BLE-NRF51822 Tutorial 8-Dynamic Broadcast_PHP Tutorial

BLE-NRF51822 Tutorial 8-Dynamic Broadcast

This tutorial teaches how to implement dynamic broadcast in reception.

The tutorial is based on the Uart example in the 9.0 sdk.

The way to implement dynamic broadcast is broadcast->stop broadcast->modify parameters->restart broadcast

So We use a timer to periodically turn off broadcasting and then modify the broadcast data before turning on broadcasting.

The broadcast in SDK 9.0 has several modes, which is a bit troublesome, so I made relatively big changes to it.

First of all, the advertising_init function in main.c needs to be changed.

The main modification also added the red part. Change flag to GENERAL. Later, the broadcast timeout is set to 0 to implement wireless broadcast.

The function to set broadcast data according to the broadcast mode and the setting of scan response data have been removed.

void advertising_init(void)

{

uint32_t err_code;

ble_advdata_t advdata;

ble_advdata_t scanrsp;

memset(&advdata,0, sizeof(advdata));

advdata.name_type = BLE_ADVDATA_FULL_NAME;

advdata.include_appearance = false;

advdata.flags =BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;

staticble_advdata_manuf_data_t manuf_data;

staticuint8_t mydata = 0; //Static data is used here

//The dynamic broadcast done here is Each time this function is called

//number, the manufacturer-defined field in the broadcast data will be incremented by 1

manuf_data.company_identifier= 0xffaa;

manuf_data .data.size= 1;

manuf_data.data.p_data= &mydata;

mydata; //Add 1 after each call

advdata .p_manuf_specific_data= &manuf_data;

err_code= ble_advdata_set(&advdata, NULL);

APP_ERROR_CHECK(err_code);

}

Then start the broadcast function. The Main function uses ble_advertising_start.

We don’t use it here. Directly implement a simple function of your own

void myadv_start(void){

ble_gap_adv_params_tadv_params;

adv_params.interval =1600; //The broadcast interval here is set to 1s

adv_params.timeout = 0; //Set 0 here and cooperate with the above flag to implement wireless broadcast

adv_params .type =BLE_GAP_ADV_TYPE_ADV_IND;

adv_params.channel_mask.ch_37_off= 0;

adv_params.channel_mask.ch_38_off= 0;

adv_params.channel_mask.ch_39_off= 0;

adv_params.type = BLE_GAP_ADV_TYPE_ADV_IND;

adv_params.p_peer_addr= NULL;

adv_params.fp = BLE_GAP_ADV_FP_ANY;

adv_para ms.p_whitelist= NULL ;

sd_ble_gap_adv_start(&adv_params);

}

After that we make a timer. The function of the timer is to close and modify the broadcast parameters in a 2s cycle and then start the broadcast

Do it in the main function Modify as follows, create a 2s timer my_timer, and enable it

int main(void)

{

uint32_t err_code;

bool erase_bonds;

uint8_t start_string[] = START_STRING;

app_timer_id_tmy_timer;

// Initialize.

APP_TIMER_INIT(APP_TIMER_PRESCALER, APP_TIMER_MAX_TIMERS, APP_TIMER_OP_QUEUE_SIZE, false);

uart_init();

app_timer_create(&my_timer,APP_TIMER_MODE_REPEATED,

my _timer_handler);

buttons_leds_init(&erase_bonds);

ble_stack_init();

gap_params_init();

services_init();

advertising_init();

conn_params_init();

app_timer_start(my_timer,APP_TIMER_TICKS(2000,APP_TIMER_PRESCALER), NULL);

myadv_start(); //The self-defined start broadcast function used here

for (;;)

{

power_manage();

}

}

Then implement your own timer overflow handling function

void my_timer_handler(void *p_contex){

int i =50;

sd_ble_gap_adv_stop(); //Turn off broadcasting

advertising_init(); //Modify data in manufacturer-defined fields

while(i--) ;

myadv_start(); //Start broadcast

}

The dynamic broadcast done here is to dynamically modify the manufacturers in the broadcast data Custom fields. Each time the

advertising_init function is called, the value of the manufacturer's custom field will be incremented. There are comments in the advertising_init function

What needs to be done for dynamic broadcasting here has been done It's over.

However, we need to make a change in the uart example. We created a timer of our own, but the maximum number of timers allowed to be used defined in the uart example is the number it has already used, so we add our own The timer will be wrong.

Modification method: Find the APP_TIMER_MAX_TIMERS macro in the main.c file and increase it by 1.

After the burning program, you can see that the manufacturer-defined fields in the broadcast data have changed dynamically