i want to know is there an inbuilt accelerometer in dragon Board 410 c?
if not then can we connect it externally?
I don’t believe there is an accelerometer built-in.
Attaching an external one is certainly possible though. Using an I2C sensor would be best (use the audio mezzanine if you need level shifting to connect it).
Alternatively you could take a look at the Neonkey mezzanine. This has a built in accelerometer (together with many other sensors) although I don’t think there are any tutorial guides on how to connect it to the DB410C.
I have used the following with Dragonboard 410c as it works directly with 1v8 GPIO:
It has the downside of being quite small and fiddly to solder. Although you can get it mounted in a DIL24 format:
I have used Python to interact with it if you are looking for an example: