Initializing Cycling Power Service 0x1818

[Juan Moya]

Hello!

I am trying to implement the Cycling Power from https://devzone.nordicsemi.com/f/nordic-q-a/9169/cycling-power-service-0x1818

Please, could you show how we need to configure the service?
This way is not working:
memset(&cp_init, 0, sizeof(cp_init));
            
            cp_init.ctrlpt_evt_handler    = NULL;
            cp_init.feature                     = BLE_CPS_FEATURE_WHEEL_REV_BIT | BLE_CPS_FEATURE_CRANK_REV_BIT | BLE_CPS_FEATURE_MULTIPLE_SENSORS_BIT;
            
            // Here the sec level for the Cycling Speed and Cadence Service can be changed/increased.
            BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cp_init.cp_meas_attr_md.cccd_write_perm);   // for the measurement characteristic, only the CCCD write permission can be set by the application, others are mandated by service specification
            BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cp_init.cp_feature_attr_md.read_perm);      // for the feature characteristic, only the read permission can be set by the application, others are mandated by service specification
            
            
            //cp_init.ctrlpt_evt_handler            = sc_ctrlpt_event_handler;
            
            
            err_code = ble_cps_init(&m_cp, &cp_init);
            APP_ERROR_CHECK(err_code);

[Juan Moya]

Hello,

I am trying to initialize the service Power Cycling from the files of this link https://devzone.nordicsemi.com/f/nordic-q-a/9169/cycling-power-service-0x1818

I get the CSC example from Nordic and I tried to initialize the service of Power Cycling from the files that I downloaded.
That's all

[Susheel Nuguru]

the code does not compile with SDK15 and SDv6.0.0. Can you tell me which versions are you using so that i can give it a try

[Juan Moya]

Hello,

 

You can get the example of Nordic --> ble_app_cscs with s132_nrf52_2.0.0-7.alpha_softdevice

 

[Susheel Nuguru]

in services init you call this

    ble_cps_init_t        cps_init;
    
    // Initialize Cycling Power Service module
    memset(&cps_init, 0, sizeof(cps_init));

    cps_init.evt_handler = NULL;
    cps_init.feature     = BLE_CPS_FEATURE_WHEEL_REV_BIT | BLE_CSCS_FEATURE_CRANK_REV_BIT |
                            BLE_CSCS_FEATURE_MULTIPLE_SENSORS_BIT;

    // Here the sec level for the Cycling Speed and Cadence Service can be changed/increased.
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cps_init.cp_meas_attr_md.cccd_write_perm);   // for the measurement characteristic, only the CCCD write permission can be set by the application, others are mandated by service specification
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cps_init.cp_feature_attr_md.read_perm);      // for the feature characteristic, only the read permission can be set by the application, others are mandated by service specification
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cps_init.cp_ctrlpt_attr_md.write_perm);      // for the SC control point characteristic, only the write permission and CCCD write can be set by the application, others are mandated by service specification
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cps_init.cp_ctrlpt_attr_md.cccd_write_perm); // for the SC control point characteristic, only the write permission and CCCD write can be set by the application, others are mandated by service specification
    
    cps_init.ctrplt_supported_functions    = BLE_SRV_SC_CTRLPT_CUM_VAL_OP_SUPPORTED
                                              |BLE_SRV_SC_CTRLPT_SENSOR_LOCATIONS_OP_SUPPORTED
                                              |BLE_SRV_SC_CTRLPT_START_CALIB_OP_SUPPORTED;
    cps_init.ctrlpt_evt_handler            = sc_ctrlpt_event_handler;
    cps_init.list_supported_locations      = supported_locations;
    cps_init.size_list_supported_locations = sizeof(supported_locations) / sizeof(ble_sensor_location_t);            
    
    sensor_location           = BLE_SENSOR_LOCATION_FRONT_WHEEL;                    // initializes the sensor location to add the sensor location characteristic.
    cps_init.sensor_location = &sensor_location;
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&cps_init.cp_sensor_loc_attr_md.read_perm);    // for the sensor location characteristic, only the read permission can be set by the application, others are mendated by service specification

    err_code = ble_cps_init(&m_cps, &cps_init);
    APP_ERROR_CHECK(err_code);

in ble_srv_common.h file you add below

#define BLE_UUID_CYCLING_POWER                                   0x1818     /**< Cycling Power UUID. */

#define BLE_UUID_CYCLING_POWER_MEASUREMENT_CHAR                  0x2A63     /**< Cycling Power Feature characteristic UUID. */
#define BLE_UUID_CYCLING_POWER_FEATURE_CHAR                      0x2A65     /**< Cycling Power Measurement characteristic UUID. */

I guess that should be enough.

[Juan Moya]

Hello Aryan,

Thanks in advance.

But it doesn't work. I can connect with device as Speed & Cadence but I can not see the Power Cycling.

[Susheel Nuguru]

I just tried to run this code and the CP service does show up along with CSC

[Juan Moya]

Hello Aryan,

Did you modify the files ble_cp?

[Susheel Nuguru]

Hi Juan,

I did not touch them. I only modified main.c and added few defines in ble_srv_common.h.

I am home already, so I can attach you my whole project tomorrow if you think that will help you. I tested this on SDK 11.

[Juan Moya]

Hello,

Now I am trying to change the value of power:

cps_measurement.power_measurement = 1000;        
            err_code = ble_cps_measurement_send(&m_cps, &cps_measurement);
            err_code_CPS = err_code;
                if ((err_code != NRF_SUCCESS) &&
                        (err_code != NRF_ERROR_INVALID_STATE) &&
                        (err_code != BLE_ERROR_NO_TX_PACKETS) &&
                        (err_code != BLE_ERROR_GATTS_SYS_ATTR_MISSING)
                        )
                {
                        APP_ERROR_HANDLER(err_code);
                }

But an error jumps:  NRF_ERROR_INVALID_STATE

I see that it is because if (p_cps->conn_handle != BLE_CONN_HANDLE_INVALID){ in ble_cps_measurement_send.

I see that you initialize cps_init.evt_handler = NULL; in the init_services.

Do you undestand why it happens?