PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

skruglewicz — Wed, 15 Sep 2021 03:58:48 GMT

hello [mention:acaf6a9338de4eef8f6717d5561ed01d:e9ed411860ed4f2ba0265705b8793d05]

I am trying to follow your blog to implement your example. It seems like the Link you refer to at the beginning of the blog is broken?

"I follow the PSoC 6 documentation for Serial Communication Block configuration"

Can you direct me to the documentation you are referring to?

I'm using the PSOC 6 EVK: CY8Ckit-062S2-43012 . I've been able to follow some of your other blogs in your PSoC6 Series. I'm planning on a design that uses the Arduino Nano to connect to a UART on the PSoC 6.

Thanks

Steve K

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Wed, 23 Jun 2021 08:43:50 GMT

Hello Jan,

I found the problem source: the UART and the pins when configured by the Device Configurator actually reserve the pins.

This is why the second reservation, which is tried when cyhal_uart_init is called, fails.

If I don't configure the UART and the pins in the Configurator but with the CYHAL calls then the cyhal_uart_init

call works fine. Strange - there must be a way to use the configuration from the configurator and get straigt to the

uart object without calling cyhal_uart_init. Any idea ? I need to configure the MSB_first for this UART, as the external RS232 device

requires that.

Thanks much for your assistance so far !

Cheers

Stefan

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Tue, 22 Jun 2021 14:46:27 GMT

I did. P8_0 and P8_1 are available for UART 4. I debugged some, in the port_map I find P8_1 but not P8_0 that is strange.

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Tue, 22 Jun 2021 14:11:15 GMT

Hi Jan,

now I did just that. It does not recognize the pins now...

I get a CYHAL_UART_RSLT_ERR_INVALID_PIN error result from calling

/* Initialize the UART Block */

rslt = cyhal_uart_init(&uart_obj, CYBSP_UART1_TX, CYBSP_UART1_RX, CYPSP_UART1_CLK_HW, &uart_config);

if(rslt != CY_RSLT_SUCCESS)

{

handle_error();

}

The pins are named just like this in the Device Configurator. Seems like I am having trouble allocating the resources correctly.

Or there is some well hidden syntax when naming pins or clocks.

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Tue, 22 Jun 2021 10:35:11 GMT

Jan, I checked some things. The error I am getting does not appear unless I debug into the ISR. The Transmit actually runs through but then the Receive hangs.

Debugging into it indicates that a receive is actually in operation - this is probably the Receive in your task example.

so once I did the Transmit, how do I block the transmitting task and wait for the receive - using the xTaskToNotify flag ?

Thanks

Stefan

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Tue, 22 Jun 2021 09:54:00 GMT

Hi Jan,

I extern the variable outside of main where it is defined:

extern cy_stc_scb_uart_context_t uartContext;

It did not appear to be empty. What I see now is that I did not set the xTaskToNotify flag anywhere outside of your code example functions.

I have to check how you did that in your full sample project. Also, I disregarded the size of the rxBuffer until now. This should probably match

the number of bytes of the expected answer.

To cut short on complexity couldn't I just call

tx_status = Cy_SCB_UART_Transmit(scb_4_HW, txBuffer, sizeof(txBuffer), &uartContext);

if (tx_status != CY_SCB_UART_SUCCESS) {

handle_error();

}

/* Blocking wait for transmission completion */

while (0UL != (CY_SCB_UART_TRANSMIT_ACTIVE & Cy_SCB_UART_GetTransmitStatus(scb_4_HW, &uartContext)))

{

}

(void) Cy_SCB_UART_Receive(scb_4_HW, rxBuffer, sizeof(rxBuffer), &uartContext);

while (0UL != (CY_SCB_UART_RECEIVE_ACTIVE & Cy_SCB_UART_GetReceiveStatus(scb_4_HW, &uartContext))) {}

after the InitUART() from within any task that has the uartContext ? I thought it should then write and read fine. By the way, it seems that the ISR must be set up and initialized regardless.

And I did step into

Cy_SCB_UART_Interrupt(scb_4_HW, &uartContext)

but the debugger said it didn't find any symbols there. Guess I have to recompile some of the shared files or something

I will check that again.

Thank you very much Jan.

Cheers

Stefan

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Tue, 22 Jun 2021 05:26:20 GMT

Hello Jan,

thanks for your swift answer. I think it is not an issue with your task coordination logic.

I rather have difficulties addressing the UART which I configured using the Device Configurator

on SCB4. Seems like I do not register the interrupt correctly as the MCU throws a "cannot address memory" error when

Cy_SCB_UART_Interrupt(scb_4_HW, &uartContext); is called.

I have not found any working example that uses an UART configured with the Device Configurator. Any idea on how to

correctly address this resource ? Could be that scb_4_HW, which is generated by the Configurator, is not the correct

address to reach the configured UART ?

Thanks and best regards

Stefan

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

brandiware — Sat, 19 Jun 2021 14:36:48 GMT

Hello Jan,

I am trying to implement your logic in my code. However, it fails with the set / unset of the xTaskToNotify. It reaches the ISR with xTaskToNotify = NULL.

