HID Ble Keyboard + LBS(button service) question

RE: HID Ble Keyboard + LBS(button service) question

run_ar — Wed, 04 May 2016 13:42:31 GMT

The HID example uses a whitelist when it has devices in it's device table. So other devices won't be able to connect to it. So to connect to another device you need to either purge the device table or disable the whitelist.

RE: HID Ble Keyboard + LBS(button service) question

sam — Thu, 28 Apr 2016 12:39:01 GMT

Hi,

I did another test and I found as long as the device is not reset, the button will behave normal, but with SDK9.0, if iOS's Bluetooth is turned off, the device will reset every few minutes, this will result my BLE device can't work.

I search the forum and found this reset issues is fixed in SDK11.0 and I have a test with the HID_keyboard example, it doesn't reset but SDK11.0 comes another problem, iOS7.0/9.0 can not find my BLE keyboard in Bluetooth, only iOS 8.4. is able to discover it, also SDK11.0 has only Softdevice 130, no 110, does the Softdevice version has to do with the discovery from iOS? Any idea to help?

Thanks,

RE: HID Ble Keyboard + LBS(button service) question

sam — Thu, 28 Apr 2016 06:38:19 GMT

Hi,

I use a clean hid keyboard example to do the test, and found the system goes to reset when the iPhone's Bluetooth is turned off, so i think it is not my code which causes the reset. If the system is reset, then the gatt service context my be cleared, so even I call sd_ble_gatts_sys_attr_get i get an error, actually i call dm_service_context_get and get x 0x8008 error, and when i press the button, i still get 0x3401, any help?

Thanks,

RE: HID Ble Keyboard + LBS(button service) question

run_ar — Wed, 27 Apr 2016 14:15:21 GMT

It's not. I assume you are getting an error message from a function call which is not handled and therefor defaulting to the app error handler.

RE: HID Ble Keyboard + LBS(button service) question

sam — Wed, 27 Apr 2016 14:12:48 GMT

ok I will have a look and try, but i'm curious, I just turn off the Bluetooth of iOS, how come it will cause my BLE device error and reset? Shouldn't it be just disconnected?

Thanks,

RE: HID Ble Keyboard + LBS(button service) question

run_ar — Wed, 27 Apr 2016 13:31:32 GMT

The default behavior of the app error handler is to reset your device if it is called. There is a function called device_context_store in the device manger you can use to store the data. This is usually called on the disconnected event and if there are changes to the context. You can take a look at the HID keyboard example to see how it is used there.

RE: HID Ble Keyboard + LBS(button service) question

sam — Wed, 27 Apr 2016 09:33:03 GMT

Hi,

I found i need to call sd_ble_gatts_sys_attr_get to retrieve the attr which sd_ble_gatts_hvx needs, but I have no idea how to store the data and how to retrieve it, any help?

Thanks,

RE: HID Ble Keyboard + LBS(button service) question

sam — Wed, 27 Apr 2016 09:08:19 GMT

Hi,

Thanks for your reply, I check the err_code of sd_ble_gatts_hvx and found when it is 0(no error), the button is working, and turn Bluetooth off and on again, sometime I found the whole device is reset because I output a string in main.c, and the sd_ble_gatts_hvx returns ox3401 after reset. What does that mean and can you help? the other problem is the reset, why BT turned off then on will cause my device reset?

Thanks,

RE: HID Ble Keyboard + LBS(button service) question

run_ar — Wed, 27 Apr 2016 06:58:51 GMT

Most likely iOS forgets the state of your CCCD's when you turn bluetooth off/on, so i suggest you enable it from your iOS application again. If this doesn't help please provide a sniffer trace showing the failing scenario, and also check for an error code when calling sd_ble_gatts_hvx (I would guess you are getting invalid state here).