RE: i initialize a characteristic write-only, but that can not write,,help me!

Ulrich Myhre — Thu, 29 Oct 2015 12:33:34 GMT

You have mixed up something in your code:

BLE_GAP_CONN_SEC_MODE_SET_NO_ACCESS(&char_attr_security_mode_md.write_perm);

This sets write permission to NO ACCESS, i.e. not writable.

BLE_GAP_CONN_SEC_MODE_SET_OPEN(&char_attr_security_mode_md.read_perm);

This sets read permissions to OPEN, i.e. no access restrictions.

You probably want the opposite.

Afterwards, you also set

attr_md.write_perm = char_attr_security_mode_md.cccd_write_perm;

Which is not the write permission, but the cccd write permissions, which looks uninitialized.

Additionally, as RK mentions in a comment, you should set the proper characteristic properties to give a hint to the peer about the permissions.

RE: i initialize a characteristic write-only, but that can not write,,help me!

RK — Thu, 29 Oct 2015 06:18:01 GMT

Where in that code do you believe you set the characteristic to be writable? The only characteristic property you set true is char_props.read, so it's only readable