topic Re: UART example on FRDM-KL05Z board for KDS in Kinetis Microcontrollers

UART example on FRDM-KL05Z board for KDS

ionchifu — Fri, 09 Oct 2015 14:49:31 GMT

Hello, my name is Alex and I am new in this community. I recently started a project using the FRDM-KL05Z board and I am interested in some examples on how to configure the UART protocol without Processor Expert. So far I found some init and read/write methods but they don't seem to work properly.

Below you can find the code for this methods :

void uart_init (UART_MemMapPtr uartch, int sysclk, int baud)

{

uint8 temp;

/* Enable the clock to the selected UART */

if(uartch == UART0_BASE_PTR)

SIM_SCGC4 |= SIM_SCGC4_UART0_MASK;

else

if (uartch == UART1_BASE_PTR)

SIM_SCGC4 |= SIM_SCGC4_UART1_MASK;

else

if (uartch == UART2_BASE_PTR)

SIM_SCGC4 |= SIM_SCGC4_UART2_MASK;

else

if(uartch == UART3_BASE_PTR)

SIM_SCGC4 |= SIM_SCGC4_UART3_MASK;

else

if(uartch == UART4_BASE_PTR)

SIM_SCGC1 |= SIM_SCGC1_UART4_MASK;

else

SIM_SCGC1 |= SIM_SCGC1_UART5_MASK;

/* Make sure that the transmitter and receiver are disabled while we

* change settings.

UART_C2_REG(uartch) &= ~(UART_C2_TE_MASK

| UART_C2_RE_MASK );

/* Configure the UART for 8-bit mode, no parity */

UART_C1_REG(uartch) = 0; /* We need all default settings, so entire register is cleared */

/* Calculate baud settings */

sbr = (uint16)((sysclk*1000)/(baud * 16));

/* Save off the current value of the UARTx_BDH except for the SBR field */

temp = UART_BDH_REG(uartch) & ~(UART_BDH_SBR(0x1F));

UART_BDH_REG(uartch) = temp | UART_BDH_SBR(((sbr & 0x1F00) >> 8));

UART_BDL_REG(uartch) = (uint8)(sbr & UART_BDL_SBR_MASK);

/* Determine if a fractional divider is needed to get closer to the baud rate */

brfa = (((sysclk*32000)/(baud * 16)) - (sbr * 32));

/* Save off the current value of the UARTx_C4 register except for the BRFA field */

temp = UART_C4_REG(uartch) & ~(UART_C4_BRFA(0x1F));

UART_C4_REG(uartch) = temp | UART_C4_BRFA(brfa);

/* Enable receiver and transmitter */

UART_C2_REG(uartch) |= (UART_C2_TE_MASK

| UART_C2_RE_MASK );

}

/********************************************************************/

* Wait for a character to be received on the specified UART

* Parameters:

* channel UART channel to read from

* Return Values:

* the received character

char uart_getchar (UART_MemMapPtr channel)

{

/* Wait until character has been received */

while (!(UART_S1_REG(channel) & UART_S1_RDRF_MASK));

/* Return the 8-bit data from the receiver */

return UART_D_REG(channel);

}

/********************************************************************/

* Wait for space in the UART Tx FIFO and then send a character

* Parameters:

* channel UART channel to send to

* ch character to send

void uart_putchar (UART_MemMapPtr channel, char ch)

{

/* Wait until space is available in the FIFO */

while(!(UART_S1_REG(channel) & UART_S1_TDRE_MASK));

/* Send the character */

UART_D_REG(channel) = (uint8)ch;

}

/********************************************************************/

* Check to see if a character has been received

* Parameters:

* channel UART channel to check for a character

* Return values:

* 0 No character received

* 1 Character has been received

int uart_getchar_present (UART_MemMapPtr channel)

{

return (UART_S1_REG(channel) & UART_S1_RDRF_MASK);

}

I was just wondering if anyone used those routines or something similar or has an example on how to communicate with a terminal using the UART protocol on the FRDM-KL05Z board.

This is my first time using a freescale microcontroller so I don't fully understand all it's aspects so any information will be greatly appreciated.

Re: UART example on FRDM-KL05Z board for KDS

mjbcswitzerland — Sat, 10 Oct 2015 16:58:30 GMT

Your code is for a K-type device and is not compatible with the KL parts.

Regards

Mark

Kinetis: http://www.utasker.com/kinetis.html

KL05: http://www.utasker.com/kinetis/FRDM-KL05Z.html

UARTs: http://www.utasker.com/docs/uTasker/uTaskerUART.PDF

For the complete "out-of-the-box" Kinetis experience and faster time to market

:smileyinfo: Out-of-the-box support for 46 Kinetis boards and 10 IDEs (460 combinations from a single code source with no porting required)

Re: UART example on FRDM-KL05Z board for KDS

Alice_Yang — Mon, 12 Oct 2015 02:44:22 GMT

Hello ION,

- There is FRDM-KL05 sample code package , it have UART driver, after you download it , you can find here :

KL05-SC\KL05-SC\klxx-sc-baremetal\src\drivers\uart

you can download it here :

Freedom Development Platform for Kinetis MCUs|Freescale

- And why you do not use Processor Expert , it is a good tool help you develop the project , there also is sample code about how to use it .

