265 lines
9.7 KiB
C
265 lines
9.7 KiB
C
/* CAN Network Slave Example
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This example code is in the Public Domain (or CC0 licensed, at your option.)
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Unless required by applicable law or agreed to in writing, this
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software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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CONDITIONS OF ANY KIND, either express or implied.
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*/
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/*
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* The following example demonstrates a slave node in a CAN network. The slave
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* node is responsible for sending data messages to the master. The example will
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* execute multiple iterations, with each iteration the slave node will do the
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* following:
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* 1) Start the CAN driver
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* 2) Listen for ping messages from master, and send ping response
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* 3) Listen for start command from master
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* 4) Send data messages to master and listen for stop command
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* 5) Send stop response to master
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* 6) Stop the CAN driver
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "freertos/queue.h"
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#include "freertos/semphr.h"
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#include "esp_err.h"
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#include "esp_log.h"
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#include "driver/can.h"
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/* --------------------- Definitions and static variables ------------------ */
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//Example Configuration
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#define DATA_PERIOD_MS 50
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#define NO_OF_ITERS 3
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#define ITER_DELAY_MS 1000
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#define RX_TASK_PRIO 8 //Receiving task priority
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#define TX_TASK_PRIO 9 //Sending task priority
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#define CTRL_TSK_PRIO 10 //Control task priority
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#define TX_GPIO_NUM 21
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#define RX_GPIO_NUM 22
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#define EXAMPLE_TAG "CAN Slave"
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#define ID_MASTER_STOP_CMD 0x0A0
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#define ID_MASTER_START_CMD 0x0A1
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#define ID_MASTER_PING 0x0A2
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#define ID_SLAVE_STOP_RESP 0x0B0
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#define ID_SLAVE_DATA 0x0B1
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#define ID_SLAVE_PING_RESP 0x0B2
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typedef enum {
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TX_SEND_PING_RESP,
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TX_SEND_DATA,
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TX_SEND_STOP_RESP,
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TX_TASK_EXIT,
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} tx_task_action_t;
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typedef enum {
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RX_RECEIVE_PING,
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RX_RECEIVE_START_CMD,
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RX_RECEIVE_STOP_CMD,
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RX_TASK_EXIT,
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} rx_task_action_t;
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static const can_general_config_t g_config = CAN_GENERAL_CONFIG_DEFAULT(TX_GPIO_NUM, RX_GPIO_NUM, CAN_MODE_NORMAL);
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static const can_timing_config_t t_config = CAN_TIMING_CONFIG_25KBITS();
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static const can_filter_config_t f_config = CAN_FILTER_CONFIG_ACCEPT_ALL();
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static const can_message_t ping_resp = {.identifier = ID_SLAVE_PING_RESP, .data_length_code = 0,
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.flags = CAN_MSG_FLAG_NONE, .data = {0, 0 , 0 , 0 ,0 ,0 ,0 ,0}};
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static const can_message_t stop_resp = {.identifier = ID_SLAVE_STOP_RESP, .data_length_code = 0,
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.flags = CAN_MSG_FLAG_NONE, .data = {0, 0 , 0 , 0 ,0 ,0 ,0 ,0}};
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//Data bytes of data message will be initialized in the transmit task
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static can_message_t data_message = {.identifier = ID_SLAVE_DATA, .data_length_code = 4,
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.flags = CAN_MSG_FLAG_NONE, .data = {0, 0 , 0 , 0 ,0 ,0 ,0 ,0}};
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static QueueHandle_t tx_task_queue;
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static QueueHandle_t rx_task_queue;
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static SemaphoreHandle_t ctrl_task_sem;
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static SemaphoreHandle_t stop_data_sem;
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static SemaphoreHandle_t done_sem;
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/* --------------------------- Tasks and Functions -------------------------- */
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static void can_receive_task(void *arg)
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{
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while (1) {
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rx_task_action_t action;
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xQueueReceive(rx_task_queue, &action, portMAX_DELAY);
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if (action == RX_RECEIVE_PING) {
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//Listen for pings from master
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can_message_t rx_msg;
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while (1) {
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can_receive(&rx_msg, portMAX_DELAY);
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if (rx_msg.identifier == ID_MASTER_PING) {
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xSemaphoreGive(ctrl_task_sem);
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break;
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}
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}
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} else if (action == RX_RECEIVE_START_CMD) {
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//Listen for start command from master
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can_message_t rx_msg;
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while (1) {
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can_receive(&rx_msg, portMAX_DELAY);
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if (rx_msg.identifier == ID_MASTER_START_CMD) {
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xSemaphoreGive(ctrl_task_sem);
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break;
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}
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}
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} else if (action == RX_RECEIVE_STOP_CMD) {
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//Listen for stop command from master
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can_message_t rx_msg;
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while (1) {
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can_receive(&rx_msg, portMAX_DELAY);
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if (rx_msg.identifier == ID_MASTER_STOP_CMD) {
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xSemaphoreGive(stop_data_sem);
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xSemaphoreGive(ctrl_task_sem);
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break;
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}
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}
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} else if (action == RX_TASK_EXIT) {
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break;
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}
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}
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vTaskDelete(NULL);
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}
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static void can_transmit_task(void *arg)
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{
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while (1) {
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tx_task_action_t action;
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xQueueReceive(tx_task_queue, &action, portMAX_DELAY);
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if (action == TX_SEND_PING_RESP) {
