Picaxe double integration?

[Jaguarjoe]

I'm baaaaaaaaaack!

My latest project is a tremorometer, a glove with three axis accelerometers on each finger tip. This will allow me to quantify how my fingers shake due to the essential tremors I suffer from.

I would like to integrate the accelerometer's signal twice to give me velocity as well as displacement data.

My question is whether to perform the integrations digitally or analogly (a new word). I've done it analogly years ago, before uC's became mainstream.

Will an 'axe do this? This all low frequency (<10Hz) stuff, amplitude can be anything I want.

I noticed that Beaniebot's "Simple battery capacity meter" did the integration analogly with that signal feeding an 08M. Maybe that's the best way? I dunno.

Any thoughts?

 

[BeanieBots]

It's certainly possible (in theory) but there will be issues over and above the basic the requirement to do the double integration.
Simply read read in the value (ReadADC) and accumulate it, then accumulate that.
The problem will be that you will VERY rapidly exceed what a word can hold. (no problem, carry over to another).
The smallest offset will result in a run-away. How will you deal with that?
The same is true for any analogue solution. You will run out of volts!

I think that if you can solve the real-life issues relating to ANY integral-of-integral, then you will be able to code that into a PICAXE assuming you don't have any resolution issues with the ADC part.

BTW: Integral of acceleration = velocity.
Double integration of acceleration = distance.
s=ut+1/2at^2
v=u+at