FPGA-based Wireless Robotics Controller for Evolutionary Design

Conor Doyle

Supervisor: Dr. Fearghal Morgan

Introduction

• The focus of this project is to develop a wireless interface between a 68HC11 (Handy board) microcontroller and a Virtex II pro FPGA containing a powerpc processor. The objective of this project is to create a fully autonomous robot that is controlled by an evolved controller contained on the Virtex II FPGA.

Virtex II Pro

HandyBoard

Motor 1

Motor 2

Sensor 1

Sensor 2 Sensor 3

Sensor 4

Octobot Robot

PPC Processor

Evolved Robot Controller

Radiometrix RPC

Radiometrix RPC

Sensors – SHARP GPD120 IR sensor

Wireless device – Radiometrix FRPC2-433-160

FPGA-based Wireless Robotics Controller for Evolutionary Design

Steps in project

1. Hardwired communication between PowerPC (on Xilinx VII Pro) and PC host

Serial Port

Functions:(i) Display message “Hello World” on host PC terminal.(ii) Host PC control of XUP board LEDs.(iii) XUP switch control of Host

Powerpc

Push Button Switchs

LEDs

DIP Switchs

Virtex II Pro

Motor 1

Motor 2

Sensor 1

Sensor 2

Sensor 3

Sensor 4

Octobot Robot

Serial Port

2. Hardwired Communication between PC and Octobot

LEDs

Handy Board

LCD

Functions:(i) Host PC control of Handy Board LEDs, LCD and motors.(ii). Communicate handy Board sensor data to host PC.

Motor 1

Motor 2

Sensor 1

Sensor 2

Sensor 3

Sensor 4

Octobot Robot

Radiometrix RPC

Radiometrix RPC

LEDs

Handy Board

LCD

3. Wireless communication between PC and Octobot

Functions:(i) Host PC control of Handy Board LEDs, LCD and motors.(ii) Communicate Handy Board sensor data to host PC.

4. Wireless communication between PowerPC (on Xilinx VII Pro) and PC host

Radiometrix RPC

Radiometrix RPC

Functions:(i) Host PC control of XUP board LEDs and LCD.(ii) XUP switch control of Host.

Powerpc

Push Button Switchs

LEDs

DIP Switchs

Virtex II Pro

Motor 1

Motor 2

Sensor 1

Sensor 2 Sensor 3

Sensor 4

Octobot Robot

Sensors – SHARP GP2D120 IR sensor

Wireless device – Radiometrix FRPC2-433-160

5. Hardwired Communication between PowerPC (on Xilinx VII Pro) and Octobot

Functions:(i) Powerpc control of Handy Board LEDs, LCD and motors(ii) Communicate Handy Board sensor data to powerpc.

LEDs

Handy Board

LCD

Powerpc

Push Button Switchs

LEDs

DIP Switchs

Virtex II Pro

Motor 1

Motor 2

Sensor 1

Sensor 2 Sensor 3

Sensor 4

Octobot Robot

Sensors – SHARP GP2D120 IR sensor

Wireless device – Radiometrix FRPC2-433-160

6. Wireless Communication between PowerPC (on Xilinx VII Pro) and Octobot

Radiometrix RPC

Radiometrix RPC

LEDs

Handy Board

LCD

Functions:(i) Powerpc control Handy Board LEDs, LCD and motors.(ii) Communicate handy Board sensor data to powerpc.(iii) Implement a maze strategy.

Powerpc

Push Button Switchs

LEDs

DIP Switchs

Virtex II Pro

The Handy Board

• The handy board is used to interface with the sensors and motors of the robot

• The core of the handy board is a motorola 68HC11 micro processor.

• The analog outputs of the sensors are converted to a 8 bit digital word by the micro-processor. This 8-bit value is then sent to the FPGA via the wireless link.

The Handy Board

Wireless Link

• The wireless link is implemented using a radiometrix RPC (Radio Packet control).

• The RPC module provides all the RF circuits required to inter-connect an number of micro-controllers in a radio network.

Radiometrix RPC

• A data packet of 1 to 27 bytes downloaded by a Host micro-controller into the RPC's packet buffer is transmitted by the RPC's transceiver and will "appear" in the receive buffer of all the RPC's within radio range.

• A data packet received by the RPC's transceiver is decoded, stored in a packet buffer and the Host micro-controller signalled that a valid packet is waiting to be uploaded.

Pin Functions

The Radiometrix RPC has 8 pins, 4 data lines and 4 control lines:

• D0 – D3: 4 bi-directional data lines

• TXR: TX request. Data transfer request from HOST to FRPC2

• TXA: TX Accept. Data accept handshake back to HOST

• RXR: RX Request. Data transfer request from FRPC2 to HOST

• RXA: RX Accept. Data accept handshake back to FRPC2