any thng.or could u tel me any othr solutiön to adjust both .the chips nd obstacle sensing mechanism in my ckt .i hav 2 pins remaing in port 1

 

[ctownsend]

Is it mandatory that you use these cheap modules with an ht640 pair? Why not use this one?
XBee 1mW Chip Antenna - SparkFun Electronics

 

[junior_naik]

XBee 1mW Chip Antenna CAN THIS MODULE RECEIVE ALSO?? I MEAN THT I HAV TO BUY TWO MODULES ONE AS TRANMITTER AND OTHR AS THE RECIVER?? ACTUALLY ITS DEFICULT TO GO FOR THESES MODULES COZ I ALREADY BOUGHT TLP/RLP MODULES.

PLS REPLY TO MY THIS QUESTION
i hav to transmit 8bit data, can i use ht 640 nd ht 648 encodr/decodr? Aftr using these chips would i gt my data clrly with out any garbage?????

 

[ctownsend]

XBee 1mW Chip Antenna CAN THIS MODULE RECEIVE ALSO?? I MEAN THT I HAV TO BUY TWO MODULES ONE AS TRANMITTER AND OTHR AS THE RECIVER??

Read the datasheet. If you are a student you are going to have to learn to read the datasheet every time. To answer your question, yes you will need two. One as TX and one as RX. These units can RX and TX. Using these units will make your life easy as they handle all of the encoding/decoding.

ACTUALLY ITS DEFICULT TO GO FOR THESES MODULES COZ I ALREADY BOUGHT TLP/RLP MODULES.

PLS REPLY TO MY THIS QUESTION
i hav to transmit 8bit data, can i use ht 640 nd ht 648 encodr/decodr? Aftr using these chips would i gt my data clrly with out any garbage?????

I don't know where you will find the HT640, they are obsolete. YES, you can transmit 8 bit data without garbage if the code is written correctly. AGAIN, read the datasheet before you start.

 

[junior_naik]

thnks.brthr my code is correct .its simply convrts binary tmp to ascii and transmits.i chked it in proteous and in hrdware ,whn i cönectd the tx and rx of mcu(s) by wire ,its wrking prfectly.ok i wil read the data sheet.i wana ask sum thng .if i dnt find Ht640 pair , how wil i be able to trnsmit nd receive 8 bit data using 4 data lines of Ht12e pair?↲othr thng i wana share with u tht in ordr to gt ride of grbage at receivr's end wt i did ,i stored 17 values of tmp and wt evr i receive i xor it with al values stord in the memory and if the received value is = to the stord value so it wil be printed on lcd othr wise proces wil restrt.code is perfectly wrking in proteous bt nt whe i use it with hrdware.öne thng more tht whn i cönnt the modules and if i trn of the tx module ,yet the rx keep on prnting garbage on lcd could u tel me y?

 

[ctownsend]

how wil i be able to trnsmit nd receive 8 bit data using 4 data lines of Ht12e pair?&#8626

send one nibble at a time.
for example:

byte to send is in acc.

	push acc
	swap a		
	anl a,#0Fh
	mov p1,a
	clr TE
	setb TE
	pop acc
	anl a,#0Fh
	mov p1,a
	clr TE
	setb TE

 

[nikhilele]

.i hav to transmit 8bit data can i use ht 640 nd ht 648 encodr/decodr? Aftr using these chips would i gt my data clrly with out any garbage?

they work perfectly

---------- Post added at 05:01 ---------- Previous post was at 05:00 ----------

they are available in sp road bangalore

 

[junior_naik]

thanks broth nikhilele ,bt i live in pk
@ctownsend
brother i wana share with u some stuff,actually i am nowadays writing code for receiving the transmitted (4bit data ,as u taught me).i wana share my strategy ,,at receiver side wt i would do,having prepared the lcd to display data i would use polling method to chk the VT pin if it goes high thn i would call receive function and after displaying the control would be returned to polling position..
onething more for example if i change the transmitter ,wt would be best for me? the one u told me or any othr ,as u know tht i hav to transmit temperature and fire status (fire sensed or no fire etc) 8 times in a minute.

 

[ctownsend]

use polling method to chk the VT pin if it goes high thn i would call receive function and after displaying the control would be returned to polling position

yes. poll VT then read the byte from the port.

When reading the port, mask off the high nibble using the anl instruction as I mentioned before, as the high nibble of the port will be meaningless. (that is if your decoder is connected to the low 4 pins of a port) You may want to send a start byte so that your TX and RX are in synch. For example, send command 0fh (all 4 bits high) to indicate start byte. Then you know the next byte will be high nibble, and the following byte will be low nibble.

onething more for example if i change the transmitter ,wt would be best for me? the one u told me or any othr ,as u know tht i hav to transmit temperature and fire status (fire sensed or no fire etc) 8 times in a minute.

?
Change the transmitter? You mean buy the Xbee modules?

 

[junior_naik]

ya thts wt i meant