1. Overview and Design

Consistent with the Robot50 objectives, Bootstrap is an inexpensive
learning tool. It requires soldering. fabrication, and programming. It provides a base for modification and upgrading.

Bootstrap is a small (about 130mm) round, wheeled robot that is designed to operate autonomously. The round design helps to prevent it from getting hung up while turning. The design of Bootstrap makes it suitable for indoor use in most environments. It will struggle on deep pile carpet. Outdoors it should operate on smooth concrete or blacktop, although it will be a bumpy ride. It can handle a moderate number of additional sensors at one time but is not designed for more than a few ounces of additional weight.

The basic model can be built from plans, design files, and instructions on this site for around $50. Bootstrap can be upgraded with better batteries, many additional sensors (pretty much anything that can be controlled by an Arduino) and connectivity options such as Bluetooth.

The micro controller is an Arduino Nano. It also utilizes the following major components in its basic configuration:

DRV8835 dual motor driver (in a Pololu carrier)

5V boost converter/regulator

Protostack small protoyping board

piezo buzzer

N20 gear motors

2 “bump” switches

HC-SR04 Ultrasonic sensor

3xAA Alkaline, 3xAA Nimh, or single cell LiPo battery

3D printed or hand fabricated chassis and structural components.

The whole system runs at 5 volts via the boost converter. This allows a variety of battery sources (3 alkaline or nimh AA batteries or a single cell LiPo pack) and keeps sensor selection simple. All fasteners are m2x12mm screws. Many components can be 3D printed but all components can be purchased from common sources. 3D printing is not required to build Bootstrap.

Prototype 3Prototype 3 bottom
Prototype 3 bottom