ble data transfer

[Siva]

Hi,

I am using the following statements for send a string data over BLE.

static uint8_t Name3[BLE_NUS_MAX_DATA_LEN]= "xxxxxxxx";
	err_code = ble_nus_string_send(&m_nus, Name3, 20);	
	if (err_code != NRF_ERROR_INVALID_STATE)
	{
		APP_ERROR_CHECK(err_code);
	}	

But I am unable to send integers and floating values. Is there a function where I can send non-string data variables via BLE.

Regards Siva

[awneil]

I am unable to send integers and floating values

What did you actually try?

The Nordic UART Service - like a real UART - actually just sends bytes: it neither knows nor cares whether those bytes are to be interpreted as a string, an "integer" (whatever that might mean), a "floating value" or whatever.

The documentation is here:

developer.nordicsemi.com/.../a01011.html

You just tell it where the data starts (that's the pointer), and how many bytes to send ...

[RichieJH]

So assume you want to send a uint16_t value of say 10000. This is of course two bytes and you must assign each byte of value to each element of the array Name3. One fairly easy way to do this is bit masking and shifting. So do this:

Name3[0] = (value & 0xFF00) >> 8;
Name3[1] = (value & 0x00FF);

Now say value was a unit32_t, which is 4 bytes long, then do this

Name3[0] = (value & 0xFF000000) >> 24;
Name3[1] = (value & 0x00FF0000) >> 16;
Name3[2] = (value & 0x0000FF00) >> 8;
Name3[3] = (value & 0x000000FF);

[awneil]

That won't work - you can't just do

 Name3[1] = uint32_t some_int; 
 Name3[5] = uint16_t something_else; 

You have to copy each byte individually

[RichieJH]

You do not have to copy each byte individually and this does work.

unint32_t some_int = 100; Name3[0] = some_int;

The next 4 bytes in the array will be taken up with some_int with the value of 100. Not the most efficient way to store the value of 100, but the principle works. Remember Name3 is a Uint8_t array.

[awneil]

No! that is not the way 'C' works!!

When you assign to Name3[x] you are just assigning to that one element - using the standard 'C' conversion rules if the RHS of the assignment is not the same type as the LHS.

It does not run-on to subsequent elements in the array!!