This module contains low level functions for USART interaction. More...

Files
file	stm32f103cb_usart.h
	Header file for stm32f103cb USART.

Macros
#define	USART_DEFAULT_BAUD USART_BAUD_9600
	The default baud rate used by setup function.

#define	USART_DEFAULT_STOP USART_STOP_ONE
	The default stop bits used by setup function.

#define	USART_DEFAULT_DATA USART_DATA_EIGHT
	The default data frame used by setup function.

#define	USART_DEFAULT_PARITY USART_PARITY_NONE
	The default parity used by setup function.

Typedefs
typedef void(*	v_fp_u8) (uint8_t)
	Function pointer typedef for void function with uint8_t parameter.

Enumerations

Functions
mcu_error	USART_setup (usart_periph peripheral)
	Initialize USART port. More...

mcu_error	USART_setBaud (usart_periph peripheral, usart_baud baud)
	Set the baud rate for the port. More...

v_fp_u8	USART_add_put (usart_periph peripheral)
	Return the address of the peripheral put function. More...

mcu_error	USART_put (usart_periph peripheral, uint8_t byte)
	Send a byte on the given peripheral. More...

uint8_t	USART_get (usart_periph peripheral)
	Get a byte on the given peripheral (blocking). More...

mcu_error	USART_setStop (usart_periph peripheral, usart_stop stopBits)
	Set the number of stop bits for the port. More...

mcu_error	USART_setParity (usart_periph peripheral, usart_parity parity)
	Set the parity for the port. More...

mcu_error	USART_setData (usart_periph peripheral, usart_data data)
	Set the data frame size for the port. More...

mcu_error	USART_setRxISR (usart_periph peripheral, void(*new_handler)(uint8_t received))
	Sets the target function called when recieve ISR is triggered. More...

mcu_error	USART_setTxISR (usart_periph peripheral, void(*new_handler)(void))
	Sets the target function called when transmit ISR is triggered. More...

mcu_error	USART_enableISR (usart_periph peripheral, usart_isr isr_type)
	Enables the specified ISR function. More...

mcu_error	USART_disableISR (usart_periph peripheral, usart_isr isr_type)
	Disables the specified ISR function. More...

Detailed Description

This module contains low level functions for USART interaction.

The USART peripherals are mapped to the following pins for the ports

USART_1:
- RX1 - PA10
- TX1 - PA9
USART_2:
- RX2 - PA3
- TX2 - PA2
USART_3:
- RX3 - PB11
- TX3 - PB10

Any USART data structure created needs to be initialized with USART_setup(), this function initializes the given usart peripheral with the following parameters

9600bps baud
1 Stop bit
8 bit data frame
No parity

Author: Stuart Ianna

Version: 0.1

Date: May 2018

Copyright: GNU GPLv3

Warning: None

Bug:: None

Todo:

Add function for interrupt priority configuration

Compilers

arm-none-eabi-gcc (15:4.9.3+svn231177-1) 4.9.3 20150529 (prerelease)

Minimum working example (blocking): //Change to include appropriate MCU target
#include <stm32f103cb_usart.h>
int main(void){
//Setup port 1
USART_setup(USART_1);
//ISR are enabled by default, they need to be disabled for blocking read
USART_disableISR(USART_1,USART_TX);
USART_disableISR(USART_1,USART_RX);
while(1){
//Echo characters back to the terminal
USART_put(USART_1,USART_get(USART_1));
}
return 0;
}

Minimum working example (interrupts): //Change to include appropriate MCU target
#include <stm32f103cb_usart.h>
void dataAvailable(uint8_t byte);
void dataSent(void);
int main(void){
//Setup port 1
USART_setup(USART_1);
//Retarget the ISRs to local functions
USART_setRxISR(USART_1,&dataAvailable);
USART_setTxISR(USART_1,&dataSent);
while(1){
//Nothing to do here
}
return 0;
}
//This is now called when a byte is available to be read
void dataAvailable(uint8_t byte){
//Echo characters back to terminal
USART_put(USART_1,byte);
}
//This is now called when a byte has finished being sent
void dataSent(void){
//Nothing to do here
}

Full example: example_usart.c

Enumeration Type Documentation

enum usart_baud

Baud rate options for the port.

These value are utilised with function USART_setBaud()

Enumerator
USART_BAUD_2400	2400bps baud rate
USART_BAUD_4800	4800bps buad rate
USART_BAUD_9600	9600bps baud rate
USART_BAUD_19200	19200bps baud rate
USART_BAUD_38400	38400bps baud rate
USART_BAUD_57600	57600bps baud rate
USART_BAUD_115200	115200bps baud rate

Definition at line 122 of file stm32f103cb_usart.h.

enum usart_data

Data frame lengths for the port.

These values are utilised with function USART_setData()

Enumerator
USART_DATA_EIGHT	Eight bit data frame for the port.
USART_DATA_NINE	Nine bit data frame for the port.

Definition at line 112 of file stm32f103cb_usart.h.

enum usart_isr

ISR values for the port.

These values are utilised with function USART_enableISR() and USART_disableISR()

Enumerator
USART_TX	Transmit ISR.
USART_RX	Recieve ISR.

Definition at line 137 of file stm32f103cb_usart.h.

enum usart_parity

Parity option available for the port.

