Embedded C project with nRF52

I am working on a nRF52 project where MPU-9250 is connected with i2c interface and (ssd1331) display will be connected via spi. Project Details Initial Setup: Once the device is connected, mobile will pass struct data to do initial set up. This data will be: • Name of device: 15 Chars long • Unique ID: A uuid • Current Time Device Name and unique id will be stored in some permanent store like eeprom so it does not get erased on device disconnection or firmware update. Connection: Device needs to be bonded with the mobile phone. When mobile detects this device user will click on connect button on mobile and on IOT device user have to press the button down and hold it down till it gets connected. As Mobile will recognise the service uuid of this IOT so it will bond. If bonded it should connect next time automatically. On every connection mobile will send current time. This time will be displayed on the OLED (SSD1331). Once the time is sent to nrf52 this time will be kept upto date via some timer etc. So in case the device gets disconnected OLED keeps displaying time correctly. MPU-9250: Service 2 will be responsible for sending mpu-9250 data to mobile. Also we will display the data displayed on OLED (SSD1309). We will have struct of acceleration, gyration, magnetometer and angle. We will need to show smooth data by doing filtering and data averaging. There are articles online which tells how to do this for Arduino but we can use that technique for nrf52. Over the air firmware update: Firmware should be updated via over the air. Your expert help is needed in creating low power design.