This is the Revision A version of the PIC876Hub10 RoboBrick. The status of this project is work in progress.

PIC876Hub10 Robobrick (Revision B)

Table of Contents

This document is also available as a PDF document.

• 1. Introduction
• 2. Programming
• 3. Hardware
  • 3.1 Circuit Schematic
  • 3.2 Printed Circuit Board
• 4. Software
• 5. Issues

1. Introduction

The PIC876Hub10 RoboBrick is a master RoboBrick that can control up to N slave RoboBricks. It uses a PIC16F876 microcontroller from MicroChip^®. One of the hub ports can be connected to a communications RoboBrick to provide the ability to talk to the development platform.

There is a three terminal connector, one for ground and the other two for power. One power connector is connected to a standard 3-terimal 5 volt regulator to provide 5 volts to the slave RoboBricks. The other power regulator is only sensed for voltage level. The microcontroller has a built in analog to digital converter that allows it to sense the power level on both power terminals. When the power goes below a preset level, the robot platform can choose to enter a `hungry' behavior mode.

2. Programming

There is no programming specification for the PIC876Hub10 RoboBrick yet.

3. Hardware

The hardware consists of a circuit schematic and a printed circuit board.

3.1 Circuit Schematic

The schematic for the PIC876Hub10 RoboBrick is shown below:

The parts list kept in a separate file -- pic876hub10.ptl.

3.2 Printed Circuit Board

The printed circuit board files are listed below:

pic876hub10_back.png

The solder side layer.

pic876hub10_front.png

The component side layer.

pic876hub10_artwork.png

The artwork layer.

pic876hub10.gbl

The RS-274X "Gerber" back (solder side) layer.

pic876hub10.gtl

The RS-274X "Gerber" top (component side) layer.

pic876hub10.gal

The RS-274X "Gerber" artwork layer.

pic876hub10.drl

The "Excellon" NC drill file.

pic876hub10.tol

The "Excellon" tool rack file.

4. Software

There is no software for this RoboBrick yet.

5. Issues

The following fabrication issues came up:

• The switch needs to be replaced with a physically beefier switch that does not disintegrate after a few hundred switch throws. The Jameco 109170 SPDT slide switch is the current best candidate. It only supports .5Amp of current though.
• Consider loosing the crystal oscillator chip and replacing with a crystal and a couple of capacitors. Perhaps use a ceramic resonator instead.
• It may be necessary to make the shorting diode go vertical to make room for the larger switch footprint.