First, here's the Pen Lifter, it works awesomely well if I do say so myself...
See the blog entry
for more details.
Now for some questions;
1. The speaker makes a constant but quiet tick tick tick at about 10 hz. Is that normal?
2. Could you take a look at this code? The goal is to control the S2 using my XBee equipped remote controller. The goal is met, it does control it quite well. The problem however is that I cannot get the S2 to maintain a perfectly steady speed. It is as if every second or two the motors will stutter for just a moment even though they are receiving a steady move value.
3. Related to the above perhaps, if I stop the S2 suddenly and then very gently reverse direction, it will lurch slightly.
If I have not described the issues adequately I can put a video on YouTube.