Which Soft Device / SDK for lowest memory footprint

[bx]

Hi, we are using nrf51822 xxAB based module and would like to understand which SD/SDK combination is best to use in terms of memory usage. We have developed original firmware on SDK11+SD130. Is this optimal? Our needs are: 1 peripheral connection, SPIM, UART, ADC, FDS, DFU. From these FDS seems the worst performer.

Any hints much appreciated.

[endnode]

Is S130 the smallest Nordic BLE stack on nRF51 platform? No. Is it "optimal" for your project? That's hard to say because it has certain properties (e.g. support of up to 8 concurrent connection links) which you cannot get on S110 or S120. It was also supported for longer time and if there will be any critical patches to Nordic BLE stack on nRF51 (probably no new features as nRF51 will be phased out one day in favor of nRF52 and newer platforms) it will again be S130.

If NVM footprint is your main problem then one would say why the hell is anyone going in the year 2017 with nRF51 and not with nRF52? If few cents per piece is the biggest criteria then you will probably have bigger problems then just NVM size... ;)