topic Re: RT1015 LPUART_TransferReceiveNonBlocking Driver in i.MX RT Crossover MCUs

RT1015 LPUART_TransferReceiveNonBlocking Driver

kensu — Thu, 04 Jun 2020 02:21:58 GMT

Hi,

I am study UART with "evkmimxrt1015_lpuart_interrupt_rb_transfer" SDK sample code.

The sample code is no problem.

After I modify some flow, it cannot receive any byte,

My idea is using polling to call LPUART_TransferReceiveNonBlocking, if get any byte, use tx send a debug log.

I don't know why this modification cannot receive any RX byte.

Maybe there are some constrain to using LPUART_TransferReceiveNonBlocking?

I attached the source code. I only modify this file.

Can someone give me a hint?

Regards

Ken

Re: RT1015 LPUART_TransferReceiveNonBlocking Driver

jeremyzhou — Thu, 04 Jun 2020 08:19:46 GMT

Hi Ken Su,

Thank you for your interest in NXP Semiconductor products and
for the opportunity to serve you.
Firstly, you should move the function :
LPUART_TransferReceiveNonBlocking(DEMO_LPUART, &g_lpuartHandle, &receiveXfer, &receivedBytes);
out of the While(1) {} loop, then using the LPUART_UserCallback () fucntion to handle the signal value which will determinate whether call LPUART_TransferSendNonBlocking(DEMO_LPUART, &g_lpuartHandle, &sendXfer); or not.

Have a great day,
TIC

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Re: RT1015 LPUART_TransferReceiveNonBlocking Driver

snahmad — Mon, 04 Jul 2022 13:49:57 GMT

Any idea to how to bytes actually read from LPUART_TransferReceiveNonBlocking

Re: RT1015 LPUART_TransferReceiveNonBlocking Driver

snahmad — Mon, 04 Jul 2022 18:00:12 GMT

LPUART_TransferReceiveNonBlocking, I do get call back which rxcomplete, but I cannot how many bytes read.

Re: RT1015 LPUART_TransferReceiveNonBlocking Driver

snahmad — Thu, 07 Jul 2022 14:51:45 GMT

Hi all,

I manage it make it work using Rx Interrupt handler for every character which tell me count bytes received on LPUART Rx.

Solution 1-

For that I use LPUART2 for Tx using non-blocking LPUART_TransferSendNonBlocking which works anyway.

For Rx I am not using non-blocking LPUART_TransferReceiveNonBlocking

For Rx I am using LPUART3 with my own interrupt handler for every char received.

See my solution file : lpuart_rx_interrupt.c

Solution 2-

Solution # 1, but is not efficient as it is not using DMA.

Can some one elaborate why LPUART_TransferReceiveNonBlocking using with ring buffer does not give us bytes read.

Does using LPUART_TransferReceiveNonBlocking with ringbuffer use DMA method.

See my example code attached: lpuart_ring_buffer.c, not tell me how many bytes it received.

however data do get received in buffer=g_rxBuffer not in g_rxRingBuffer

Thanks,

Syed