Handling two different UART device with one port

[majidkhalili]

Hi guys
i dont know if this is the best place ask this , so if i have to post it in different section pls let me know
i have an avr micro controller that is working with PC using one of its serial port , and the avr has only one other serisal port , and i need to work with tow different device using UART , i have know idea what can i do
one of the devices i'm just reading from , and another one i'm bot reading and writing
and the important thing is that for both these devices i have to use the interrupt , so i cant not use just simple mux to handle these to , because they should interrupt the avr to read the value of them , so with mux i migh lose the data

pls tell me any thing that can help
thanks

 

[ftsolutions]

Do you have enough I/O pins on the AVR to attach an external UART IC? If not enough for a parallel interface, you can connect an external UART IC which uses I2C interface (only 2 pins for clk/data and up to 3 more pins for control, reset, and IRQ). One possible IC for this would be MAX3107

 

[Venkadesh_M]

use software uart or hardware multiplexing...........

 

[mathespbe]

use MUX for Tx and Rx pins... With ISR you can easily handle Tx and Rx by means of mux...

 

[majidkhalili]

use software uart or hardware multiplexing...........

i dont know what is software uart ( does it mean it doesn't need hardware interface and i have to implement the timing and those thing on software ?!!!!! because thats really difficult i think )
and how is hardware multiplexing ? i have know idea

- - - Updated - - -

Do you have enough I/O pins on the AVR to attach an external UART IC? If not enough for a parallel interface, you can connect an external UART IC which uses I2C interface (only 2 pins for clk/data and up to 3 more pins for control, reset, and IRQ). One possible IC for this would be MAX3107

wow two thing :
1. is there any parallel to UART IC ? really , thats nice because i have enough pin for that , but can i handle the interrupt too or not ? and do u know any part number for them ?
2.as i understood MAX3107 is a I2C to UART converter with data buffer and such thing , is that true ? if i decided to use that i think i have to use pooling instead , and i think it may cause a good system design,i mean it might get complicated both in hardware and software , or may be i'm thinking in bad way , so if there is any block diagram u can post that would be really appreciated

- - - Updated - - -

use MUX for Tx and Rx pins... With ISR you can easily handle Tx and Rx by means of mux...

sorry whats "ISR" ?
is that interrupt Service routine ?!!
do u have any block diagram to suggest for system design ?

 

[ftsolutions]

IF you have alot of pins available to do a parallel bus UART, you can get a dual UART - just google ST16C2552. For the datasheet on the Maxim MAX3107 I2C/SPI interface UART, just google "MAX3107". Either of these parts has an INT pin to signal to your micro that it needs servicing.

 

[majidkhalili]

yeah , i think i go with avr ATmega 1280

 

[jayanth.devarayanadurga]

CD4066, 74HC14...

https://www.microchip.com/forums/m641943-print.aspx
https://www.societyofrobots.com/robotforum/index.php?topic=6283.0
https://www.ti.com/lit/ds/symlink/cd4066b.pdf

https://en.wikipedia.org/wiki/Analogue_switch

 

[mathespbe]

yeah , i think i go with avr ATmega 1280

Yes ATmega 1280 is having 2 USART... make sure you are using max utilities of the uC for your project...