Interfacing 433MHz RF Module with PIC16F688

Thread Starter

Leonard Lim

Joined Oct 8, 2019
5
I am trying to interface the RF module which comes with Transmitter (FS1000A) and Receiver (MX-RM-5V) in pairs and interfacing with 2 sets of the circuit consists of 2 PIC16F688. After sourcing the internet, it seems like it can be interfaced either digital I/O or UART but I'm not sure about this. Is this possible to connect both of RF module in the following manner:

Transmitter side: Transmitter (FS1000A) - PIC1 (TX) [Not sure about the RX of PIC pin should be floating, grounded, shorted with TX or connect to Vcc (5V) since the transmitter only have 1 data pin]

Receiver side: Receiver (MX-RM-5V) - PIC (RX) [Not sure about the TX of PIC pin should be floating, grounded, shorted with RX or connect to Vcc (5V) since the transmitter have 2 similar data pin]

Sourced Baud rate - 9600

Please give some advice if anything is wrong in my statement and suggest some guidance. Thanks in advance.
 

SGuil

Joined May 12, 2020
3
Yes! Roman Black's page gives really accurate info on this topic. As he said, and contrary to many other opinions, a standard UART signal works well up to 1200 bauds (on most reasonable setups). 9600 doesn't. Rx on transmitter side, grounded or pulled-up. Tx on receiver, left floating.
 

BobTPH

Joined Jun 5, 2013
2,433
I have successfully used these modules with a PIC UART. But, in the end I used software UART because I could be more robust at rejecting spurious signals.

One trick I used was to require a solid mark signal for 10 bit times before trusting the transmitter. When the transmitter is off, the receiver reads high quite randomly, but, it appears that after seeing a strong signal from the transmitter, the receiver reduces its sensitivity. Then, during the space periods, no spurious signals are seen.

I am running at 1000 bps. It still has frequent errors and needs a robust protocol to avoid data errors.

Bob
 
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