eacastro
Newbie level 3
Hi all
I'm student and working with a small project which involves wireless transmission. I'm using the Parallax 433MHz Transceiver (OOK modulation, 2500 feet sight line) and have a problem during the transmission.
I'm using the UART from PIC16F876A with a baud rate of 2400 b.Initially the MCU is only in TX mode, while my PC is in RX mode (using Hyperterminal).
The MCU sends numbers as characters (0,1,2...).
I could receive succesfully this data in my PC, but only if the distance between TX and RX is around 20cms. If I exceed distance, the RX receives the characters but mixed with garbage characters.
I'vet tried differente baud rates (9600, 4800) but the problem is still the same, only works fine if the distance is 20cms or less, no more.
Datasheet says it works with 2500 feet.
I have no idea why I'm getting garbage characters over my strings.
This link is for the wireless transceiver:
**broken link removed**
My configuration is:
TX:
MCU (pin TX)----> RF Transmitter (pin Data, "TX/RX Sel" = High, this is TX mode).
RX:
RF Transmitter (pin Data, "TX/RX Sel" = Low, this is RX mode) --> MAX232---->RS232 PC
Thanks for your help/comments/suggestions.
I'm student and working with a small project which involves wireless transmission. I'm using the Parallax 433MHz Transceiver (OOK modulation, 2500 feet sight line) and have a problem during the transmission.
I'm using the UART from PIC16F876A with a baud rate of 2400 b.Initially the MCU is only in TX mode, while my PC is in RX mode (using Hyperterminal).
The MCU sends numbers as characters (0,1,2...).
I could receive succesfully this data in my PC, but only if the distance between TX and RX is around 20cms. If I exceed distance, the RX receives the characters but mixed with garbage characters.
I'vet tried differente baud rates (9600, 4800) but the problem is still the same, only works fine if the distance is 20cms or less, no more.
Datasheet says it works with 2500 feet.
I have no idea why I'm getting garbage characters over my strings.
This link is for the wireless transceiver:
**broken link removed**
My configuration is:
TX:
MCU (pin TX)----> RF Transmitter (pin Data, "TX/RX Sel" = High, this is TX mode).
RX:
RF Transmitter (pin Data, "TX/RX Sel" = Low, this is RX mode) --> MAX232---->RS232 PC
Thanks for your help/comments/suggestions.