/*
* Copyright (c) 2022 Libre Solar Technologies GmbH
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/zephyr.h>
#include <stdio.h>
#include <zephyr/device.h>
#include <zephyr/drivers/uart.h>
#include <sys/printk.h>
#include <drivers/uart.h>
#include <cJSON.h>
#include <string.h>
/* change this to any other UART peripheral if desired */
#define UART_DEVICE_NODE DT_CHOSEN(zephyr_shell_uart)
cJSON *root;
#define MSG_SIZE 300
/* queue to store up to 10 messages (aligned to 4-byte boundary) */
K_MSGQ_DEFINE(uart_msgq, MSG_SIZE, 10, 4);
static const struct device *uart_dev = DEVICE_DT_GET(DT_NODELABEL(uart0));
/* receive buffer used in UART ISR callback */
static char rx_buf[MSG_SIZE];
static int rx_buf_pos;
/*
* Read characters from UART until line end is detected. Afterwards push the
* data to the message queue.
*/
void serial_cb(const struct device *dev, void *user_data)
{
uint8_t c;
if (!uart_irq_update(uart_dev)) {
return;
}
while (uart_irq_rx_ready(uart_dev)) {
uart_fifo_read(uart_dev, &c, 1);
if ((c == '\n' || c == '\r') && rx_buf_pos > 0) {
/* terminate string */
rx_buf[rx_buf_pos] = '\0';
/* if queue is full, message is silently dropped */
k_msgq_put(&uart_msgq, &rx_buf, K_NO_WAIT);
/* reset the buffer (it was copied to the msgq) */
rx_buf_pos = 0;
} else if (rx_buf_pos < (sizeof(rx_buf) - 1)) {
rx_buf[rx_buf_pos++] = c;
}
/* else: characters beyond buffer size are dropped */
}
}
/*
* Print a null-terminated string character by character to the UART interface
*/
void uart_write(char *buf)
{
int msg_len = strlen(buf);
for (int i = 0; i < msg_len; i++) {
uart_poll_out(uart_dev, buf[i]);
}
}
int create_nrf5340rx_packet(cJSON* cmd) {
printk("NRF5340 Rx: Create data packet called\n");
cJSON *params;
cJSON *motor_pos;
cJSON *temp;
cJSON_AddItemToObject(cmd, "cmd", cJSON_CreateString("manualMotorControl"));
cJSON_AddItemToObject(cmd, "params", params = cJSON_CreateObject());
cJSON_AddItemToObject(params, "motor_pos", motor_pos = cJSON_CreateArray());
cJSON_AddItemToArray(motor_pos, temp = cJSON_CreateObject());
cJSON_AddNumberToObject(temp, "0", 0);
cJSON_AddItemToArray(motor_pos, temp = cJSON_CreateObject());
cJSON_AddNumberToObject(temp, "1", 90);
cJSON_AddItemToArray(motor_pos, temp = cJSON_CreateObject());
cJSON_AddNumberToObject(temp, "2", 180);
cJSON_AddItemToArray(motor_pos, temp = cJSON_CreateObject());
cJSON_AddNumberToObject(temp, "3", 270);
cJSON_AddNumberToObject(cmd, "timestamp", 1927);
char* tx_buf = cJSON_Print(root);
printk("Size of: %d \r\n", strlen(tx_buf));
cJSON_Delete(params);
cJSON_Delete(motor_pos);
cJSON_Delete(temp);
return 0;
}
int main(void)
{
char *tx_buf;
if (!device_is_ready(uart_dev)) {
printk("UART device not found!");
return;
}
/* configure interrupt and callback to receive data */
uart_irq_callback_user_data_set(uart_dev, serial_cb, NULL);
uart_irq_rx_enable(uart_dev);
//uart_write(tx_buf);
uart_write("Hello! I'm your echo bot.\r\n");
uart_write("Tell me something and press enter:\r\n");
root = cJSON_CreateObject();
create_nrf5340rx_packet(root);
return 0;
}
While running the mentioned code I am getting stack overflow error continuously. Can someone help me understand the reason behind that and what can be done to resolve such issue.
Error:
*** Booting Zephyr OS build v3.0.99-ncs1-1 *** system
Hello! I'm your echo bot.
Tell me something and press enter:
NRF5340 Rx: Create data packet called
[00:00:00.268,280] <err> os: ***** USAGE FAULT *****
[00:00:00.268,280] <err> os: Stack overflow (context area not valid)
[00:00:00.268,310] <err> os: r0/a1: 0x492d8255 r1/a2: 0xffbff3fd r2/a3: 0x0303188b
[00:00:00.268,310] <err> os: r3/a4: 0xdd2dfc5b r12/ip: 0x00018990 r14/lr: 0x81000000
[00:00:00.268,310] <err> os: xpsr: 0x00019a00
[00:00:00.268,341] <err> os: Faulting instruction address (r15/pc): 0x200100e0
[00:00:00.268,341] <err> os: >>> ZEPHYR FATAL ERROR 2: Stack overflow on CPU 0
[00:00:00.268,371] <err> os: Current thread: 0x20010930 (main)
