USART Printf example

  ******************** (C) COPYRIGHT 2014 STMicroelectronics *******************
  * @file    USART/USART_Printf/readme.txt 
  * @author  MCD Application Team
  * @version V1.4.0
  * @date    24-July-2014
  * @brief   Description of the USART Printf example.
  ******************************************************************************
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
   

Example Description

This example shows how to retarget the C library printf function to the USART. This implementation output the printf message on the Hyperterminal using USART1 for STM32F051R8T6 devices and USART2 for STM32F072VBT6 devices.

The USARTx is configured as follow:

• BaudRate = 115200 baud
• Word Length = 8 Bits
• One Stop Bit
• No parity
• Hardware flow control disabled (RTS and CTS signals)
• Receive and transmit enabled

Directory contents

• USART/Printf/stm32f0xx_conf.h Library Configuration file
• USART/Printf/stm32f0xx_it.h Interrupt handlers header file
• USART/Printf/stm32f0xx_it.c Interrupt handlers
• USART/Printf/main.c Main program
• PWR/PWR_STANDBY/main.h Header for main.c module
• USART/Printf/system_stm32f0xx.c STM32F0xx system source file

Note:

The "system_stm32f0xx.c" is generated by an automatic clock configuration tool and can be easily customized to meet user application requirements. To select different clock setup, use the "STM32F0xx_Clock_Configuration_VX.Y.Z.xls" provided with the AN4055 package available on ST Microcontrollers

Hardware and Software environment

• This example runs on STM32F0xx devices.

• This example has been tested with STMicroelectronics STM320518-EVAL and STM32072B-EVAL including respectively STM32F051R8T6 and STM32F072VBT6 devices and can be easily tailored to any other supported device and development board

• STM320518-EVAL Set-up
  • Connect a null-modem female/female RS232 cable between the DB9 connector CN7 and PC serial port.
• STM32072B-EVAL Set-up
  • Connect a null-modem female/female RS232 cable between the DB9 connector CN10 and PC serial port.

• Hyperterminal configuration:
  • Word Length = 8 Bits
  • One Stop Bit
  • No parity
  • BaudRate = 115200 baud
  • flow control: None

How to use it ?

In order to make the program work, you must do the following :

• Copy all source files from this example folder to the template folder under Project
• Open your preferred toolchain
• Select STM32F051 workspace
• If the used device is STM32F051R8T6 choose STM32F051 project
  • Add the following files to the project source list
    • Utilities\STM32_EVAL\STM320518_EVAL\stm320518_eval.c
• If the used device is STM32F072VBT6 choose STM32F072 project
  • Add the following files to the project source list
    • Utilities\STM32_EVAL\STM32072B_EVAL\stm32072b_eval.c
• Rebuild all files and load your image into target memory
• Run the example

Note:

Known Limitations This example retargets the C library printf() function to the Hyperterminal (C library I/O redirected). TrueSTUDIO Lite version does not support I/O redirection, and instead have do-nothing stubs compiled into the C runtime library. To use printf() with TrueSTUDIO Professional version, just include the TrueSTUDIO Minimal System calls file "syscalls.c" provided within the toolchain. It contains additional code to support printf() redirection.

© COPYRIGHT STMicroelectronics