nRF51822QFAB Flash and RAM settings.

Question

Hello,
I am using SDK 12.2.0 with s130_nrf51_2.0.1 softdevice and running ble_app_hrs example. 
 My FLASH and RAM settings are: 
 FLASH (rx) : ORIGIN = 0x1b000, LENGTH = 0x5000
RAM (rwx) : ORIGIN = 0x20002800, LENGTH = 0x1800 
 On compiling, I get following error: 
 
 _build/nrf51422_xxac.out section .text' will not fit in region FLASH' 
 region `FLASH' overflowed by 24776 bytes 
 
 I understand the settings are wrong. 
 I am following the devzone article present here 
 Your suggestions will be appreciated. 
 Thanks.

Sigurd · Accepted Answer

Hi, 
 Your settings looks correct. The problem is that you’re using a nRF51-variant with only 128 kB flash. The S130 v.2.0.1 uses 108 kB Flash, and that leaves your application with only 20 kB free flash space. You are exceeding this limit with 24 kB. The ble_app_hrs example is just too big for a nRF51 with 128 kB flash. 
 You could e.g. upgrade to a 256 kB variant of the nRF51822. I.e. the nRF51822QFAC. You could also look into the nRF52 series . The nRF52832 have 512 kB Flash and 64 kB RAM. If cost is a major factor for you, you could look into the new low-cost nRF52810. It have 192 kB Flash and 24 kB RAM, and gives you Bluetooth 5 and nRF5-series benefits.