How to make 'without response' in nus rx characteristic?

[Manuel Kwong]

Hi,

In my application, I am using nus service with S110 V7.1.0 (nRF51822). I faced to one problem that the rx channel is set up to notify characteristic. In iOS (8.3), it is often blocked when it sends out data to the nus channel to the device.

The tx channel in the device has no problem and very smooth even the data rate is boosted to very high. However, in the rx channel, it cannot receive the data sometime and the whole communication is blocked up. The Bluetooth stack returns timeout error when iOS apps wants to send out data to the device via the nus rx channel (device).

In the tx channel,it is set to write without response but in rx channel, it is set to notify.

Question : can the rx channel be set up to be without response so that it is much more smooth?

[Carles]

Hi there,

Notifications and Write without Response follow the exact same flow control mechanisms, so the speed should be roughly the same.

I am not sure what is going on here, maybe someone from the SDK team will be able to take a look.

Carles

[Hung Bui]

@Manuel: Are you sure you used our nus service without notification ? In our implementation the server is on the nRF51. So when the iOS device wants to send data from the phone to the nRF51 it will do a write command (write without response) on the tx characteristic. When the device want to send data to the iOS device, it will do a notification.

Note that you can only do write without response from the client to the server. So if you want to do write without response from the nRF51 to the phone, you would need to implement the server on the phone.

[Manuel Kwong]

May be simply to ask and worth to test with : How to change the rx channel in nRF51 device to "write without response"?

[Manuel Kwong]

May be simply to ask and worth to test with : How to change the rx channel in nRF51 device to "write without response"?

[Carles]

There are no "channel" but instead you have a characteristic, and notifications are used by a server to send updates to the client. If you want to instead be a client and send write without response to a server, your server (peer device) must have a characteristic that you can write to.