[SOLVED] Dual UART. Is there anything to be added to the circuit?

[jayanth.devarayanadurga]

Dual UART. Is there anything to be added to the circuit?

 

[milind.a.kulkarni]

Hi Jayanth,

I went through your folder but could not able to see any schematic file.... there is DNS and Hex file..... I think you are using Orcad.....Unfortunately I don't have that software.... If possible post .pdf file such that one can see and comment....

With regards,

Milind

 

[Venkadesh_M]

Hi the bilateral switches are costly, use mux instead and in this scheme, its works fine but its better pull up the switch outputs...

 

[jayanth.devarayanadurga]

Thnak you for the replies.

@ milind

The .dsn file is Proteus ISIS file. I am posting the schematic in image format. I am attaching the UART project files also. I will try with pullups in real hardware.

 

[betwixt]

RD0 will switch from one UART path to the other but bear in mind that you can't use both together. If data arrives on the disabled path it is lost forever, it won't wait there until you select it again.

If you need to use two UARTs simultaneously, there are three options:
1. Use a PIC with two UARTs built in to it,
2. Use the existing UART and add a 'soft' UART. That is, one emulated in software.
3. Add an external UART, take a look at the MAX3100 for example.

Brian.

 

[jayanth.devarayanadurga]

Thanks betwixt. In my project data doesn't come for two UART at the same time. Data is received/sent from/to UART1 and then depending upon data received data is sent/received to/from second UART.

 

[milind.a.kulkarni]

As I understand your circuit .....you are using single RX Tx multiplex using one signal .... This should work but you will not get two UART signals simultenously ......generally RX from UART are asynchronous in nature ..... Your application forces the in this situation to be predicable.... Such that you can have that mux to be enabled ..... My suggestion here will be go with chip with two independent UART ......

Good luck