Critical Design Review

2/26/2009Jay Brasch Daniel KopeloveKirk Nichols Katrina Bossert

Project Overview

• Create a sensing vehicle with the following functionality– Natural gas sensor– Geiger counter– Streaming video

• Control various aspects of the vehicle– Orientation and position of vehicle– Orientation and position of camera (two-axis

control)

Kirk Nichols

Current Project Status• SCAB I rev c– New Parts

• ENC28J60• AtTiny24• ATF16LV8C

• SCAB II rev a– New additions

• LPC 2377• Motor Relays • Ethernet PHY Module

• Peripherals– Geiger counter constructed, awaiting radioactive source

for sufficient testing

Kirk Nichols

System Diagram

NXP 2214/2377

ADC(2)

Gas Sensor

(Range Sensors)

Pulse(2)

Geiger(Velocity)

(Compass)I2C(3)

Sensing Ports

PHY/MAC Layer

DC Motor

DC Motor

Servo(3)

UART(5)+

ATF750 CPLD

System Information

Vehicle Control

Battery Level

Battery Level

Debug Port

Debug Port

Ethernet

Base Station

LaptopLaptop LabVIEWLabVIEW

Vuzix HUDVuzix HUD

USB Joystick

(Peripherals)

AtTiny24AtTiny24 ATF16LV8CATF16LV8C

Kirk Nichols

SCAB I - AtTiny24

• Peripheral Microcontroller– 10 MHz– SPI interface– Offload the following peripheral interfaces from

the LPC 2214/2377• 8 ADCs• 12 External interrupt pins

Kirk Nichols

SCAB I - ATF16LV8C

• Multiplex serial communication such that all serial communication can be controlled with one UART port on LPC 2214/2377.

• Programmable with WinCUPL• 3.3V Source

Kirk Nichols

SCAB II - New Microcontroller – LPC2377

Advantages over the LPC2214 Microcontroller

• Ethernet MAC with associated DMA Controller

Access to PHY chip via MII

Put Ethernet work into hardware instead of software

• Real-Time Clock

•RTOS software available

Disadvantages

•Only 3.3V source needed instead of 3.3/1.8V, therefore consumes more power

•Need to Port Code

Kirk Nichols

SCAB II - KS8721BL

• I/F to 802.3 compliant MAC system on the LPC2377

• Media Independent Interface Management (MIIM)

• Internal 2.5V regulator• 50MHz VCO• Connects to RJ-45 with Magnetics• LQFP-48

Daniel Kopelove

SCAB II - KS8721BL

• 100Base-TX/FX – Increased regularity thanks to fiber

• Link status interruptsSoftware:• Olimex Board – RTOS+UIP

Daniel Kopelove

KS8721BLMDIO1

MDC2

RXD3/PHYAD13

RXD2/PHYAD24

RXD1/PHYAD35

RXD0/PHYAD46

VDDIO7

GND8

RXDV/PCS_LPBK9

RXC10

RXER/ISO11

GND12

VDDC13

TXER14

TXC/REF_CLK15

TXEN16

TXD017

TXD118

TXD219

TXD320

CO/RMII21

CRS/RMII_BTB22

GND23

VDDIO24 INT/PHYAD0 25LED0/TEST 26LED1/SPD100 27LED2/DUPLEX 28LED3/NWAYEN 29PD 30VDDRX 31RX- 32RX+ 33FXSD/FXEN 34GND 35GND 36REXT 37VDDRCV 38GND 39TX- 40TX+ 41VDDTX 42GND 43GND 44X0 45X1 46VDDPLL 47RST 48

KS8721BLE1

KS8721bl

LED100LEDACT

TX+

RX+

TX-

RX-

E_MDIOE_MDC

E_RXD1E_RXD0

E_RX_ER

E_REF_CLKE_TX_ENE_TXD0E_TXD1

E_CRS

3v3

GNDGND

GND

100nF

C111

GND

100nF

C112

GND

3v3

10kR107

3v3

100nF

C113

NetLabel317

GND

3v3

NC100nF

C114

GND

3v3 3v3

GND

100nF

C115

3v3

10kR108

3v3

10kR109

3v3

PD

PD

PHY_INT

3v3

10kR110

E_X1

E_X1

4.99kR111

1.5kR112

GND

REXT

REXT

RST

TRI1

GND2

Output 3

VDD 4

CD1

VCO

E_REF_CLK

GND

3v3

100nF

C116

VDDTX local bypass

Daniel Kopelove

Communication Protocol

• Command set (from LabVIEW to scab)• Data packets (from SCAB to LabVIEW)• LabVIEW is an intelligent controller (sends low

level commands to SCAB)• Data packets are static size

Daniel Kopelove

Command Packet StructureField (offset) Timestamp

(0x0)Sequence Num (0x3)

Opcode (0x7) Optional Raw Data (0x9)

Format U32 U32 U16 U64

Timestamp – excessively late packet arrivalsSequence num – used for statisticsOpcode – one of the predefined commandsOptional Raw Data – A command may have some extra data, the format of this data depends upon which opcode accompanies it, Null padded, even word aligned

Daniel Kopelove

Command Set

• Current implemented commandsCommand Code

Set speed pulse width 0x0010

Set vehicle heading servo pulse width 0x0011

Set pan servo pulse width 0x0012

Set tilt servo pulse width 0x0013

Send data 0x0020

Set periodic data transmission interval 0x0021

Restart system 0x0030

Reset DC motor controller 0x0031

Self Destruct 0x0BAD

Daniel Kopelove

Data Packet StructureField (offset) Timestamp

(0x00)Sequence Num (0x03)

Valid (0x07) Geiger counts last sec (0x0E)

Format U32 U32 U64 U16

Field (offset)

