[SOLVED] 433Mhz RF module problem

[jayanthyk192]

Hi,

I'm working with a 433MHz TX abd RX. Its a simple ASK module witk OOK. The problem:

i switch on the reciever and then press a button on the TX which transmits the signal. I get a 5V on the data line of the RX. If i switch off the TX, the RX gives a 0V. This happens for a few seconds. Then on, even if i dont press the button, the voltage reading is at around 2.5V DC and 2.5V AC. If i press the button I get 5V, else its this AC+DC mix. So what do i do.

Actually, i had the same problem a few monts ago and i thought the reciever was spoilt, but this is a new one and gives the same problem.

Please help.

 

[upand_at_them]

Some of these modules are prone to noise. You need to be transmitting data for them to work better. That is, don't just transmit a high or low and leave it in that state. The transmitter should send a starting byte that the receiver recognizes, then your data, and then an ending byte. It helps if the starting and ending bytes don't occur in the data bytes.

 

[aameer]

i think it is because of floating value.you should design in such a way that it should transmit either 5v or 0v

 

[upand_at_them]

Some modules may require a pullup resistor on the data line, but I don't think these ones do. He'll need to check the datasheet.

 

[jayanthyk192]

Some of these modules are prone to noise. You need to be transmitting data for them to work better. That is, don't just transmit a high or low and leave it in that state. The transmitter should send a starting byte that the receiver recognizes, then your data, and then an ending byte. It helps if the starting and ending bytes don't occur in the data bytes.

You're absolutely right. I directly connected it to my MC and serial port(RS232) of my comp. I sent a few characters and it worked fine. When i send a 1 the output at the receiver is 1 but when i send 0 (or switch off the TX module), there is a lot of noise. But as you said, if i send continuous data it'll be giving proper results.

Thank you for the help.