Built-In Test Software for Deformable Mirror High Voltage DriversBuilt-In Test Software for Deformable Mirror High Voltage Drivers

Jianwei ZhouJianwei Zhou

Home Institution: University of Hawaii at ManoaHome Institution: University of Hawaii at Manoa

CfAO Akaimai Internship 2008CfAO Akaimai Internship 2008

Subaru TelescopeSubaru Telescope

Mentor: Stephen ColleyMentor: Stephen Colley

Funding provided by the Center for Adaptive Optics through its NatioFunding provided by the Center for Adaptive Optics through its National Science Foundation Science and Technology Center grant (#AST-98nal Science Foundation Science and Technology Center grant (#AST-98

7683)7683)

Today’s PresentationToday’s Presentation

BackgroundBackground Importance of Build-In Test softwareImportance of Build-In Test software Design ProcessDesign Process ConclusionConclusion AcknowledgementAcknowledgement

AcronymsAcronyms A/D – Analog to DigitalA/D – Analog to Digital D/A – Digital to AnalogD/A – Digital to Analog BIT- Built-In TestBIT- Built-In Test DM- Deformable MirrorDM- Deformable Mirror HV – High VoltageHV – High Voltage ICD – In-Circuit DebuggerICD – In-Circuit Debugger LGSAO – Laser Guide Star Adaptive-Optics LGSAO – Laser Guide Star Adaptive-Optics MUX – MultiplexerMUX – Multiplexer

Project OverviewProject Overview

Design Design BBuiltuilt-In-In TTestest (BIT) (BIT) software for software for deformable mirror high voltage driver in the deformable mirror high voltage driver in the Subaru LGSAO system.Subaru LGSAO system.

Measurements performed by BIT circuitryMeasurements performed by BIT circuitry Input VoltagesInput Voltages Output VoltagesOutput Voltages Power Supply VoltagesPower Supply Voltages Board Temperature Board Temperature

Deformable Mirror (DM)Deformable Mirror (DM)

DM is used with wavefront sensor to provided optical control and correction.DM is used with wavefront sensor to provided optical control and correction. The DM is divided into 188 segments with separate control voltage to each segmentThe DM is divided into 188 segments with separate control voltage to each segment DM operates with maximum voltages of DM operates with maximum voltages of ++400V, and HV amplifiers with gain of 40 are u400V, and HV amplifiers with gain of 40 are u

sed to amplify input voltages of sed to amplify input voltages of ++ 10v to 10v to ++400v.400v.

HV Driver SubsystemHV Driver Subsystem

The HV driver subsystem in the Subaru LGSAO system The HV driver subsystem in the Subaru LGSAO system consist of 10 HV Amplifier boardsconsist of 10 HV Amplifier boards

High High VoltageVoltage Amplifier Board Amplifier Board

Real-TimeControl

Computer

D/A Converter

Board

HVAmplifier

Boardw/BIT

DM

188

+ 10v

188

+ 400 vDigital

Data

Importance of Built-In Test SoftwareImportance of Built-In Test Software

Built-In Test CircuitBuilt-In Test CircuitMain componentsMain components: :

Analog Multiplexer (Mux)Analog Multiplexer (Mux)

Analog-To-Digital Converter Analog-To-Digital Converter

Microcontroller (PIC 16F877)Microcontroller (PIC 16F877)

Temperature SensorTemperature Sensor

Mux A/D Converter

Microcontroller

Temperature Sensor

Host Computer

BIT Circuit

Built-In Test SoftwareBuilt-In Test Software Program Language use: CProgram Language use: C

Step 1: Program in C Step 1: Program in C

Step 2: Compile to Assembly language by PICC STD.Step 2: Compile to Assembly language by PICC STD.

Pros and consPros and cons C is easier and much shorter than assembly languageC is easier and much shorter than assembly language Programming requires the knowledge of microcontrollerProgramming requires the knowledge of microcontroller

In-Circuit DebuggerIn-Circuit Debugger

Real-time debugger and programmerReal-time debugger and programmer

MPLAB IDEMPLAB IDE

Memory ConstrainMemory Constraintsts of of MicrocontrollerMicrocontroller

Programs must fit in the available on-chip program Programs must fit in the available on-chip program memory ( very small compare to computer)memory ( very small compare to computer)

Must optimize the code to reduce the memoryMust optimize the code to reduce the memory

ConclusionConclusion Tested the BIT circuit Tested the BIT circuit

1 bad A/D converter is found in one board1 bad A/D converter is found in one board

Fabrication error of temperature sensorFabrication error of temperature sensor

BIT software successfully measures the input BIT software successfully measures the input voltages, output voltages, and power supply vovoltages, output voltages, and power supply voltages on a HV amplifier boardltages on a HV amplifier board

Work To Be CompletedWork To Be Completed

Communication between the BIT circuit and Communication between the BIT circuit and host computerhost computer

Run the BIT software in the whole LGSAO Run the BIT software in the whole LGSAO systemsystem

Personal ThoughtPersonal Thought

A valuable opportunity to learn about circuit dA valuable opportunity to learn about circuit designesign

Application of the knowledge learnt in school Application of the knowledge learnt in school to real life practice to real life practice

Increased research abilityIncreased research ability Increased ConfidenceIncreased Confidence

AcknowledgementsAcknowledgements

Stephen Colley, MentorStephen Colley, Mentor Akamai Internship staffAkamai Internship staff

Sarah Anderson, Hawaii Island Internship CoordinatorSarah Anderson, Hawaii Island Internship Coordinator

Lynne Raschke, Science Communication Lead InstructorLynne Raschke, Science Communication Lead Instructor

Scott Seagroves, Science Communication Co-instructorScott Seagroves, Science Communication Co-instructor

Lisa Hunter, Akamai InterLisa Hunter, Akamai Internnship Directorship Director