Including an accelerometer in your system is easy these days, right? Heck, they can trigger interrupts in your processor, so just toss it in, wait for the fateful interrupt, and let your handler do the rest. Right?
Actually… no. There are numerous controls that you have – and will likely want to take advantage of – to optimize how your accelerometer works. Those settings have a significant impact on noise and power. Sampling rate is a good example: the faster you sample, the more accurate your reading will be (i.e., lower noise). But that also increases power consumption. There are a whole slew of registers in the accelerometer that contain all of the settings, and the datasheets tell you how to get to each one.
Problem is, you mostly need to do that through code, typically. That can mean iterating through your start-up code, for example, to load different values and see what happens. And that last bit is important: you might actually have to exercise the thing to figure out where the best balance is. Lots of back-and-forth changing settings, measuring, rinsing, and repeating.
The other alternative has been to use an accelerometer that has been simplified, with a few crude settings that may or may not represent the best mix for your system.
Kionix recently announced a tool to provide easier access to the fine-grained detail in their accelerometers. The idea behind this FlexSet Performance Optimizer is to make detailed adjustments almost as easy as the crude ones on simplified accelerometers.
At the first level, this is a GUI into the register set. So at the very least, it’s easy to see and change register values. At the next level, the tool will provide information on the power and noise implications of your settings – meaning you don’t need to exercise the thing to figure out the impact of your selected settings. And at yet a higher level, you can do side-by-side comparisons of different cases.
The hooks for this are built into their latest accelerometers and will support new ones going forward. The GUI itself can be downloaded or run on the internet. (Presumably the one on the internet won’t actually set the settings in your accelerometer, just figure out what those settings should be. Unless, I suppose, you’ve connected your accelerometer to the internet…)
You can find more in their release.