Need to add id(derived by me) in URL of NFC module

[AKanade]

Hello,

i am using nRF52832 Development kit.

and segger embedded studio for debugging

i have just started with NFC module. i run the NFC example "record_url"  and it is working fine 

Now i want to modify this example and add the id( which is derived by me and it is uint32_t type) 

so my url look like "mysite.com/id=<id>"

suppose i have one variable 

uint32_t id = 12345;

here i want to add this id in my url 

is it possible to add this type of id in the url because as i go through the example, the url buffer is const and i have uint32_t type id value which i want to add in url.

i don't know how i can add this.

can you please help me with this.

[Jared]

Hi,

Yes this is possible. 

You would have to take in the data that you want to add and format it correctly to a

uint8_t buffer. The buffer is then passed to nfc_uri_msg_encode() to set the correct prefix and finally to nfc_t2t_payload_set(). 

regards

Jared 

[AKanade]

can i take the char buffer instead of uint8_t buffer and pass it to nfc_uri_msg_encode ?

[AKanade]

or can i do like this, will take the char buffer,
static char url[len] = "myurl"

and when pass this char buffer to  nfc_uri_msg_encode(), will simply type cast the buffer like this 

( uint8_t * )url

[Jared]

Hi,

uint8_t is just a typdef for unsigned char, it's effectively the same. You can therefore pass a unsigned char buffer instead.

regards

Jared

[AKanade]

can i initialize my unsigned char buffer like this 
static unsigned char[30] = "myurl.com/"

instead of that 
static unsigned char[30] = { 'm', 'y', 'u', 'r', 'l', '.', 'c', 'o', 'm' }

[Jared]

Hi,

I encourage you to actually try and see the result. 

Initializing it as a string will add the null character '\0' at the end of the array, which again adds this to your URL. See this link for more on the difference between a a string and char in C. 

In short: use the latter method.

regards

Jared