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Topic: RF Transceiver problem (Read 1 time) previous topic - next topic

roboKid

Hi, all
I'm new to arduino and robotics, i have a low cost RF transmitter (434 MHz) and Receiver pair.And i'm using HT12E and HT12D pair for error handling. i've Connected PC serial port's TX pin to AD8 pin of HT12E and HT12D's D8  to arduino RX(pin 0). All i've to do is send some msg from the computer(stream of chars) serially to the arduino ,but i'm not able to do this. I've adjusted the baud rate to less than 100bps,but still no result .I've given same voltages at receiver and transmitter ends. I've enabled transmission by driving TE low on HT12E . The VT(Valid Transmission) on HT12D is never high. Am i doing this correctly or are there any other factors that must be considered. Please Help.
Thank you :)

PaulS

Now that you have made your first post, you can post links. Please do so, for the transceivers that you have.

A sketch of how you have them connected would not be a bad thing, either.

roboKid

Here is the link

http://www.botskool.com/tutorials/electronics/general-electronics/building-rf-remote-control

I've connected pretty much in the same way given in the link above.

PaulS

Quote
I've connected pretty much in the same way given in the link above.

"Pretty much" and "Exactly" aren't the same thing. In electronics, "Exactly" is required unless you know what you are doing.

PaulS

@Richard
OP did say that one end of the chain was an Arduino. That pretty much qualifies for posting here.

Unlike some posters who seem to think that having once heard of an Arduino is reason enough.

roboKid

@richard i'm using HT-12 pair for handling errors that may occur during transmission. i want to know whether i can connect the DOUT from receiver directly to RX (pin 0) in arduino.

@paul i've told it as "pretty much" because my application(Wireless Data Transfer) is different from what is given in link(RF remote Control).

roboKid

@Richard Thank u for ur reply.

I just want to know if there's any library or functions built into Arduino IDE for error handling .

And links to projects similar to mine would be helpful :)

Boffin1

#7
Nov 08, 2010, 05:42 pm Last Edit: Nov 08, 2010, 05:44 pm by John_Smith Reason: 1
you can try the virtualwire library, that has error checking I seem to recall when I looked at it...

The HT12 error checking is by repeating the code several times and checking if they are identical, the whole address and code, it works well for my projects over the last 10 years, but it is so slow !

roboKid

The project consists of a robot/set of robots which actively take commands and messages from PC wirelessly through RF and then process the data received and carry out the operation as required.And i want to extend this to web also wherein it'll take requests from web portal also :)

roboKid

#9
Nov 08, 2010, 07:24 pm Last Edit: Nov 08, 2010, 07:25 pm by sashank1989 Reason: 1
@boffin Thanks for the reply
i want to use Arduino's built in UART capabilities to the max.Virtual wire does this by taking digital pins for I/O


i want to know 1 more thing, if i use a transceiver module instead of just a transmitter or receiver at both the ends,will i be able to upload the programs to the board, some thing like "on the go program upload" , that would be interesting. :)

roboKid

#10
Nov 08, 2010, 07:47 pm Last Edit: Nov 08, 2010, 08:18 pm by sashank1989 Reason: 1
if the msg length is < 500 bytes and it is transmitted in bursts with average interval of < 2sec. which error handling mechanism would be suitable.

PaulS

Another factor, that you haven't defined, is how critical loss of data is. If you are sending data to control the color of an RGB LED, and one packet get lost/corrupt, it probably isn't worth the effort to communicate that fact back to the sender, and request re-transmission.

roboKid

So u would prefer some Checksum(CRC) or Parity Checks(Hamming Code) for this kind of application ?

roboKid

Ok i understood. Thank you.

i want to know 1 last thing

Quote
if i use a transceiver module instead of just a transmitter or receiver at both the ends,will i be able to upload the programs to the board, some thing like "on the go program upload"


is this possible? if yes, how? :)

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