/**
@page CEC CEC_DataExchange example
@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file CEC/CEC_DataExchange/readme.txt
* @author MCD Application Team
* @brief Description of the CEC Data Exchangeexample.
******************************************************************************
* @attention
*
* Copyright (c) 2016 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
@endverbatim
@par Example Description
How to configure and use the CEC peripheral to receive and transmit messages.
- Hardware Description
To use this example, two STM32091C-EVAL boards (called Device_1 and
Device_2) are loaded with the same software then connected through CEC lines
(PB10 or HDMI connectors) and GND.
/|\ In the firmware file main.h, uncomment the dedicated line to use
/_!_\ the CEC peripheral as STM32 device_1 or STM32 device_2.
@verbatim
*------------------------------------------------------------------------------*
| STM32091C_EVAL STM32091C_EVAL |
| Device Address :0x01 Device Address :0x03 |
| ____________________ ____________________ |
| | | | | |
| | | | | |
| | __________ | | __________ | |
| | | CEC |____|____CECLine______|____| CEC | | |
| | | Device_1 | | | | Device_2 | | |
| | |__________| | | |__________| | |
| | | | | |
| | O LD1 | | O LD1 | |
| | O LD2 Joystick | | O LD2 Joystick | |
| | O LD3 _ | | O LD3 _ | |
| | O LD4 |_| | | O LD4 |_| | |
| | | | | |
| | GND O--|-----------------|--O GND | |
| |____________________| |____________________| |
| |
| |
*------------------------------------------------------------------------------**
@endverbatim
- Software Description
The test unrolls as follows.
On TX side, four possible messages can be transmitted and are indicated as
below on the transmitting board:
- when Tamper push-button is pressed, LED1 toggles
- when Joystick Sel push-button is pressed, LED2 toggles
- when Joystick UP push-button is pressed, LED3 toggles
- when Joystick DOWN push-button is pressed, LED4 toggles
Accordingly, the following happens on the RX side in case of successful
reception:
- when Tamper push-button is pressed on TX side,
* all RX side LEDs are turned off
- when Joystick Sel push-button is pressed on TX side, on RX side
* LED1 and LED2 are turned on
* LED3 and LED4 are turned off
- when Joystick UP push-button is pressed on TX side,
* all RX side LEDs are turned on
- when Joystick DOWN push-button is pressed on TX side, on RX side
* LED1 and LED2 are turned off
* LED3 and LED4 are turned on
In case of unsuccessful reception, LED3 is turned on.
Practically, 2 EXTI lines (EXTI0_1 and EXTI4_15) are configured to
generate an interrupt on each falling or rising edge.
A specific message is then transmitted by the CEC IP
and a LED connected to a specific GPIO pin is toggled.
- EXTI0_1 is mapped to PA.00
- EXTI4_15 is mapped to PC.13, PE.04 and PE.05
Then, on TX side,
- when rising edge is detected on EXTI0_1, LED2 toggles
- when falling edge is detected on EXTI4_15 and EXTI line interrupt is detected
on PC.13, LED1 toggles
- when falling edge is detected on EXTI4_15 and EXTI line interrupt is detected
on PE.04, LED3 toggles
- when falling edge is detected on EXTI4_15 and EXTI line interrupt is detected
on PE.05, LED4 toggles
In this example, HCLK is configured at 48 MHz.
@par Directory contents
- CEC/CEC_DataExchange/Inc/stm32f0xx_hal_conf.h HAL configuration file
- CEC/CEC_DataExchange/Inc/stm32f0xx_it.h Interrupt handlers header file
- CEC/CEC_DataExchange/Inc/main.h Header for main.c module
- CEC/CEC_DataExchange/Src/stm32f0xx_it.c Interrupt handlers
- CEC/CEC_DataExchange/Src/system_stm32f0xx.c STM32F0xx system source file
- CEC/CEC_DataExchange/Src/main.c Main program
- CEC/CEC_DataExchange/Src/stm32f0xx_hal_msp.c IP hardware resources initialization
@par Hardware and Software environment
- This example runs on STM32091C Devices.
- This example has been tested with STM32091C-EVAL board and can be
easily tailored to any other supported device and development board.
@par How to use it ?
In order to make the program work, you must do the following :
- Open your preferred toolchain
- in main.h, uncomment DEVICE_1 for first board, uncomment DEVICE_2 for second board
- Rebuild all files and load your image into target memory
- With a wire, connect HDMI_CEC_LINE_GPIO_PORT-HDMI_CEC_LINE_PIN between the 2 boards
- Connect the ground of the 2 boards
- Run the example
*/
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