Please look in to the attached link that shows 433Mhx RF-transmitter-and-receiver
I have decided to use this RF-transmitter-and-receiver for remotely control my robot
Could you please advice me what are the problems that I have to face when I connected it to directly to USART of PIC 16f877a ( Rx and Tx of PIC )
and what could be the benefits if I connect between PIC and RF-transmitter-and-receiver suitable decoder
I also bought a pair of the same item and seller!!
I will use CCS and PIC serial communication.
The place where I will use is not critical!!
No interference in this frequency range!!
Here the band is widely used in gate controls and alarms!!
If I have problems, just increase a wire coil in redesigning the TX and RX (I have experience with this tx, because he worked with layout).
My items have not arrived yet so I can do the program and test.
While transmitting/ receiving directly from the controller you need to have controllers on both the side (at Rx & Tx sides) because Rx side controller need to be have 8-N-1 (or whatever frame you use) type frame structure at some precised baudrate ! This could be the problem in noisy area!
Benefit to use encoder/decoder is that we need not to have any controller on either side. But if our application have controllers on both the side then this benefit can be taken as money loss.
So it depends on our distance between Rx & Tx and on application whether we need controller both the sides or not!
As it is a 3.3 V ot 5 V device its DATA pins will be TTL/CMOS level. Mention the model no. of your Rx and Tx modules. If you have a datasheet for it then post it. Usually they connect to Serial Port.
If they give TTL/CMOS level outputs then you can connect it to USART pins. Does the module you mentioned has two DATA pins?
Edit: This is the modules mentioned in the link you provided. MX-05V and MX-FS-03V. Tthe MX-FS-03V works from 3 - 12 V. You should provide 5V. The link also provides sample code.
The communication pins work at TTL levels and so you can connect it to UART pins of MCU directly. If you want bi-directional communication you have to use two RxTx module pairs.
How much did you pay for it? I bought the same from MiniInTheBox.com. It was quite cheap and there was free shipping.
Antenna side facing you means... right-most pins of both modules is GND, left-most pins of both modules id Vcc, middle pins are DATA pins. The DATA pin of Tx (small module) goes to Tx pin of MCU. The DATA pin0s) of Rx module (bigger module) goes to Rx pin of MCU.