Do you have the model numbers of the TX/RX pair?
To achieve 9600 BAUD you'll need to using an encoding/decoding scheme like Manchester. Without an encoding scheme you'll probably top out at 1200 BAUD.
Yes exactly, I got it from remote controlled car.I think its a 27MHz pair, ones i had seen in a toy remote car.
From where did u taken the demodulated data (in Rx) ?
If u could draw the circuit diagram of receiver then i think experts here could help U.
More over, i think u have to make it sure the connection u had taken from the receiver is the exact demodulated o/p.
What are the markings on the IC?
It's hard to tell by the photos, very blurry, what the pair may actually be.
The problem that this piece is available in my country with a price (in national cuurency) multipled by five of the price in dollars (due to the difference of currencies). I have seen rxtx pair over the net with about 15 USD, I can buy it here with about 85 L.EYou can pickup a 315/434 MHz Pair for just a few dollars if you want to experiment with RF/SubMHz data transmission.
The RX3 has only 2 keys with 3 states, i.e. forward key for forward function, backward key for backward function, and stop function if there is no signal.
... I thought that I can use them to connect tx of a micro to rx of another one wireless. I have a very limited knowledge about RF and wireless circuits, but I was having some doubts that both of RF transmitter and the receiver are not designed for the purpose I want. When I gave it a try, nothing worked as I supposed. I was working on baudrate of 9600, but I thought that if I lowered the baudrate greatly, this could solve the problem. I reached with the baudrate even to 19, but nothing worked !! When the micro starts to send by tx, the RF receiver goes high and I read voltage on its output (which means it does receive the signal), but the micro does not understand it. I tried to put a 33pf capacitor parallel with rx receiver to filter the signal, but nothing worked.
I think the receiver circuit is similar to what exists in ic datasheetOR u should some how draw the circuit and post it here so that many analog circuit designers and experts in this forum could help U.
Maybe by analogy to the way pulsed IR is used, mamech could pulse the encoder frequencies (forward = 1KHz; reverse = 250 Hz) and use the detected pulse widths at the forward (pin 11) or reverse pin (pin 8 ) for two channels of data. In a very simplistic application, for example, a pulse width of 1 mS would be a "0" and 2 mS would be a "1". A more practical approach would be to use Manchester or other similar-purpose encoding.
As an alternative, pin 11 pulses would be "1" and pin 8 pulses would be "0."
Here's a link to the Embedded Wireless Network group's list on Manchester encoding/decoding:
John
Hi John,
Well that is certainly a novel idea and doable.
However, with frequencies of 1K/250 Hz it's going to be a painfully slow baud rate.
Send your commands and grab a cup of coffee slow!
What did you use to test the RF connection, PC, MCU, etc? And exactly how did you make the connection?
I have some questions:
1-I understand from your previous post that sending UART directly is not possible in this situation, but I should use Manchester. Have I understood you right?
2-There is a library for Manchester code in MikroC (the complier that I work with), but I found that there is a note in the library:
"Note : Baud rate used is 500 bps. " So does this mean that I cannot use it in this application , because the baudrate must be either 1000 or 250?
3-If used Manchester coding, should I get the output from receiver from 11 or 8 ?
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