RE: Control a function by button and/or BLE (e.g. iOS App)

zainab_daoud — Mon, 13 Apr 2015 17:27:58 GMT

I use nRF51822 and i want to change a characteristic value(major_value) in the function button_handler? Is there any example ?

RE: Control a function by button and/or BLE (e.g. iOS App)

Ole Morten — Wed, 05 Mar 2014 09:33:59 GMT

I'm not quite sure I understand why you absolutely want to combine them, and it sounds as if what you want is more or less exactly what's covered by nAN-36 and the code here. There isn't really any problems with notifying the phone about a button press, but also using it to trigger something locally on your device. It should also be pretty easy to extens the LED state to instead write a number or something, and then using that number to control whatever action you want to happen on your device (i.e. with 0 being off, some other value being fully on, and whatever value in between being a percentage or similar).

If it is so that the local button directly controls the value, and you want to know the value also on the phone, I'd recommend to instead just remove the button characteristic, and just notify the value when it changes.

Also, for completeness, there isn't really anything stopping you from having a characteristic that's both readable, writeable and notifiable. You can do this by just setting all the needed properties in the ble_gatts_char_md_t struct when initializing the characteristic. You can then both do notifications with sd_ble_gatts_hvx(), set the value to be read with sd_ble_gatts_value_set() or receive writes over-the-air.