Liter Liquid Tending Robot Julie Lam Kevin Chang Jason Smith Andrew Jenkins

Objectives  Move using tracks and motor  Receive order by using Keypad and LCD  Delivering an assortment of drink through controlled valves  Read customer information (tab, name, preferences) through magstripe reader.  Follow route using sensors.  Pre-recorded voice prompts. Core Goals Extensions

Block Diagram Microcontroller SRAM ROM FPGA Power Supply 5V LCD Keypad Motors Valve Solenoids Registers Interrupts Card Reader Path Sensor A/D 110VAC Microcontroller SRAM ROM FPGA Power Supply 12V_UNREG 5V -15V LCD Keypad Motors Washer Pumps Registers Interrupts Card Reader Path Sensor A/D 110VAC 15V

Status  68HC11 is up, running uC code from ROM, read/writing to RAM, communicating via RS-232 to host PC.  Interrupt-driven communication.  Unregulated power supply complete, provides plenty of power for washer pumps and motors (>2A).  Tested with pumps – works.  Motor base turns, moves, varies speed; with bench setup (not a Puerile design).

FPGA- XCS10 Kevin Chang

FPGA Overview  XCS10 FPGA device  Interface between microcontroller and ‘dumb’ peripheral devices.  Chip selection based on address bus  Registers for valve controls and motor controls.  Interrupt detector and interrupt controller.

Microcontroller-HC11 Jason Smith

Hello World Test in C

Interrupt Test

LCD MICROCONTROLLER  Store ROM information into registers  Selects the LCD  Outputs the ROM information FPGA  Tells ROM to place information on the bus  Selects LCD to receive information from the data bus

Pumps MICROCONTROLLER  Processes pump selection and duration  Outputs above information onto the address and data buses  Receives interrupt FPGA  Selects appropriate pump and outputs power to transistor  Uses decrementer to hold selected pump for the duration  Send interrupt when finished

Motor MICROCONTROLLER  Outputs direction, speed, and stop command FPGA  Controls the motor inputs  Uses direction input to output to motor  Stores speed input to the duty cycle register  Uses stop command to turn off motors

Light Sensors MICROCONTROLLER  Performs ADC of light sensor photo transistors  Processes light sensor data for path correction or stop command  Outputs appropriate data to FPGA FPGA  Selects light sensors

Card reader MICROCONTROLLER  Receives interrupt  Reads from FPGA interrupt register  Reads card information and location from card data shift register FPGA  Generates XIRQ interrupt when card leaves card reader  Stores serial card data into shift register as card is swiped

RS-232  Receives and sends debugging commands to the microcontroller.

High level microcontroller processes  Priority queuing  Priority interrupt control  Processing orders  Processing path following algorithm  Processing card reader information

Interface Circuits  Pump Control Circuit  Motor Control Circuit  Line Follower Sensors  Keypad Interface  LCD Interface

Motor Control Circuit  Uses L293D Motor Driver  DC Gear Motors  Input 2x PWM signal (square wave, ~1kHz, duty cycle->speed).  Input 2x direction signal.  Provide motor power (12VDC, 400mA).  FPGA provides PWM, direction.

Motor Control Circuit

Pump Control Circuit  TTL compatible (FPGA).  P-channel Power MOSFET dissipates 190mW.  6N138 Darlington Optoisolator (CTR 2000%) Pump Current Monitor 0.05 Ohm Current-Sense resistor, common for all high-power (> 1W) applications. LM6462 Rail-to-rail OpAmp->Current Reference 6N135 Analog Optoisolator (CTR ~20%)

Pump Control Circuit

Line Follower  LED current adjustable, >= 1mA  LED on/off controlled by FET, TTL/CMOS compatible.  Phototransistor senses light level, believe ~1mA peak current.  Will add OpAmp to expand signal if needed.  Uses 4 channels of CD4051 Analog Multiplexer, select controlled by FPGA.

Line Follower

Magnetic Card Reader  3 Mag Card Readers  Outputs “Card Inserted” signal – used to enable the FPGA shift register  Outputs “Data Clock” – used to clock the data into the FPGA shift register  Outputs “Data” – the data.

Magnetic Card Reader

Keypad  MM74C922 decodes Row/Column Keypad into 4 bits data.  Double buffer register.  Debounce capacitor.  Data available signal.

Keypad

LCD Interface  CrystalFontz CFAH-2004A-RMC-JP  20x4 Character Display, parallel interface, red backlight

LCD Interface

Power Supply Julie Lam

Power Supply Tech  From ~110VAC Wall outlet, fused.  One transformer from ~110VAC to 12VDC  Using a bridge rectifier, diode and large cap for the circuit.  Using a pre-assembled 110VA to 1.8A power supply for Logic devices (with +/- 15 for Analog).  Using an unregulated power supply for peripherals such as motor and pumps (~12VDC, > 2A).

Milestone 1  1st PCB rev completed and ordered  Complete and working setup for motor, pumps and other hardware  Communication between microcontroller and FPGA  Initial integration of motor, pumps and software controls

Milestone 2  All software coded  Completed integration of design  Begin testing full system

Timeline

Parts and Costs

Show and Tell

Division of Labor  Kevin Chang and Julie Lam  FPGA pump control, motor control interfacing and Programming  Jason Smith and Andrew Jenkins  Microcontroller and motor interfacing and Programming