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/**
@page CEC CEC_MultiAddress example
@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file CEC/CEC_MultiAddress/readme.txt
* @author MCD Application Team
* @brief Description of the CEC Multiple Address communication example.
******************************************************************************
* @attention
*
* <h2><center>© Copyright (c) 2016 STMicroelectronics.
* All rights reserved.</center></h2>
*
* This software component is licensed by ST under BSD 3-Clause license,
* the "License"; You may not use this file except in compliance with the
* License. You may obtain a copy of the License at:
* opensource.org/licenses/BSD-3-Clause
*
******************************************************************************
@endverbatim
@par Example Description
How to configure and use the CEC peripheral to receive and transmit messages
in the case where one device supports two distinct logical addresses at the
same time.
- Hardware Description
To use this example, two STM32072B-EVAL RevB boards (called Device_1 and
Device_2) are loaded with the same software then connected through CEC lines
(PB8 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
*------------------------------------------------------------------------------*
| STM32072B-EVAL RevB STM32072B-EVAL RevB |
| Device Address :0x01 Device Address :0x03 |
| Device Address :0x05) |
| ____________________ ____________________ |
| | | | | |
| | | | | |
| | __________ | | __________ | |
| | | 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 Device_1 TX side, three possible messages can be transmitted and are
indicated as below on the transmitting board:
- when Tamper push-button is pressed, a ping message (no payload) is addressed
to Device_2 first logical address; LED1 toggles
- when Joystick DOWN push-button is pressed, a ping message (no payload) is addressed
to Device_2 second logical address; LED4 toggles
- when Joystick Sel push-button is pressed, a broadcast message (with empty
payload) is sent by Device_1; LED2 toggles
When Joystick UP push-button is pressed, LED3 toggles (no message sent)
Accordingly, the following happens on Device_2 RX side in case of successful
reception:
- when Tamper push-button is pressed on TX side,
* LED1 is turned on
* LED3 and LED4 are turned off
- when Joystick DOWN push-button is pressed on TX side,
* LED4 is turned on
* LED1 and LED3 are turned off
- when Joystick Sel push-button is pressed on TX side, all LEDs are turned off
Conversely, on Device_2 TX side, only ping messages addressed to the
single Device_1 logical address or broadcast messages are sent:
- when Tamper push-button is pressed, a ping message (no payload) is addressed
to Device_2; LED1 toggles
- when Joystick DOWN push-button is pressed, a ping message (no payload) is addressed
to Device_2; LED4 toggles
- when Joystick Sel push-button is pressed, a broadcast message (with empty
payload) is sent; LED2 toggles
Accordingly, the following happens on Device_1 RX side in case of successful
transmission:
- when Tamper or Joystick DOWN push-button are pressed on TX side,
* LED1 and LED4 are turned on
* LED 3 is turned off
- when Joystick Sel push-button is pressed on TX side, all LEDs are turned off
For Device_1 and _2, in case of transmission or reception error,
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, PF.09 and PF.10
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 PF.09, LED3 toggles
- when falling edge is detected on EXTI4_15 and EXTI line interrupt is detected
on PF.10, LED4 toggles
In this example, HCLK is configured at 48 MHz.
@par Directory contents
- CEC/CEC_MultiAddress/Inc/stm32f0xx_hal_conf.h HAL configuration file
- CEC/CEC_MultiAddress/Inc/stm32f0xx_it.h Interrupt handlers header file
- CEC/CEC_MultiAddress/Inc/main.h Header for main.c module
- CEC/CEC_MultiAddress/Src/stm32f0xx_it.c Interrupt handlers
- CEC/CEC_MultiAddress/Src/system_stm32f0xx.c STM32F0xx system source file
- CEC/CEC_MultiAddress/Src/main.c Main program
- CEC/CEC_MultiAddress/Src/stm32f0xx_hal_msp.c IP hardware resources initialization
@par Hardware and Software environment
- This example runs on STM32F072VB devices.
- This example has been tested with STM32072B-EVAL RevB 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
* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
*/