For example : add the component "Serial_LDD" , right click it , you can find "help on component" , then in the "Typical Usage" you can find

how to configure it and the demo code :

Hope it helps

Have a great day,

Alice

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Re: UART example on FRDM-KL05Z board for KDS

ionchifu — Tue, 13 Oct 2015 06:23:25 GMT

Thanks for the reply Alice, i am not using Processor Expert because i want to do everything from the start as a baremetal project and because further in the project i want to optimize the power consumption so i want to write as little code as possible. Below there is a code i edited for my board but it won't work.. the data register just won't save the value that a send to the terminal. Did anyone else encounter this problem ?

#include "MKL05Z4.h"

#include "uart.h"

void uart0_init (UART0_MemMapPtr uartch, int sysclk, int baud)

{

/* Enable the clock to the selected PORT */

SIM_SCGC5 |= SIM_SCGC5_PORTB_MASK;

/* Set the pins multiplexer to UART RX/TX mode */

PORTB->PCR[1] = ( PORT_PCR_ISF_MASK | PORT_PCR_MUX(3) );

PORTB->PCR[2] = ( PORT_PCR_ISF_MASK | PORT_PCR_MUX(3) );

/* Enable the clock to the selected UART */

SIM->SOPT2 = SIM_SOPT2_UART0SRC(1);

SIM->SCGC4 |= SIM_SCGC4_UART0_MASK;

/* Make sure that the transmitter and receiver are disabled while we

* change settings.

UART0_C2 = 0x00U;

/* Configure the UART for a 9600 baud rate */

UART0_BDL = UART0_BDL_SBR(0xC8);

UART0_BDH = UART0_BDH_SBR(0x00);

UART0_MA1 = UART0_MA1_MA(0x00);

UART0_MA2 = UART0_MA2_MA(0x00);

UART0_C4 = UART0_C4_OSR(0x18);

UART0_C1 = 0x00U;

UART0_S1 = 0xC0U;

UART0_S2 = (UART0_S2_LBKDIF_MASK | UART0_S2_RXEDGIF_MASK);

(void) UART0_D;

UART0_C5 = 0x00U;

UART0_C3 = 0x00U;

/* Enable transmitter and receiver */

UART0_C2 |= (UART0_C2_TE_MASK | UART0_C2_RE_MASK);

}

/********************************************************************/

* Wait for a character to be received on the specified uart

* Parameters:

* channel uart channel to read from

* Return Values:

* the received character

char uart0_getchar (UART0_MemMapPtr channel)

{

/* Wait until character has been received */

while (!(UART0_S1_REG(channel) & UART0_S1_RDRF_MASK));

/* Return the 8-bit data from the receiver */

return UART0_D_REG(channel);

}

/********************************************************************/

* Wait for space in the uart Tx FIFO and then send a character

* Parameters:

* channel uart channel to send to

* ch character to send

void uart0_putchar (UART0_MemMapPtr channel, char *ch)

{

int i = 0;

while (*(ch + i) != '\0')

{

/* Wait until space is available in the FIFO */

while(!(UART0_S1_REG(channel) & UART0_S1_TDRE_MASK));

/* Send the character */

UART0->D = *(ch + i);

i++;

}

/********************************************************************/

* Check to see if a character has been received

* Parameters:

* channel uart channel to check for a character

* Return values:

* 0 No character received

* 1 Character has been received

int uart0_getchar_present (UART0_MemMapPtr channel)

{

return (UART0_S1_REG(channel) & UART0_S1_RDRF_MASK);

}

int main()

{

int i = 0;

char text[128] = "Hello world";

uart0_init(UART0, 48000, 9600);

while (1)

{

uart0_putchar(UART0, text );

}

////////////////////////////////////////////////////////////////////////////////

// EOF

////////////////////////////////////////////////////////////////////////////////

Re: UART example on FRDM-KL05Z board for KDS

mjbcswitzerland — Tue, 13 Oct 2015 13:58:54 GMT

The amount of code will have no influence on the power consumption.

See the following for a report on using UARTs in low power mode: Using Kinetis Low Power Stop Modes with unrestricted UART operation - a report

In fact, using a blocking method as you have used to write a string will have higher current consumption than using an interrupt/DMA driven one that allows the processor to stop the core while waiting for each byte to be transmitted.

Regards

Mark

Kinetis: http://www.utasker.com/kinetis.html

KL05: http://www.utasker.com/kinetis/FRDM-KL05Z.html

UARTs: http://www.utasker.com/docs/uTasker/uTaskerUART.PDF

For the complete "out-of-the-box" Kinetis experience and faster time to market

:smileyinfo: Out-of-the-box boot loader support for 46 Kinetis boards, 8 modes and 10 IDEs (over 15'000 combinations from a single code source with no porting required)

Re: UART example on FRDM-KL05Z board for KDS

Alice_Yang — Wed, 14 Oct 2015 04:02:48 GMT

Hello ION,

After i checked your code , i found one error here :

PORTB->PCR[1] = ( PORT_PCR_ISF_MASK | PORT_PCR_MUX(3) );

PORTB->PCR[2] = ( PORT_PCR_ISF_MASK | PORT_PCR_MUX(3) );

Please change it to :

PORTB->PCR[1] = ( PORT_PCR_ISF_MASK | PORT_PCR_MUX(2) );

PORTB->PCR[2] = ( PORT_PCR_ISF_MASK | PORT_PCR_MUX(2) );

For from the SCH we can see the FRDM-KL05 use the PTB2 as UART0_RX, use the PTB1 as UART0_TX.

Hope it helps

Have a great day,
Alice