I have defined it as a global in my UART.c (see below). The init function I defined in the main and call it from there just as recommended.

In the debugger I get an error just when the code hits the ISR:

Error: Failed to read memory at 0xa5a5a5a6

The whole sequence of reading the UART should be kicked off by this code which is executed in a separate task:

tx_status = Cy_SCB_UART_Transmit(scb_4_HW, txBuffer, sizeof(txBuffer), &uartContext);

if (tx_status != CY_SCB_UART_SUCCESS) {

handle_error();

}

/* Blocking wait for transmission completion */

while (0UL != (CY_SCB_UART_TRANSMIT_ACTIVE & Cy_SCB_UART_GetTransmitStatus(scb_4_HW, &uartContext)))

{

}

Any idea what I could be missing here ? It seems like the xTaskToNotify gets lost in the context switch between the tasks.

Thanks for any help on this - we are working on a research project in ornithology and would like to kick off the research

beginning of july.

Cheers

Stefan

UART.c *************************************************

/* Allocate context for UART operation */

extern cy_stc_scb_uart_context_t uartContext;

static TaskHandle_t xTaskToNotify;

char rxBuffer[UART_BUFFER_SIZE];

void uart_task(void *pvParameters) {

/* To avoid compiler warnings */

(void)pvParameters;

uint32_t ulNotificationValue;

while (true) {

/* Start the receiving from UART. */

UART_receive();

/* Wait to be notified that the receive is complete. Note

the first parameter is pdTRUE, which has the effect of clearing

the task's notification value back to 0, making the notification

value act like a binary (rather than a counting) semaphore. */

ulNotificationValue = ulTaskNotifyTake(pdTRUE, portMAX_DELAY );

if( ulNotificationValue == 1 )

{

/* Blocking wait until buffer is full */

// in this example, it will never handle because the UART interrupt fires exactly when the buffer is full

while (0UL != (CY_SCB_UART_RECEIVE_ACTIVE & Cy_SCB_UART_GetReceiveStatus(scb_4_HW, &uartContext))) {}

/* Handle received data */

char tempBuffer[UART_BUFFER_SIZE];

sprintf(tempBuffer, rxBuffer);

}

// UART activate a receive with interrupt. Wait for ever for UART_BUFFER_SIZE bytes

void UART_receive() {

/* At this point xTaskToNotify should be NULL as no receive

is in progress. A mutex can be used to guard access to the

peripheral if necessary. */

configASSERT( xTaskToNotify == NULL );

/* Store the handle of the calling task. */

xTaskToNotify = xTaskGetCurrentTaskHandle();

/* Start receive operation (do not check status) */

(void) Cy_SCB_UART_Receive(scb_4_HW, rxBuffer, sizeof(rxBuffer), &uartContext);

}

// UART interrupt handler

void UART_Isr() {

Cy_SCB_UART_Interrupt(scb_4_HW, &uartContext);

BaseType_t xHigherPriorityTaskWoken = pdFALSE;

configASSERT( xTaskToNotify != NULL );

/* Notify the task that the receive is complete. */

vTaskNotifyGiveFromISR( xTaskToNotify, &xHigherPriorityTaskWoken );

/* There are no receive in progress, so no tasks to notify. */

xTaskToNotify = NULL;

/* If xHigherPriorityTaskWoken is now set to pdTRUE then a

context switch should be performed to ensure the interrupt

returns directly to the highest priority task. The macro used

for this purpose is dependent on the port in use and may be

called portEND_SWITCHING_ISR(). */

portYIELD_FROM_ISR( xHigherPriorityTaskWoken );

}

*****************************************************************************************************

main - initUART()

void initUART() {

cy_en_scb_uart_status_t init_status;

cy_en_sysint_status_t irq_init_status;

/* Configure UART to operate */

init_status = Cy_SCB_UART_Init(scb_4_HW, &scb_4_config, &uartContext);

if (init_status!=CY_SCB_UART_SUCCESS)

{

handle_error_main();

}

/* Populate configuration structure (code specific for CM4) */

cy_stc_sysint_t uartIntrConfig =

{

.intrSrc = UART_INTR_NUM,

.intrPriority = UART_INTR_PRIORITY,

};

/* Hook interrupt service routine and enable interrupt */

irq_init_status = Cy_SysInt_Init(&uartIntrConfig, &UART_Isr);

if (irq_init_status!=CY_SYSINT_SUCCESS)

{

handle_error();

}

NVIC_EnableIRQ(UART_INTR_NUM);

/* Enable UART to operate */

Cy_SCB_UART_Enable(scb_4_HW);

}

RE: PSoC 6 and ModusToolbox: UART receiver with FreeRTOS

balearicdynamics — Sat, 13 Mar 2021 23:21:44 GMT

Great piece of cooperation [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-0bbedc67-ca4d-4f75-bee5-1e2d5c2f9cb1/contentimage_5F00_3.png:16:16]

Enrico