I'm getting this question more frequently than others on my previous post about ADXL345 and Arduino, so I've decided to answer it with a post of itself. So, how do you connect and read from two ADXL345s with a single Arduino board? It's pretty straight forward if you already have one ADXL345 running. If you don't, head here, set everything up and get back here because I'll be assuming that you have read it and familiar with the concepts from the previous post.