MIDI BLE Example NRF52DK

[Remo]

Hi. I am new with KEIL MDK and Nordic and ARM ..... I will create an MIDI BLE, but maybe anybody has an working Example for this? Or what for an Example i can modify?

Thanks Remo

[Stian Røed Hafskjold]

Which version of the SDK are you using? SDK version 12.x.0 uses SoftDevice 3.0.0, and version 11.0.0 uses SoftDevice 2.0.x. The ble_app_uart example is working out of the box. Please follow the instructions here: infocenter.nordicsemi.com/.../ble_sdk_app_nus_eval.html.

Examples in the ble_peripheral folder requires the SoftDevice, and examples in the peripheral folder does not require the SoftDevice. Do a full chip erase in nRFgo Studio before you flash the non-SD examples.

How do you know that the example is not running? The BLE examples are also blinking a LED to show that they are advertising.

Are you using Keil to compile and flash the examples? Have you configured the debugger correctly in Keil? Got to Options->Debug, Use: JLink. Go to Settings and choose the right debugger, and SWD interface.

[Stian Røed Hafskjold]

Also, are you using nRF52 or nRF51? nRF51 requires a different Softdevice (s130) and you need to open the examples in the pca10028 folder. Which development kit are you using?

[Remo]

Long time ago i work on the issue. Now i have an stable working MIDI BLE communication. But i issue i cant find out. When i Play an midi File from (iMac or iOS or anything) the Play is not time stable. I try to explain. When i send every 100ms an Drum Sound as Example. so is every 5to10 Sounds an delay of exact 20ms. I hope someone can help me. I use the Keil SDK with the s132_nrf52_3.1.0 Softdevice

[Stian Røed Hafskjold]

What is the connection interval you are using? If the connection interval is 20 ms and you send a sample every 100ms, maybe some of the samples are arriving to late, and is pushed over to the next connection interval? You can try to set the connection interval to 7.5 ms which is the shortest according to the BLE spec.

[Remo]

Oh wow, yes this is much better. Now i need to find out how i can made it with 1ms latency. For this will the midi BLE send an time Stamp. Many thanks Stian