UART + TIMER

[khairul]

Hai, i re-post this problem... i have a problem regarding with UART and TIMER, i have a code to transmit a serial data to a module and wait for the module to return a packet of data back if any, else leave the task..

My problem is the coding just wait forever until the packet of data received to the pic due to this coding line

CODE: SELECT_ALL_CODE

while(PIR1bits.RCIF==0); //wait for data to received


and i just want it to wait for a while, if there is no data then leave from the task.

So my solution (if it is possible) is to ON a TIMER to wait for a while and AT THE SAME TIME waiting for the packet of data to be received. If the timer is off, just jump back to the main.

So it is possible to create code like that? or there are other solution that im not aware of.

[shahrul]

Hai, i re-post this problem... i have a problem regarding with UART and TIMER, i have a code to transmit a serial data to a module and wait for the module to return a packet of data back if any, else leave the task..

My problem is the coding just wait forever until the packet of data received to the pic due to this coding line

CODE: SELECT_ALL_CODE

while(PIR1bits.RCIF==0); //wait for data to received


and i just want it to wait for a while, if there is no data then leave from the task.

So my solution (if it is possible) is to ON a TIMER to wait for a while and AT THE SAME TIME waiting for the packet of data to be received. If the timer is off, just jump back to the main.

So it is possible to create code like that? or there are other solution that im not aware of.

In the PIC there have a lot of Interrupt. Some of that UART Interrupt and Timer Interrupt.
So, this case no need Timer, just use UART Interrupt.

[khairul]

i have read the datasheet, RCIF is a interupt flag that set when received buffer is full. so in my coding below,

CODE: SELECT_ALL_CODE

while(PIR1bits.RCIF==0); //wait for data to received

the "while" will wait until the received buffer is full, but i don't want it to wait forever because i know that sometime the module will not give data back although we have send some data to it.

it is exist an interrupt that trigger when there are no data received at the RX?


bit 5 RCIF: EUSART Receive Interrupt Flag bit
1 = The EUSART receive buffer, RCREG, is full (cleared when RCREG is read)
0 = The EUSART receive buffer is empty

[shahrul]

oh, but how do i get out from the code

CODE: SELECT_ALL_CODE

while(PIR1bits.RCIF==0); //wait for data to received

it is exist an interrupt that trigger when there are no data received at the RX?

See this example http://forum.cytron.com.my/viewtopic.php?f=21&t=12129#p22954