ChibiOS Free Embedded RTOS

Hi,

there is some strange problem with sequential calls of uartSendTimeout: 3 calls of uartSendTimeout sequentially, last call will send 0xFF instead of real data, if use debugger and step over 3 calls each sends correct data.
ChibiOS 17.6 and STM32L011x4

ps.
What is the difference between uartSendTimeout and uartSendFullTimeout, uartSendFullTimeout sends successfully data and constantly returns TIMEOUT

Hi,

uartSendFullTimeout() waits for the data to be entirely sent, uartSendTimeout() just waits for data to be placed in the data register but transmission is still ongoing.

Giovanni

Hi,

thanks for reply!

Addition note: ChibiOS NIL 17.6.

Is it necessary to wait something after call uartSendTimeout and returning for it with result MSG_OK and number of frames equals to value passed to uartSendTimeout?

Is there any reason why uartSendFullTimeout can send successfuly data over UART and returns MSG_TIMEOUT?

Test case:

1. Sending 3 bytes using uartSendTimeout, result MSG_OK, *np == 3, Logic Analyser result: ok
2. Sending 12 bytes using uartSendTimeout, result MSG_OK, *np == 12, Logic Analyser result: ok
3. Sending 2 bytes using uartSendTimeout, result MSG_OK, *np == 2, Logic Analyser result: one byte 0xFF

Hi,

The function should never return MSG_TIMEOUT unless there is some HW handshake enabled that can slow down transmission. Moving this topic in "bug reports" or it would get lost and forgotten.

Giovanni

Hi,

UART config:

UARTConfig portUartConfig = { .txend1_cb = NULL,
.txend2_cb = NULL,
.rxend_cb = NULL,
.rxchar_cb = NULL,
.rxerr_cb = NULL,
.timeout_cb = NULL,
.timeout = 0,
.speed = 9600,
.cr1 = 0,
.cr2 = 0,
.cr3 = 0
};

Hi,

this test case works fine (HW view) except MSG_TIMEOUT in 3d step:

1. Sending 3 bytes using uartSendTimeout, result MSG_OK, *np == 3, Logic Analyser result: ok
2. Sending 12 bytes using uartSendTimeout, result MSG_OK, *np == 12, Logic Analyser result: ok
3. Sending 2 bytes using uartSendFullTimeout, result MSG_TIMEOUT, *np == 2, Logic Analyser result: ok

What is the timeout you specified in uartSendTimeout()?

Giovanni

Now it is 300ms, it was 2000ms with the same result

uartSendTimeout(sprodp->uartDriver, &n, message->buf, MS2ST(300))

I tried to add threadSleep (10 - 20ms) between step 2 and 3 but it did not help.

It looks like the DMA stops sending data to the UART so the function is blocked until the timeout happens (the caller thread is woken by a DMA IRQ or timeout).

Do you have other drivers using DMA active? I would also try it on a different model of STM32, just in case...

Giovanni

Only PAL and UART drivers are active.