MSP432P401R: UART communication problem

sayali pathak

Part Number: MSP432P401R

I am trying to Interface the SIM868 to MSP432 using UART.
I've set the UART baud rate as 9600 and DCO frequency is 48MHz and the clock source is SMCLK(12MHz).
I am transmitting "AT "and 0x0D command through putti software and checked response on Msp432. I got response "OK" in receive buffer of msp432which is but Initially data transmitt line is high which is checked on dso.
Now my problem is when I transmitt the same command "AT" and 0x0D through msp432 data is transmitted successfully checked on dso only difference is the data out line is initially low and I am not getting any response from sim868.Is there any specific bit to set for data out initially high in uart??? The data out pin of msp432 is initially low Is this the reason we can not write the data in sim868??
So please tell me what was the problem?

Many Thanks in advance.

over 8 years ago

0 Bob Landers over 8 years ago

TI__Expert 8510 points

Sayali,

I've run the uart_pc_echo_12mhz_brclk_MSP_EXP432P401R_nortos_ccs example and I see that the UART in idle mode drives the bus high.

There is no control to intentionally drive the bus low in Idle mode (else you couldn't generate a proper start bit). Can you try the above example and let me know if that behaves correctly (showing HIGH when idle between bytes)?

Also, could you post the code that you are using?

Regards,

Bob

0 Bob Landers over 8 years ago in reply to Bob Landers

TI__Expert 8510 points

Sayali,
Closing this thread since I did not hear back from you. You can still respond to the post if you'd like to pick it up again.
-Bob L

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MSP432P401R: UART communication problem