cJSON error

RE: cJSON error

Thabet — Thu, 03 Mar 2022 18:29:58 GMT

I know this topic is old, but I have this problem and apparently this solution is no longer working, could you give another solution to work with numbers through the cJSON lib?

I have no problem using cJSON_AddItemToObject, I can send strings, but when I try to send any number I find the problem. I have also configured:

CONFIG_MAIN_STACK_SIZE=16384

CONFIG_HEAP_MEM_POOL_SIZE=16384

I inserted all the recommendations both in prj.conf, and in relation to libraries and cJSON_Init at the beginning of main, but I keep getting a Hard Fault, could you check if this solution still works for you? I'm using NCS 1.8.0!

RE: cJSON error

Carl Richard — Wed, 25 Nov 2020 10:17:00 GMT

Hi, Ephraim!

Good that you are progressing. Some comments:
- One line 22 of your code you are adding a number object to the array in the wrong way, which in itself may cause trouble.
- On line 27 you are creating an entirely new array. If you want to add the existing array use cJSON_AddItemToObject(root, "payload", payload).

Anyway, I got this working with the code below:

/*
 * Copyright (c) 2012-2014 Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr.h>
#include <sys/printk.h>
#include <cJSON.h>
#include <cJSON_os.h>

void createJsonFromParams(void)
{
	char *command = "periodic"; //  "holter"  "holtersm" "spot"   "time"
	char *type = "8";

	cJSON *root = cJSON_CreateObject();
	cJSON_AddStringToObject(root, "command", command);
	cJSON_AddStringToObject(root, "type", type);
   //cJSON_AddNumberToObject(root, "number", 33);

   cJSON * payload = cJSON_AddArrayToObject(root, "payload");

   cJSON_AddItemToArray(payload, cJSON_CreateNumber(33));

   printk("%s",cJSON_Print(root));
   cJSON_Delete(root);
}

void main(void)
{
   cJSON_Init();

	while (1) {
      createJsonFromParams();
		k_sleep(K_MSEC(5000));
	}
}

And the following prj.conf:

CONFIG_SERIAL=y
CONFIG_DK_LIBRARY=y
CONFIG_CJSON_LIB=y
CONFIG_NEWLIB_LIBC=y
CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y
CONFIG_ASSERT=y

CONFIG_HEAP_MEM_POOL_SIZE=8192
CONFIG_MAIN_STACK_SIZE=8192

Note that cJSON_Init is called at the start of main. This enables use and printing of the number object.

Best regads,
Carl Richard

RE: cJSON error

ephraim — Wed, 25 Nov 2020 07:23:54 GMT

This problem is over .

I added the following lines to prj.conf .

CONFIG_CJSON_LIB=y
CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y

However a new problem that I encounter,

I do able to produce a JSON string .

In the string I insert a array , I can't fill the array with data like [12,13,45,234,34,5,99]

The array is always empty [] ,

I use the following code.

cJSON * createJsonFromParams(void)
{

  char * command = "periodic" ;//  "holter"  "holtersm" "spot"   "time"
  char * type  = "8";
//  char * start_time  = "1845";
//  char * duration  = "104";
//  char * rest  = "29";
//  char * stop_time  = "27000";
//  char * payload =  "Etrog2020";
//  int * payload = 123456; //"Etrog2020"; //  {0x06,0x05,0x04,0x03,0x02,0x01}; //
//  cJSON *number_item = cJSON_CreateNumber(1942);

  cJSON *root = cJSON_CreateObject();
  cJSON_AddStringToObject(root, "command", command);
  cJSON_AddStringToObject(root, "type", type);

 
   cJSON * payload = cJSON_CreateArray();

 
   cJSON_AddItemToObject(root,payload, cJSON_CreateNumber(129));
    cJSON_AddItemToArray(payload, cJSON_CreateNumber(33));


    // Write the array "payload" to stream.
    cJSON_AddArrayToObject(root, "payload");

 

  return root;
}

This is the JSON Iget

Thanks

RE: cJSON error

ephraim — Wed, 25 Nov 2020 07:10:49 GMT

Hi.

I have managed to insert cJSON_AddNumberToObject .

However a new error