I have been using mbed and BLE to develop with for awhile now. I just gave mbed OS a try and here are my thoughts. The nrf51822 build process is very finicky with all the softdevices and 16/32k variants. mbed OS doesn't really solve this problem, but it does make it easier to deal with using the different targets. 'yotta build' takes around 30 seconds to complete a main.cpp only rebuild, whereas my Makefile project finished in a second or two. yotta is a very nice tool to update your project to the latest sources and to create al new project.Updating existing yotta projects seems liable to break working code though. Speaking of updates, I noticed that Nordic SDK 11 has removed support for S110 and S120 devices, and has released an alpha version 2 for S130. I think the removal is a good thing for the most part. I wonder how long before support for S110 in this project is phased out. It seems to me that mbed OS doesn't really provide much to a BLE-only device. minar just seems to be a renamed named ticker. I realize it does more than that, but for the most part I don't see much of a practical difference. I wonder if it uses the LF clock as its source like this project does. Those were just some thoughts I've had while looking through mbed OS and I thought I'd share them as it seems that is the way things are headed on mbed.