Not sure if this will work but if you say you have 2 speed settings that you can use from the standard PWM then maybe you can interpolate between them by switching between them according to the ratio you want. For instance like (SPEED 1, SPEED 2, SPEED 1, …) should give a setting somewhere halfway between SPEED 1 and SPEED 2, and (SPEED 1, SPEED 1, SPEED 2, SPEED 1, SPEED 1, SPEED 2, …) should give a setting somewhere about SPEED1 + 1/3*(SPEED 2 - SPEED 1)
Did that make any sense? Of course this will eat more clock cycles so maybe it won’t do any good at all.
I’m going to use regular DC motors for the Mark II. Take a look for info on alternative options for driving steppers. I read somewhere that some guy gets really good control by chanhing the length of the LOW part of the PWM instead of the (more typical) cahnging of the “high.”
SPEED1, etc. means nothing to me. I see what you mean, though. Chopping between speed 1 and speed 2 would give a halfway house. I hadn’t considered it because on a regular servo that would produce a really bumpy movement and holding signal. However, on a continuous rotation servo, it might work. Unfortunately now I’m committed to a DC motor solution. I think I’ve taken servos about as far as I can.
Very interesting I like it I too have gave omniwheels a shot but put it on the shelf for a while. I have looked into 3 and 4 wheel versions and will probally stay with 4. I like your wheels. They actually appear to work. I have seen them from another post in the parallax forum and u tube videos. I guess I will have to wait until I can get some wheels. My omniwheel growbot will have to collect some more dust until then. You are on the right path. A video speaks 1,000 words. Stay wit Dc motors. In my opinion, stepper motors are not worth the battery weight they have to carry. Very inefficient. I have 4 laying around with driver chips if anyone interestted. Anything that gets hot just sitting there is not good on low power batterys. Adding relays and junk is just going into reverse technoligy.
I am also following this I still think the 4 wheel system is much easier but I stopped until I can get some better wheels. Here is link that got me started. It has all been somewhat engineered before. Notice the wheels. http://www.societyofrobots.com/robot_omni_wheel.shtml
