I work with RF communication,using for that 434MHZ receiver and transmitter.I have problems,sometimes dont receive some messages that transmit and i have to send one more time.Anyone have this problem?Who i solve this?I lost data many times.
Hello,
The device receive corrupted messages, or no message at all?
For example i send a number and sometimes I have to send one more time to receive.
Are you using a library to handle the transmitting/receiving? Which one?
I do recommend using VirtualWire as it is well designed for these 434MHz on/off-keying radios.
Using a relatively low bit rate -- in the 1,000 to 2,000 baud range -- will increase reliability, versus a high (5Kbaud or more) rate.
Shorter messages are more likely to escape interference than longer ones.
Even in the best cases, messages are likely to be lost from time to time. 434MHz is used by a lot of things and interference from other applications in an urban environment is quite common. These cheap radios are not very sensitive or selective, and all sorts of interference can be picked up.
Thank you for the reply.
I use virtualwire.h library.
The transmitter:
http://www.inmotion.pt/store/rf-link-transmitter-434mhz
The receiver:
http://www.inmotion.pt/store/rf-link-4800bps-receiver-434mhz
This is the speed:
vw_setup(2000);
I have a wire antenna.
I dont know why lost so much data,i have to send sometimes one more time to receive.
Even with a correct design, losing 5% of your messages is entirely possible.
How far are your receiver and transmitter? Is this indoors or outside?
Are you in a lab or classroom with 12 other people also using 434MHz transmitters?
How many messages/minute are you sending?
How many bytes/characters in your message?
The transmitter and receiver are spaced more and less one meter,indoors.Im the only one on the lab.I send nine characters and lost data(sometimes dont receive).I test sending one character and de same problem.I imput the characters in to the serial.
Are the transmitter and receiver attached to the same ground -- eg: plugged into USB on the same computer?
I have encountered issues where reliability is terrible when the TX and RX ground planes are connected. I think the AGC on the receiver just can't handle the signal strength.
I have two arduinos, both plugged on differents computers.I think its a receiver problem(ground or Vcc problem)but i replace to a new one and the same problem.Any idea to fixs this?
Anyone have any idea to fix this?I use a breadbord to connect then and the arduino vcc and ground.
Radio communication is not 100% reliable, especially when using 434 Mhz , as its a shared frequency and you are competing
with anything else using the same frequency.
If you want 100% error free transmission, then you have to implement some kind of error checking or correction.
This means using 2 way communication between both ends to verify that the data is being received properly.
The problem is that 1 and 3 times dont receive data. I implement a error check and when receive data its receive properly.