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//Transmit ping response to master
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can_transmit(&ping_resp, portMAX_DELAY);
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ESP_LOGI(EXAMPLE_TAG, "Transmitted ping response");
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xSemaphoreGive(ctrl_task_sem);
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} else if (action == TX_SEND_DATA) {
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//Transmit data messages until stop command is received
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ESP_LOGI(EXAMPLE_TAG, "Start transmitting data");
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while (1) {
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//FreeRTOS tick count used to simulate sensor data
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uint32_t sensor_data = xTaskGetTickCount();
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for (int i = 0; i < 4; i++) {
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data_message.data[i] = (sensor_data >> (i * 8)) & 0xFF;
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}
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can_transmit(&data_message, portMAX_DELAY);
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ESP_LOGI(EXAMPLE_TAG, "Transmitted data value %d", sensor_data);
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vTaskDelay(pdMS_TO_TICKS(DATA_PERIOD_MS));
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if (xSemaphoreTake(stop_data_sem, 0) == pdTRUE) {
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break;
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}
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}
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} else if (action == TX_SEND_STOP_RESP) {
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//Transmit stop response to master
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can_transmit(&stop_resp, portMAX_DELAY);
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ESP_LOGI(EXAMPLE_TAG, "Transmitted stop response");
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xSemaphoreGive(ctrl_task_sem);
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} else if (action == TX_TASK_EXIT) {
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break;
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}
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}
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vTaskDelete(NULL);
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}
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static void can_control_task(void *arg)
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{
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xSemaphoreTake(ctrl_task_sem, portMAX_DELAY);
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tx_task_action_t tx_action;
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rx_task_action_t rx_action;
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for (int iter = 0; iter < NO_OF_ITERS; iter++) {
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ESP_ERROR_CHECK(can_start());
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ESP_LOGI(EXAMPLE_TAG, "Driver started");
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//Listen of pings from master
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rx_action = RX_RECEIVE_PING;
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xQueueSend(rx_task_queue, &rx_action, portMAX_DELAY);
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xSemaphoreTake(ctrl_task_sem, portMAX_DELAY);
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//Send ping response
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tx_action = TX_SEND_PING_RESP;
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xQueueSend(tx_task_queue, &tx_action, portMAX_DELAY);
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xSemaphoreTake(ctrl_task_sem, portMAX_DELAY);
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//Listen for start command
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rx_action = RX_RECEIVE_START_CMD;
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xQueueSend(rx_task_queue, &rx_action, portMAX_DELAY);
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xSemaphoreTake(ctrl_task_sem, portMAX_DELAY);
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//Start sending data messages and listen for stop command
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tx_action = TX_SEND_DATA;
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rx_action = RX_RECEIVE_STOP_CMD;
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xQueueSend(tx_task_queue, &tx_action, portMAX_DELAY);
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xQueueSend(rx_task_queue, &rx_action, portMAX_DELAY);
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xSemaphoreTake(ctrl_task_sem, portMAX_DELAY);
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//Send stop response
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tx_action = TX_SEND_STOP_RESP;
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xQueueSend(tx_task_queue, &tx_action, portMAX_DELAY);
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xSemaphoreTake(ctrl_task_sem, portMAX_DELAY);
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//Wait for bus to become free
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can_status_info_t status_info;
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can_get_status_info(&status_info);
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while (status_info.msgs_to_tx > 0) {
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vTaskDelay(pdMS_TO_TICKS(100));
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can_get_status_info(&status_info);
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}
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ESP_ERROR_CHECK(can_stop());
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ESP_LOGI(EXAMPLE_TAG, "Driver stopped");
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vTaskDelay(pdMS_TO_TICKS(ITER_DELAY_MS));
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}
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//Stop TX and RX tasks
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tx_action = TX_TASK_EXIT;
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rx_action = RX_TASK_EXIT;
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xQueueSend(tx_task_queue, &tx_action, portMAX_DELAY);
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xQueueSend(rx_task_queue, &rx_action, portMAX_DELAY);
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//Delete Control task
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xSemaphoreGive(done_sem);
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vTaskDelete(NULL);
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}
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void app_main()
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{
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//Add short delay to allow master it to initialize first
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for (int i = 3; i > 0; i--) {
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printf("Slave starting in %d\n", i);
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vTaskDelay(pdMS_TO_TICKS(1000));
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}
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//Create semaphores and tasks
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tx_task_queue = xQueueCreate(1, sizeof(tx_task_action_t));
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rx_task_queue = xQueueCreate(1, sizeof(rx_task_action_t));
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ctrl_task_sem = xSemaphoreCreateBinary();
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stop_data_sem = xSemaphoreCreateBinary();;
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done_sem = xSemaphoreCreateBinary();;
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xTaskCreatePinnedToCore(can_receive_task, "CAN_rx", 4096, NULL, RX_TASK_PRIO, NULL, tskNO_AFFINITY);
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xTaskCreatePinnedToCore(can_transmit_task, "CAN_tx", 4096, NULL, TX_TASK_PRIO, NULL, tskNO_AFFINITY);
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xTaskCreatePinnedToCore(can_control_task, "CAN_ctrl", 4096, NULL, CTRL_TSK_PRIO, NULL, tskNO_AFFINITY);
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//Install CAN driver, trigger tasks to start
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ESP_ERROR_CHECK(can_driver_install(&g_config, &t_config, &f_config));
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ESP_LOGI(EXAMPLE_TAG, "Driver installed");
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xSemaphoreGive(ctrl_task_sem); //Start Control task
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xSemaphoreTake(done_sem, portMAX_DELAY); //Wait for tasks to complete
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//Uninstall CAN driver
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ESP_ERROR_CHECK(can_driver_uninstall());
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ESP_LOGI(EXAMPLE_TAG, "Driver uninstalled");
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//Cleanup
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vSemaphoreDelete(ctrl_task_sem);
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vSemaphoreDelete(stop_data_sem);
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vSemaphoreDelete(done_sem);
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vQueueDelete(tx_task_queue);
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vQueueDelete(rx_task_queue);
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}
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