AME 3623: Project 3: Asynchronous serial communication

A set of beacons will be provided that produce a byte sequence that encodes a unique 8-bit number.

Project Goals

To gain experience in:

Microcontroller programming
Writing programs that deal with real (and noisy) sensory data
Practice with serial protocols (including checksum computations), and bit manipulation.

Project Due Date

Deadline: Thursday, April 14th.

Task

Construct an ATMEL-based circuit that will:

Detect the packet transmitted by a beacon
Filter packets that are in error
For packets without errors: display the 8-bit number using LEDs. If no packet has been detected in the last second, then display nothing.

Bit Specification

An individual bit will be 10 msec in duration.
The "ideal" high will be encoded as a constant logic high (indicating no signal).
The "ideal" low will be encoded as an oscillation between high and low (with a period of 1 ms and a 62.5% duty cycle)

Data Frame Specification

A single byte of data will be encoded as follows:

One "0" start bit
The 8-bits within the byte (most significant bit first)
Two "0" stop bits

Packet Specification

0x4F - ascii "O"
0x55 - ascii "U"
value1 - a hex digit in ascii ("0", "1" ... "9", "A", "B", ... "F"). This value encodes the beacon identifier
value2 - a hex digit in ascii ("0", "1" ... "9", "A", "B", ... "F"). This value encodes the identifier of a second beacon
0x0A - ascii "new line" (packet terminator)
parity byte (0x4F + 0x55 + value1 + value2 + 0x0A)

Hardware

A single output line has been added to the interface board. This output line carries the raw data from the left turret sensor.

Hints

Do not dismantle your robot control circuit: add this new circuit to your existing protoboard (or use your 2nd protoboard).
Take many samples over the course of a single bit.
Use delay_ms() and delay_us() to produce the delays you will need.

What to Hand In

Project Report

Your report should include the following:

The names of the group members
A circuit diagram
A copy of your documented program (this may be handed in as a separate file).

The reports are due at 5:00 on April 14th. We prefer that these be turned in via the Blackboard drop-box (one copy per group) in either postscript or pdf format.

Personal Reports

Your personal report must include the following information:

Your name
An estimate of your contribution to the project in terms of percentage of effort.
An estimate of the contribution of each of your fellow group members.

The personal reports are due at 5:00 on April 14th. These must be turned in via the Blackboard drop-box in raw text format.

fagg at ou.edu

Last modified: Wed Mar 30 18:26:57 2005