These values are utilised with function USART_setParity()

Enumerator
USART_NONE	No parity for the port.
USART_ODD	Odd parity for the port.
USART_EVEN	Even parity for the port.

Definition at line 91 of file stm32f103cb_usart.h.

enum usart_periph

Peripheral ports available on the MCU.

These values are used with function USART_setup()

Enumerator
USART_1	First peripheral port.
USART_2	Second peripheral port.
USART_3	Third peripheral port.

Definition at line 79 of file stm32f103cb_usart.h.

enum usart_stop

Stop bit options available for the port.

These values are utilised with function USART_setStop()

Enumerator
USART_STOP_ONE	One stop bit for the port.
USART_STOP_TWO	Two stop bits for the port.

Definition at line 102 of file stm32f103cb_usart.h.

Function Documentation

v_fp_u8 USART_add_put ( usart_periph peripheral )

Return the address of the peripheral put function.

Parameters

peripheral The USART peripheral to get.

Returns: Error number as defined in mcu_error.

Definition at line 860 of file stm32f103cb_usart.c.

mcu_error USART_disableISR	(	usart_periph	peripheral,
		usart_isr	isr_type
	)

Disables the specified ISR function.

By default, ISRs are enabled. This can be used to disable them.

Parameters

peripheral	The USART peripheral to modify.
isr_type	The type of ISR to change, define by usart_isr

Returns: Error number as defined in mcu_error.

Definition at line 1047 of file stm32f103cb_usart.c.

mcu_error USART_enableISR	(	usart_periph	peripheral,
		usart_isr	isr_type
	)

Enables the specified ISR function.

Parameters

peripheral	The USART peripheral to modify.
isr_type	The type of ISR to change, define by usart_isr

Returns: Error number as defined in mcu_error.

Definition at line 1136 of file stm32f103cb_usart.c.

uint8_t USART_get ( usart_periph peripheral )

Get a byte on the given peripheral (blocking).

Parameters

peripheral The usart number to send on.

Returns: The byte recieved on the port.

Definition at line 891 of file stm32f103cb_usart.c.

mcu_error USART_put	(	usart_periph	peripheral,
		uint8_t	byte
	)

Send a byte on the given peripheral.

Parameters

peripheral	The usart number to send on.
byte	The byte to send.

Returns: Error number as defined in mcu_error.

Definition at line 826 of file stm32f103cb_usart.c.

mcu_error USART_setBaud	(	usart_periph	peripheral,
		usart_baud	baud
	)

Set the baud rate for the port.

Parameters

peripheral	The USART peripheral to modify.
baud	Baud rate defined by usart_baud to be used.

Returns: Error number as defined in mcu_error.

Definition at line 250 of file stm32f103cb_usart.c.

mcu_error USART_setData	(	usart_periph	peripheral,
		usart_data	data
	)

Set the data frame size for the port.

Parameters

peripheral	The USART peripheral to modify.
data	Data frame size as define in in usart_data.

Returns: Error number as defined in mcu_error.

Definition at line 565 of file stm32f103cb_usart.c.

mcu_error USART_setParity	(	usart_periph	peripheral,
		usart_parity	parity
	)

Set the parity for the port.

Parameters

peripheral	The USART peripheral to modify.
parity	Parity option defined in usart_parity.

Returns: Error number as defined in mcu_error.

Definition at line 687 of file stm32f103cb_usart.c.

mcu_error USART_setRxISR	(	usart_periph	peripheral,
		void(*)(uint8_t received)	new_handler
	)

Sets the target function called when recieve ISR is triggered.

The recieve ISR is called when a byte is ready to be read in the receive buffer.

By default, the ISR flag is cleared first then the function specified by this pointer is called.

If no function has been specified this pointed to NULL.

The function specified must be of this type.

Parameters

peripheral	The USART peripheral to modify.
new_handler	Address of the function for the ISR to point to.

Returns: Error number as defined in mcu_error.

Definition at line 983 of file stm32f103cb_usart.c.

mcu_error USART_setStop	(	usart_periph	peripheral,
		usart_stop	stopBits
	)

Set the number of stop bits for the port.

Parameters

peripheral	The USART peripheral to modify.
stopBits	Number of stop bits to use defined in usart_stop.

Returns: Error number as defined in mcu_error.

Definition at line 443 of file stm32f103cb_usart.c.

mcu_error USART_setTxISR	(	usart_periph	peripheral,
		void(*)(void)	new_handler
	)

Sets the target function called when transmit ISR is triggered.

The transmit ISR is called when a byte has finished being sent from the buffer.

By default, the ISR flag is cleared first then the function specified by this pointer is called.

If no function has been specified this pointed to NULL.

The function specified must be of this type.

Parameters

peripheral	The USART peripheral to modify.
new_handler	Address of the function for the ISR to point to.

Returns: Error number as defined in mcu_error.

Definition at line 1015 of file stm32f103cb_usart.c.

mcu_error USART_setup ( usart_periph peripheral )

Initialize USART port.

This must be called before any other feature is used.

This sets up the given USART peripheral to the default macro defined settings.

Parameters

peripheral The USART peripheral to modify.

Returns: Error number as defined in mcu_error.

Definition at line 79 of file stm32f103cb_usart.c.

Files

Macros

Typedefs

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

Function Documentation