optical mouse motion sensor thread

[StevenB]

Originally Posted by Nibbles

My criteria was to have some tracking accuracy rate, report roughly the same velocity that is actually occurring , say, 99.9% of the time at max speed (20f/s).

I don't think 20 ft/sec will be necessary. In general maximum acceleration on the regolith will be ~1.6 ft/sec^2, meaning you'll be lucky to get over ~8ft/sec. This vastly reduces the change in focal length that is required. Some high-end mice might even be able to do it without any modification. On the other hand, there is still a robustness advantage to having the mouse more than a couple millimeters from the ground.

Interfacing one of the Avago (previously Agilent) mouse chips isn't extremely hard - I've done it before with my VEX controller. It requires only a digital IO pin and a bit of software. An oscilloscope and the datasheet go a long way.

Originally Posted by edBringas

I went to a training hosted by Team 340, one of the beta testers of the new control system and remember be told that the new Jaguar motor controllers have built in encoders. Though it takes the fun out of making encoders it should save us some time
-Ed

The Jaguars do not have built-in encoders. However, they do have support for a quadrature or analog encoder input. They have a microprocessor (more powerful than last year's controller) inside, which can run PID or other software. However, this is illegal this year per <R62>

Originally Posted by Game Manual, Section 8, <R62>

Every speed controller, relay module, and servo shall be connected via PWM cable to the
Digital Sidecar, and be controlled by signals provided from the Mobile Device Controller via
the Digital Sidecar. They shall not be controlled by signals from any other source.
A. Support for the CAN bus port on the Jaguar speed controllers is prohibited for this
competition, and the port is not to be used. Nothing shall be connected to the CAN bus
port. It is recommended that the port be protected with a piece of tape to prevent debris
from entering the port.