This is the revision B version of the Switch8 RoboBrick. The status of this project is that it has been replaced by the revision C version.

Switch8 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 Switch8 RoboBrick allows you to read up to 8 digital inputs. An interrupt can be generated on the states of selected inptus.

2. Programming

The basic operation is to send a query to the Switch8 RoboBrick to read the 8 bits of data. The programmer can download a complement mask to cause any of the bits to be complemented prior to reading.

The Switch8 RoboBrick supports RoboBrick Interrupt Protocol. The interrupt pending bit is set whenever the the formula:

L&(~I) | H&I | R&(~P)&I | F&P&(~I)]

• I is the current input bits XOR'ed with the complement mask (C)
• P is the previous value of I
• L is the low mask
• H is the high mask
• R is the raising mask
• F is the falling mask

• ~ is bit-wise complement
• | is bit-wise OR
• & is bit-wise AND

The Switch8 RoboBrick supports both the standard shared commands and the shared interrupt commands in addition to the following commands:

Command	Send/ Receive	Byte Value								Discussion
		7	6	5	4	3	2	1	0
Read Inputs	Send	0	0	0	0	0	0	0	0	Return input values abcdefgh (after XOR'ing with complement mask)
	Receive	a	b	c	d	e	f	g	h
Read Complement Mask	Send	0	0	0	0	0	0	0	1	Return complement mask cccccccc
	Receive	c	c	c	c	c	c	c	c
Read Low Mask	Send	0	0	0	0	0	0	1	0	Return low mask llllllll
	Receive	l	l	l	l	l	l	l	l
Read High Mask	Send	0	0	0	0	0	0	1	1	Return high mask hhhhhhhh
	Receive	h	h	h	h	h	h	h	h
Read Raising Mask	Send	0	0	0	0	0	1	0	0	Return raising mask rrrrrrrr
	Receive	r	r	r	r	r	r	r	r
Read Falling Mask	Send	0	0	0	0	0	1	0	1	Return falling mask ffffffff
	Receive	f	f	f	f	f	f	f	f
Read Raw	Send	0	0	0	0	1	0	0	0	Return raw data abcd (without XOR'ing with complement mask)
	Receive	a	b	c	d	e	f	g	h
Set Complement Mask	Send	0	0	0	0	1	0	0	1	Set complement mask to cccccccc
	Send	c	c	c	c	c	c	c	c
Set Low Mask	Send	0	0	0	0	1	0	1	0	Set low mask to llllllll
	Send	l	l	l	l	l	l	l	l
Set High Mask	Send	0	0	0	0	1	0	1	1	Set high mask to hhhhhhhh
	Send	h	h	h	h	h	h	h	h
Set Raising Mask	Send	0	0	0	0	1	1	0	0	Set raising mask to rrrrrrrr
	Send	r	r	r	r	r	r	r	r
Set Falling Mask	Send	0	0	0	0	1	1	0	1	Set falling mask to ffffffff
	Send	f	f	f	f	f	f	f	f
Read Interrupt Bits	Send	1	1	1	0	1	1	1	1	Return the interrupt pending bit p and the interrupt enable bit e.
	Receive	0	0	0	0	0	0	e	p
Set Interrupt Commands	Send	1	1	1	1	0	c	c	c	Set Interrupt Command ccc.
Shared Commands	Send	1	1	1	1	1	c	c	c	Execute Shared Command ccc.

3. Hardware

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

3.1 Circuit Schematic

The schematic for the Switch8 RoboBrick is shown below:

The parts list kept in a separate file -- switch8.ptl.

3.2 Printed Circuit Board

The printed circuit board files are listed below:

switch8_back.png

The solder side layer.

switch8_front.png

The component side layer.

switch8_artwork.png

The artwork layer.

switch8.gbl

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

switch8.gtl

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

switch8.gal

The RS-274X "Gerber" artwork layer.

switch8.drl

The "Excellon" NC drill file.

switch8.tol

The "Excellon" tool rack file.

4. Software

The Switch8 software is available as one of:

switch8.ucl

The µCL source file.

switch8.asm

The resulting human readable PIC assembly file.

switch8.lst

The resulting human readable PIC listing file.

switch8.hex

The resulting Intel^® Hex file.

5. Issues

The following fabrication issues came up:

• The holes for N1 are too big (size 3) and need to be made smaller (size 2).
• It would be nice to label the switches.
• Think about rotating the microcontoller by 90 degrees.