I have three models of Analog accelerometers (ADXL312, ADXL345 & ADXL362).
After reading their data sheets, I'm starting to work with them, and I have several questions I need to solve to achieve their right behaviour for my application.
First, I'm going to explain my application and the goals I want to get.
- The accelerometers need to be installed in a portable hardware platform managed by a MCU, wich reads data from accelerometers.
- MCU have to be asleep the most time possible. Only waking up when accelerometers make an interruption because of a higher vibration than the threshold level preprogrammed.
- These vibrations are low level ones, also their frequency are low. Between 1 to 100 Hz.
- Moreover, they have to work in low or ultra-low power mode (as 362 can do), to avoid unnecessary consumption.
So, here there goes my questions:
- Which are the most important parameter I have to modify to get the higher sensitivity from the accelerometers?? I'll explain better the question. I know sensitivity/scale factor are similar but is there any more factors to make more sensitive these devices (ODR, resolution...).
- How can they get the minimun vibrations levels?? Which is measurement range is the most sensitive?? (1.5g, ..., 16g)
- To work in low/ultra-low power mode, I need more info about. I don't have too much clear how I have to configure them for their right behaviour (reduce the power consumption without avoid getting measurements). Which are the registers I have to manage and how??
- I read about work with activity and inactivity interruptions in low power mode, and duration register. This could be a great solution for me, but my problem is that I don't know the real values I have to measure for the moment. The values gives back in the examples are in g's??
- One last question, about offset and gains, how are they affecting to measurement and how I can configure to better measurements?
I hope you can understand everything, but if something is not clear enough, ask me please, and I'll try to explain it better.
Thanks in advance!