OK., decision made… No more toy motors and fighting to get makeshift encoders working. Bought four FIT0483‘s from DigiKey they should be in tomorrow. Society of Robots helped with the selection. Not a cheap solution but a workable one.
Started working on the concept for Rover II.
Three Tiers.
Bottom tier is for batteries and motor controllers. This is to keep the center of gravity as low as possible. The motors will be mounted on the underside of this tier.
Giving me lots of clearance underneath. The revised bumper will be mounted at the front and resolves Rover I’s problem with chair legs. Where encountering one in the center would not trigger an avoidance maneuver.
The second tier will house the brains. At present, I’m thinking one Raspberry Pi 3 B and one or two Arduino Nano’s. The Master Nano will manage all peripherals (motors, sensors, servos, etc). The ancillary Nano might be necessary to get the pin level up and to handle some of the dumb sensors. At the front of this tier I have two ranging sensors whose direction is controlled by servos. The ultrasonic sensor (left side) will be able sweep from right of forward to back of left. It will be employed in wall following. The infrared sensor (right side) will be mounted on a Pan and Tilt from Adafruit. This will be able to sweep from left to right, and can be tilted down to look for approaching table edges.
The upper tier is primarily to support the monitor and control panel. This is a simple 2X16 character display, a set of six buttons, and a sprinkling of LEDs. There will be room for any other peripherals that may make themselves necessary (radio transceiver, environmental sensors, and so on).
The material for much of Rover II will be Sintra, thanks to Albert from the local “Ottawa Robotics Enthusiasts” (ORB) group.
Newbury Pi 