CEC Receive messages to different destination example

  ******************** (C) COPYRIGHT 2014 STMicroelectronics *******************
  * @file    CEC/CEC_ListenMode/readme.txt 
  * @author  MCD Application Team
  * @version V1.4.0
  * @date    24-July-2014
  * @brief   Description of the CEC Receive messages to different destination 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:
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  *        http://www.st.com/software_license_agreement_liberty_v2
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  * 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
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Example Description

This example provides a basic communication, using interrupts, between two HDMI-CEC devices and an spy CEC device which receives messages addressed to different destination. The first and second CEC devices send a command to the other CEC device. The spy device can receive the data when Listen mode option is enabled. The data transfer is managed using CEC_IRQHandler in stm32f0xx_it.c file.

The example illustrates the use of the CEC communication between three devices (3 x STM320518/STM32072B-EVAL boards). A device can send a frame to the other device by pressing the Joystick button on the EVAL board and the spy device receives this message.

• Hardware Description To use this example, you need to load it on three STM320518/STM32072B-EVAL boards (let's call them Device_1, Device_2 and Device_3) then connect these boards through CEC lines (PB10 for STM320518-EVAL and PB08 for STM32072B-EVAL or HDMI connectors) and GND. In the firmware example, uncomment the dedicated line in the main.h file to use the CEC peripheral as Device_1 or as Device_2 or as Device_3.

• Software Description At each joystick buttons press:
  • The CEC device sends the specific command (Volume Up, Volume Down, OSD Name or CEC Version) to the specific device and the spy device receive the message command.

• The sender device can send a frame to the other device by pressing the JoyStick button on the EVAL board. Sending status is signaled by lightening and though as follow:
  • If Joystick RIGHT, LEFT, Up or Down is pressed and the data transmission is succeeded ==> Green Led(LD1) is ON.
  • If Joystick RIGHT, LEFT, Up or Down is pressed and the data transmission is failed ==> Red Led(LD3) is ON.

• The Receiver device receive data, Received data is signaled by LED lightening and though as follow:
  • OSD Name : Joystick RIGHT and data correctly received ==> LD1, LD2 ON and LD3,LD4 OFF,
  • CEC Version: Joystick LEFT and data correctly received ==> LD3, LD4 ON and LD1,LD2 OFF,
  • Volume Up : Joystick UP and data correctly received ==> LD1, LD2, LD3 and LD4 are ON,
  • Volume Down: Joystick DOWN and data correctly received ==> LD1, LD2, LD3 and LD4 are OFF.
  • If an error occurs during reception ==> Only LD3(Red LED) is ON.

Directory contents

• CEC/CEC_ListenMode/stm32f0xx_conf.h Library Configuration file
• CEC/CEC_ListenMode/stm32f0xx_it.c Interrupt handlers
• CEC/CEC_ListenMode/stm32f0xx_it.h Interrupt handlers header file
• CEC/CEC_ListenMode/main.c Main program
• CEC/CEC_ListenMode/main.h Header for main.c module
• CEC/CEC_ListenMode/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 the boards by using one of the two following alternatives:
    • A HDMI Cables between all boards HDMI-CEC connectors (CN3 or CN4) on STM320518-EVAL .
    • Use simple wires between all devices CEC Lines (PB.10), in this case don't forget to connect all boards grounds together.
• STM32072B-EVAL Set-up
  • Connect the boards by using one of the two following alternatives:
    • A HDMI Cables between all boards HDMI-CEC connectors (CN3 or CN5) on STM32072B-EVAL .
    • Use simple wires between all devices CEC Lines (PB.08), in this case don't forget to connect all boards grounds together.

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
    • Utilities\STM32_EVAL\STM320518_EVAL\stm320518_eval_lcd.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
    • Utilities\STM32_EVAL\STM32072B_EVAL\stm32072b_eval_lcd.c
• Rebuild all files and load your image into target memory
• Run the example

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