bluetooth lowenergy - BLE: Add characteristic to a service (C++) -

i newbie in ble coding , have been struggling simple do.

i trying receive characteristic service specific uuid. experimenting ble_gap_example mbed.org.

by making slight modifications, able see device , uuid of service have assigned, unable add characteristic service.

what want achieve merely broadcast 2 values, using 2 services, each each own uuid , value. there no connection between devices.

the code simple , there no major differences sample:

#include "mbed.h" #include "ble/ble.h"  /* optional: device name, add human read-ability */ const static char     device_name[] = "g4";  static const uint16_t uuid16_list[]        = {0x2334};  /* have 26 bytes of advertising data use. */ const static uint8_t advdata[] = {0x01,0x02,0x03,0x04,0x05};   /* example of hex data */  float measurement = 10;// want broadcast.  /* optional: restart advertising when peer disconnects */ void disconnectioncallback(const gap::disconnectioncallbackparams_t *params) {     ble::instance().gap().startadvertising(); } /**  * function called when ble initialization process has failed  */ void onbleiniterror(ble &ble, ble_error_t error) {     /* avoid compiler warnings */     (void) ble;     (void) error;      /* initialization error handling should go here */ }      /**  * callback triggered when ble initialization process has finished  */ void bleinitcomplete(ble::initializationcompletecallbackcontext *params) {     ble&        ble   = params->ble;     ble_error_t error = params->error;      if (error != ble_error_none) {         /* in case of error, forward error handling onbleiniterror */         onbleiniterror(ble, error);         return;     }      /* ensure default instance of ble */     if(ble.getinstanceid() != ble::default_instance) {         return;     }      /* set device name characteristic data */     ble.gap().setdevicename((const uint8_t *) device_name);      /* optional: add callback disconnection */     ble.gap().ondisconnection(disconnectioncallback);      /* sacrifice 3b of 31b advertising flags */     ble.gap().accumulateadvertisingpayload(gapadvertisingdata::bredr_not_supported | gapadvertisingdata::le_general_discoverable );     ble.gap().setadvertisingtype(gapadvertisingparams::adv_connectable_undirected);      /* sacrifice 2b of 31b advtype overhead, rest goes advdata array define */     ble.gap().accumulateadvertisingpayload(gapadvertisingdata::manufacturer_specific_data, advdata, sizeof(advdata));     ble.gap().accumulateadvertisingpayload(gapadvertisingdata::complete_list_16bit_service_ids, (uint8_t *)uuid16_list, sizeof(uuid16_list));     //ble.gap().accumulateadvertisingpayload(gapadvertisingdata::service_data, measurement, sizeof(measurement));//when uncomment line cannot see device anymore phone       /* optional: add name device */     ble.gap().accumulateadvertisingpayload(gapadvertisingdata::complete_local_name, (uint8_t *)device_name, sizeof(device_name));      /* set advertising interval. longer interval == longer battery life */     ble.gap().setadvertisinginterval(100); /* 100ms */      /* start advertising */     ble.gap().startadvertising(); }  int main(void) {     ble& ble = ble::instance(ble::default_instance);      /* initialize ble baselayer, first! */     ble.init(bleinitcomplete);      /* infinite loop waiting ble events */     while (true) {         /* save power while waiting callback events */         ble.waitforevent();     } } 

i thoughtful on how change value of measurement dynamically in code.

thank in advance help.