uart_tx api crashing issue

[PingISTL]

Hi, All

I try to modify the central uart example - mainly focus on uart function instead of BLE, I try to send a message back to uart use uart_tx() api instead of printk(), it seems working fine like this

 

    struct uart_data_t *buf = k_fifo_get(&fifo_uart_rx_data, K_FOREVER);
    
    if (uart_tx(uart, buf->data, buf->len, SYS_FOREVER_MS)) {
		LOG_WRN("Failed to send data over UART");
	}
	else {
		LOG_WRN("send data back to UART");
	}

But when I try to replace the uart_tx function with some message like below, and it keep crashing - reset

   

	uart_tx(uart, "UartDataRxed\n", 13, SYS_FOREVER_MS);

I wonder what I have done wrong with above, here is the RTT log message:

0> [00:00:00.025,787] <err> os: ***** BUS FAULT *****
00> [00:00:00.025,787] <err> os: Precise data bus error
00> [00:00:00.025,787] <err> os: BFAR Address: 0x2528206c[0m
00> [00:00:00.025,817] <err> os: r0/a1: 0x2528206c r1/a2: 0x00027b50 r2/a3: 0x20002300
00> [00:00:00.025,817] <err> os: r3/a4: 0x00000040 r12/ip: 0x00000000 r14/lr: 0x0001e533
00> [00:00:00.025,817] <err> os: xpsr: 0x21000012
00> [00:00:00.025,817] <err> os: Faulting instruction address (r15/pc): 0x0001e820
00> [00:00:00.025,848] <err> os: >>> ZEPHYR FATAL ERROR 0: CPU exception on CPU 0
00> [00:00:00.025,848] <err> os: Fault during interrupt handling

Thanks for your help!

Ping

[AHaug]

Hi Ping,

The string you're trying to pass is not of length 13, but rather it is length 14. Try to change it to 14 and see if it works!

If it does not work, I would recommend you take a look at this NCS Course topic concerning UART to both read up on the essentials as well as examine if the sample in exercise 1 could explain what you're missing. Additionally, this uart echo sample might be of help

Let me know if any of this helps! 

Kind regards,
Andreas

[PingISTL]

Thanks for reply, Andreas

here is what I did, and cannot go any further - did I misunderstand you?

Ping