Geiger counts last 5 sec (0x11)

Geiger counts Last X sec (0x13)

Geiger counts last Y sec (0x15)

Speed pulse last W sec (0x17)

Format U16 U16 U16 U16

Field (offset)

Speed pulseLast X sec (0x19)

Speed pulse last Y sec (0x1B)

Speed pulse last Z sec (0x1D)

Gas LEL (0x1F)

Format U16 U16 U16 U16

Daniel Kopelove

Data Packet Structure (cont)Field (offset) A/D 2 (0x21) Compass

(0x23)I2C 1 (0x27) I2C 2 (0x2B)

Format U16 U32 U32 U32

Field (offset) Battery stack V 1 (0x2F)

Battery stack V 2 (0x31)

Servo 1 pulse width (0x33)

Servo 2 pulse width (0x35)

Format U16 U16 U16 U16

Field (offset) Servo 3 pulse width (0x37)

H&S Data (0x39)

Speed pulse width (0x3D)

Format U16 U32 U16

Daniel Kopelove

LabVIEW User Interface

Katrina Bossert

LabVIEW: Successes and Problems

• Successful– Reasonable user interface– Web browser and successful IP address

connection

• Problems– LabVIEW USB Driver– Limitations in programming (e.g. you must

request a specific size of data from a TCP/IP connection)

Katrina Bossert

Current User Interface

LabVIEW

USB Joystick& LabVIEW Driver

Video Streaming

TCP IP and Communication

protocol

Keyboard Control

Goggles(incorporate

C++ code)

Serial Communication

Katrina Bossert

FreeRTOS

• “Don’t do it”– Threading never as simple as it seems

• Advantages– Manages system timers and interrupts– Convenient scheduling of recurring tasks

• Our implementation– Latencies as high as 100 ms acceptable– Short, simple tasks

Jay Brasch

FreeRTOS Pseudocodevoid ethernetController( void *pvParameters ){

DataType Data1, Data2

while( true) {

vTaskDelayUntil( &xLastWakeTime, CYCLE_RATE_MS ) // Request data from the sensors.

if(checkEthernetQueue(&Data1)if (Data.HighPriority)

processCriticalTask(Data1)else

processNormalTask(Data1)}

}}

Jay Brasch

Power Design

Two battery sources for maximum isolation

Jay Brasch

12 V (26 W) Consumption (W) 7.6V (21 W) Consumption(W)

SCAB 4 Motor 20

Ethernet Controller 3 Ethernet Camera 6

Router 6 Servos 2

Geiger Counter 2

Total 15 Total 26

*35W motor battery readily available

FAIL! Handling

• Goal: Handle unexpected conditions gracefully– “Heartbeat” packet sent periodically– Battery state sensing– Relays• Reset motor controller• Reset router manually or 90 dB buzzer

– Lost communication procedures• Wait and attempt reconnect• Move 5s opposite most recent heading• Execute Start of Day (SOD) task

Jay Brasch

RTOS Scheduling (periodic)

Jay Brasch

Task Time 1 2 3 4 5 6 7 8 9 10 11

Poll Tiny 1 x

Poll Batt 1 x

Poll Link 1 x

Poll Periph 1 x

Poll Command Queue 1 x

Poll Speed 1 x

Poll Gas 1 x

Heartbeat 1 x

Comm. INT 3 x x x

RTOS Scheduling (aperiodic)

Jay Brasch

Task Time

Request from Tiny 1

Open/Close relays 1

Actuate Servos 1

Change motor speed 1

Send Data 3

Milestones• Milestone 1– SCAB installed on vehicle

• Controlling motors• Controlling camera

– Embed video stream in LabVIEW– LabVIEW controls vehicle via RS232

• Milestone 2– SCAB acts as network host

• Transmits telemetry data to LabVIEW interface– LabVIEW acts as network host

• Transmits control commands to SCAB– System can run 30 minutes from battery

Katrina Bossert

Questions

HUD

ResponsibilitiesKirk

Katrina

Jay

Dan

Ethernet Communication

Router

SCABVehicle

LabVIEW

Katrina Bossert

KS8721BL

180R101

180R102

LEDACTLED100

TX+ TX-

RX+ RX-

49.9R103

49.9R104

49.9R105

49.9R106

100nF

C109

L1

3v3

100nF

C110

GND

TPOUT- 2

rcon6

TPOUT+1

TPIN+7

LED1+9

LED2+11

TPIN-8

LED1-10

LED2-12

tcon3

RJ45 w/Mag

U22

magjack

3v3

Kirk Nichols

LPC 2377

Kirk Nichols

ATF16LV8C

Kirk Nichols

Kirk Nichols

KS8721BL

• u08 pkt1[] = {0x00,• 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x00, 0x16,• 0xb6, 0x98, 0x95, 0x3f, 0x08, 0x06, 0x00, 0x01,• 0x08, 0x00, 0x06, 0x04, 0x00, 0x01, 0x00, 0x16,• 0xb6, 0x98, 0x95, 0x1f, 0x0a, 0x00, 0x01, 0x02,• 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0a, 0x00,• 0x01, 0x14 };

• IO3DIR |= 0x00000002;• IO3SET = 0x00000002;

• initMAC();

• write_ptr = ReadETHReg(EWRPTL);• write_ptr |= (ReadETHReg(EWRPTH) << 8);• WriteMacBuffer(pkt1, 51);• write_ptr = ReadETHReg(EWRPTL);• write_ptr |= (ReadETHReg(EWRPTH) << 8);• WriteCtrReg(ETXNDL, write_ptr);• WriteCtrReg(ETXNDH, (write_ptr >> 8));• SetBitField(ECON1,ECON1_TXRTS);

Kirk Nichols

Kirk Nichols