Styjun

I am developing a code in which I need to read value from one function ("Read()") into another function ("compare") using pointer. Need to access values of "buffer" present in function "Read()". I have tried below approach, I am new with pointers implementation so not able to try much. "buffer" will have 9 elements which I have copied in "adata" in "Read()" function, need to have that data in "Compare" function.
Below is my code snippet:

 int16_t *Read (uint8_t *buffer, const uint16_t length)
 
 static uint32_t totalBytes = 0;
 static uint32_t respNo = 0;
 int i;

 GPIO_ClearValue(PMAP_GPIO_PORT_DIR_RS485, PMAP_GPIO_PIN_DIR_RS485); 

 UartRxFlush(UARW_UART_INDEX_RS485); //this function needs to be executed after the GPIO_ClearValue in order to remove the "zero" value from the buffer
 respNo++;

 int counter = 0; // counts n. valid bytes put in slave response buffer[]
 do 
 
 OSTimeDly(2);

 int8_t newBytesRcv = UartReceive(UARW_UART_INDEX_RS485,
 (uint8_t*)&(buffer[counter]), length-counter);
 totalBytes += newBytesRcv;
 counter = totalBytes;
 
 while (counter < length);

 totalBytes = 0;
 printf("n");
 printf("Byte received........");
 int16_t adata[9] = 0x09,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30; 

 for (i=0; i<9;i++)
 
 printf("%d ",buffer[i]);
 adata[i] = buffer[i];
 
 printf("n");

 

 int16_t Compare(uint8_t * message, uint16_t len)
 
 rs485_message_t rs485Msg;
 int StP15Vmsg[9] = 0x09,0x31,0x33,0x30,0x30,0x30,0x30,0x30,0x34; 
 int adata[9] = 0x09,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30; 
 uint8_t buffer[9];
 const uint8_t length;
 for (int j=0; j<=9; j++)
 
 adata[j] = *Read(buffer, j);
 
if(compareArray(FWmsg,arduinodata,7)==0)
 

 char res; 
 uint8_t add, fwcommand, fwaction;
 uint16_t fwvalue;
 rs485_message_t rs485Msg; 
 proto485ComposeMsg(&rs485Msg, &add, &fwcommand, &fwaction, &fwvalue);
 res = GetABFWversion(&add, &fwcommand, &fwaction, &fwvalue); 
 
 

Please guide....

Thank you

Note : this is not stricto sensu an 'answer' but more a list of remarks

About Read

the signature is

int16_t *Read (uint8_t *buffer, const uint16_t length)

but the function never return a value, probably you want to return the number of read bytes, in that case

int16_t Read (uint8_t *buffer, const uint16_t length)

The static variable respNo is only incremented and never used, these two lines can be removed :

static uint32_t respNo = 0;
respNo++;

There is no reason to have totalBytes static because you reset its value to 0 before to print the buffer, so there is no historic from a call to the next. It must be local.

counter is useless because it always value totalBytes

UartReceive always success and never returns a value indicating an error ?

• if yes it is useless Read returns a value because it will always be length
  


• if no you have to take into account the error and probably Read have to return totalBytes valuing the number of read bytes

In

 printf("n");
 printf("Byte received........");
 int16_t adata[9] = 0x09,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30; 

 for (i=0; i<9;i++)
 
 printf("%d ",buffer[i]);
 adata[i] = buffer[i];
 
 printf("n");

• you loop from 1 to 9 rather than from 0 to 8 so you at least go out of adata and you do not print the value of the first byte in buffer
  


• you only set adata and you never use it, it can be removed.


• the format must be %u rather than %d

Probably the loop must be from 0 to totalBytes - 1 to be compatible with the code above :

 printf("nByte received : ");

 for (i=0; i<totalBytes;i++)
 
 printf("%u ",buffer[i]);
 
 putchar('n');

About Compare

In

 rs485_message_t rs485Msg;
 int StP15Vmsg[9] = 0x09,0x31,0x33,0x30,0x30,0x30,0x30,0x30,0x34; 
 int adata[9] = 0x09,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30; 
 uint8_t buffer[9];
 const uint8_t length;
 for (int j=0; j<=9; j++)
 
 adata[j] = *Read(buffer, j);
 

rs485Msg and StP15Vmsg are useless, remove them

I do not understand why you call Read several times in the loop with a length incremented each time, so you will rewrite several times on the buffer. I do not understand too while you save the return value of Read (who do return a value currently)

Probably you want just that :

uint8_t buffer[9];
uint8_t length = Read(buffer, 9);

In

if(compareArray(FWmsg,arduinodata,7)==0)
 
 char res; 
 uint8_t add, fwcommand, fwaction;
 uint16_t fwvalue;
 rs485_message_t rs485Msg; 
 proto485ComposeMsg(&rs485Msg, &add, &fwcommand, &fwaction, &fwvalue);
 res = GetABFWversion(&add, &fwcommand, &fwaction, &fwvalue); 
 

I do not a link with the code above, and res is set but never used

Compare never does a comparison, why it is named Compare ?
It never returns a value, what value is it supposed to return ?