Tracy Chin
Newbie level 4
Hi, I am doing school project and have encountered a problem when using T5/R5 module and PIC16F877 USART feature for RF communication.
Datasheet for T5/R5 module and my schematics are attached. Basically, the route is T5 Tx pin -> PIC Tx -> transmission media -> R5 Rx pin -> PIC Rx. I didn't use any encoder/decoder related chip.
When I directly connected PIC Tx to PIC Rx, the circuit worked. However, after I added RF modules, the communication between two PIC failed. I observed the wave in oscilloscope. When a signal was sent from Tx, a similar shaped signal was received from Rx. But when nothing was sent from Tx, noises presented in Rx (I saw waves up and down in high freq). That may be why PIC failed to interpret the meaningful signal I sent.
The baud rate I use is 4.3Kbps. Anyone has the idea about what the problem is? Shall I change the capacitor value or baud rate? Many thx.
Datasheet for T5/R5 module and my schematics are attached. Basically, the route is T5 Tx pin -> PIC Tx -> transmission media -> R5 Rx pin -> PIC Rx. I didn't use any encoder/decoder related chip.
When I directly connected PIC Tx to PIC Rx, the circuit worked. However, after I added RF modules, the communication between two PIC failed. I observed the wave in oscilloscope. When a signal was sent from Tx, a similar shaped signal was received from Rx. But when nothing was sent from Tx, noises presented in Rx (I saw waves up and down in high freq). That may be why PIC failed to interpret the meaningful signal I sent.
The baud rate I use is 4.3Kbps. Anyone has the idea about what the problem is? Shall I change the capacitor value or baud rate? Many thx.