This is the Revision A version of the SonarDT1 RoboBrick. The status of this project is that it has been replaced by the revison B version.

SonarDT1 Robobrick (Revision A)

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 Sonar1 RoboBrick is used to provide a RoboBrick interface to the SRF04 sonar range finder from Devantech.

2. Programming

The SonarDT1 RoboBrick is focused on operating the Devantech SRF04. In addition, it has the ability to control 1 servo, so that the SonarDT1 RoboBrick can be mounted on a standard hobby servo as a scanning platform. Lastly, there are some LED's that can provide direct feedback on the current distance being measured by the SRF04.

The SonarDT1 commands are summarized in the table below:

Command	Send/ Receive	Byte Value								Discussion
		7	6	5	4	3	2	1	0
Read Distance Low	Send	0	0	0	0	0	0	0	0	Return the low order byte llllllll of the distance
	Receive	l	l	l	l	l	l	l	l
Read Distance High	Send	0	0	0	0	0	0	0	1	Return the high order byte hhhhhhhh of the distance
	Receive	h	h	h	h	h	h	h	h
Read Distance High and Low	Send	0	0	0	0	0	0	1	0	Return the low and high order bytes llllllll hhhhhhhh of the distance
	Receive	l	l	l	l	l	l	l	l
	Receive	h	h	h	h	h	h	h	h
Trigger Distance Measure	Send	0	0	0	0	0	0	1	1	Trigger a Single Distance Measurement
Disable Servo	Send	0	0	0	0	0	1	0	0	Disable Servo
Enable Servo	Send	0	0	0	0	0	1	0	1	Enable Servo
Disable Continuous Measurement	Send	0	0	0	0	0	1	1	0	Disable Continuous Measurement
Enable Continuous Measurement	Send	0	0	0	0	0	1	1	1	Enable Continuous Measurement
Increment Servo	Send	0	0	0	0	1	0	0	0	Increment servo position by one.
Decrement Servo	Send	0	0	0	0	1	0	0	1	Decrement servo positon by one.
Read Servo	Send	0	0	0	0	1	0	1	0	Return servo value ssssssss of the distance
	Receive	s	s	s	s	s	s	s	s
Read Enables	Send	0	0	0	0	1	0	1	1	Return servo enable s and continuous distance measurement m
	Receive	0	0	0	0	0	0	m	s
Set Servo Low	Send	0	0	0	1	l	l	l	l	Set the low order 4 bits of the servo position to llll.
Set Servo High	Send	0	0	1	0	h	h	h	h	Set the high order 4 bits of the servo position to hhhh.
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 Sonar1 RoboBrick is shown below:

The parts list kept in a separate file -- sonardt1.ptl.

3.2 Printed Circuit Board

The printed circuit board files are listed below:

sonardt1_back.png

The solder side layer.

sonardt1_front.png

The component side layer.

sonardt1_artwork.png

The artwork layer.

sonardt1.gbl

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

sonardt1.gtl

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

sonardt1.gal

The RS-274X "Gerber" artwork layer.

sonardt1.drl

The "Excellon" NC drill file.

sonardt1.tol

The "Excellon" tool rack file.

4. Software

The software for the SonarDT1 RoboBrick is in the following files:

sonardt1.ucl

The µCL source code.

sonardt1.asm

The PIC16F628 assembly code.

sonardt1.lst

The listing file.

sonardt1.hex

The Intel^® hex file.

5. Issues

The following fabrication issues came up:

• Try and find 5-pin female connector vendor.
• Think about adding another LED to one of the unused pins.
• Think about adding an in-line programming capability!