lesson-5.rst

Zephyr Behaviour Tree - Tutorial - Lesson 5

Using ZBUS

1 - In this instruction will be necessary to use some board. The content was developed using the ST Nucleo F767-ZI.

In this case, to build you need to change your command to:

west build -p -b nucleo_f767zi samples/subsys/zephyrbt/tutorial

west flash [-r openocd]

2- This example consist in turn a led On/Off depending on the fridge door state. To copy the files, navigate to samples/subsys/zephyrbt/tutorial folder and execute the following command.

cp -r lessons/lesson-5/resources/* .

In the boards folder a new configuration was created to enable PWM leds. In the zbus_peripherals.h file it is defined the structs to handle the peripherals states. In this case, the ZBUS_PERIPHERAL_WRITE abstracts the peripherals and update the state in case of changes. The zbus_peripherals.c is given to fullfil the purpose of the sample. It defines a channel and the peripherals thread. With those files it is possible to update the fridge.c file.

/* Add the new two include files */
#include <zephyr/zbus/zbus.h>
#include "zbus_peripherals.h"

/* Declare the channel to allow send data */
ZBUS_CHAN_DECLARE(peripherals_channel);

/* Use the channel */
ZBUS_PERIPHERAL_WRITE(.led_green.state = LEDS_STATES_ON);

/* Multiple peripherals can be updated at same time */
ZBUS_PERIPHERAL_WRITE(
     .led_green.state = LEDS_STATES_ON,
     .led_red.state = LEDS_STATES_OFF
);