How to implement 512 bytes characteristic in peripheral

[Paul]

Do we have any example for implementing a characteristic with more than 20 bytes? Thanks.

[RK]

Example? Just set the length of the characteristic to what you want when you add it.

ble_gatts_attr_t.max_len
ble_gatts_attr_t.init_len

and note the defines

#define BLE_GATTS_FIX_ATTR_LEN_MAX (510)  /**< Maximum length for fixed length Attribute Values. */
#define BLE_GATTS_VAR_ATTR_LEN_MAX (512)  /**< Maximum length for variable length Attribute Values. */

[RK]

Central doesn't know nor care whether the property is fixed or variable length, it's not something reported as a property of the characteristic. The central, when reading, will just read at ever larger offsets until it gets a shorter than MTU packet or a response saying there is no data at that offset.