Pointer structure with a parameter : pointer of tab

[gachet]

Hello,

I work with a XMC45 and I communicate with my PC by modbus. For that I create 2 structures :


typedef struct
{
uint32_t STATUS;
...
} Data_Modbus_Input_Register;


typedef struct
{
uint32_t HibernateCmdStatus;
chr8_t *strMsg;
...
} Data_Modbus_Holding_Register;


After I create pointer of these structures :
Input_Register = (Data_Modbus_Input_Register*)&reg_input_buffer;
Holding_Register = (Data_Modbus_Holding_Register*)&reg_holding_buffer;

At this moment all work, I can write/read with modbus.

My problem is : I would like to read a string, so i create a pointer of a tab in one of the structure "chr8_t *strMsg"
and I would like to affect it value like : "hello you"
So i write : Holding_Register->strMsg = "hello you"

But I receive "uoy".
I think it's my definition with is not good.
Someone can help me ?

Bests regards,
Pierre

 

[CodeMonkeyJ]

That definition may or may not be right. It depends on how you're assigning the string and how it's being read. It's a pointer, so it can safely point to a global static string (one written to flash). But, you can't dynamically write to it as it was not allocated any actual memory space (either "chr8_t strMsg[16]" or "chr8_t *strMsg = new chr8_t[16]"). So, it depends on how, exactly you're writing and reading it. Can you post those?