Hi ,I am using nrf52 DK with mpu9255.I am using source code given here here.of this link,I have taken 'nrf5-ble-data-ready-interrupts' example .code builts fine in keil v5 though.I am not getting accel values.
I have pushed an updated 'nrf5-ble-data-ready-interrupts' example to github that I have tested with a PCA10056 and an MPU9255.
Note that to use pin 17, 19, 20, and 21 on the PCA10056 you will need to cut some solder bridges and do some soldering as these pins are not actually connected to the P24 header on the kit by default (as is described in the image you have posted): Solder bridge configuration.
If you look on the back side of your kit you can see which pins are already being used for things like UART. In the MPU examples the UART are configured before the MPU in the code. If you "override" the UART configuration and use the UART pins for the MPU then naturally you will not see anything printed to your terminal. This is why I chose to use pin 3,4,28,29 and 30 by default in the examples since they are not being used by anything else.
2.Data is sent directly when i enable the notification after connection to device .what changes do i need make if i want to send data only after i write a value to characteristic ?
what changes do i need make if i want to send data only after i write a value to characteristic I advice you to study the BLE Blinky Application example. It shows how you can turn on an LED by writing to a characteristic. With a little modification you can use this to achieve what you want.
