UART Question

[Spadez]

Hi.

I was just wondering. If I have a RFID module which uses a UART and a MP3 board which uses Uart too, is it possible to use a PIC which only has one uart.

This might work by the RX uart connecting to the RFID module since I think that only sends data to the PIC and doesn't receive anything. The MP3 module on the other hand receives commands from the PIC using the TX, but doesn't send anything back, so doesn't require a RX.

Using a single TX and RX combination is it possible to interfaces two UART devices with one PIC uart? If yes, do they have to have the same baudrate for devices on TX and RX?

Thank you.

James

 

[blueroomelectronics]

What are the baud rates of the two devices?

 

[Spadez]

Hi,

Its 9600bps

 

[Wilksey]

You can if you have the same baud rates and you can differentiate between the protocols.

Given up on the PIC with 2 UARTS idea?

 

[Spadez]

Not entirely, but I thought this might be an elegant solution. The truth is my knowledge is limited so im not sure what would be best.

RFID: 9600bps TTL and RS232 output
https://www.sparkfun.com/products/8419

MP3: Serial: Full duplex, 8N1, 38.4K baud (9600bps fireware apparently availiable)
https://www.sparkfun.com/products/9715

What would you say is there better route?

 

[Spadez]

Ive been reading up on this. Is it reasonable to say that this will work if the following conditions are met:

1. Both RFID and MP3 modules are only one way communication
2. Both have the same baud rate
3. Both use the same protocol? (Does this mean 8N1, full duplex etc?)

I know i asked about pics with two uarts but this would be a perfect solution if it was possible.

 

[Wilksey]

1) You can have 2 way communication if the protocols are different.
2) Yep
3) The serial protocol, so this is the "control codes" etc to make the units do certain things, like you may send "00 01" to play an MP3 for example,and send "00 01" to read an RFID card, this would be the same kind of protocol.

 

[blueroomelectronics]

Should work fine, although the baud rate is shared the RX & TX are separate modules.