Team Chopper Distributed Communication Nodes for Autonomous Helicopters Shirley Choi Bejan Hafezzadeh Joseph Kaiser Sean Norwood Itay Tenne

Introduction Overview Topological Avionics Diagram CAIN PCB (Can Avionics Interface Node) –Block Diagram (all ICs in relative location) –Schematic –Layout –Pictures JOANN protocol –Key features & Terminology –Abstract CAIN Block Diagram & Unit Example –Comprehensive Example Part List Division of Labor Schedule Subterranean Mapping Using Wire Suspended by Two Autonomous Co-operative Helicopters Normal Mode Inverted Mode DeSalvo Tandem

Topological Diagram Bluetooth Host PC for test, debug, and configuration ServosRC receiver RC Transmitter PWM signals RS232 Servo battery On board Radio RS644 USB Error Correcting GPS Power Board Power Generator All Boards Flight Computer Interface Board IMU Interface Board GPS Interface Board Pressure Sensors Interface Board Magnetometer Interface Board INS Satellites RS232 Interface Board Interface Board Ground Radio To GPS Interface Board Bluetooth Module RS232 USB CAN Multi-Drop Bus Servo Isolation

CAIN PCB Block Layout ISP TWI/SPIADC JTAG addr Addr/data Atmel AT90CAN128 CAN transceiver / CAN bus LEDs Jumpers/Selectors PWM (6 channels) RS232-1 RS232-0RS644 NV RAM EEPPOM CAN transceiver / CAN bus

CAIN Schematic

CAIN 6-Layer PCB TOPPWRSIG1 SIG2GNDBOTTOM

CAIN Revision 1 Pictures TOP PopulatedBottom Populated Status Processor & All peripherals functional I2C EEPROM untested NVRAM untested

Power Distribution Board Takes AC from the onboard Brushless Alternator Converts to DC Regulates the DC it to 5.4Volts D.C. Converts the 5.4Volts D.C. to many other voltages (+5V,+3.3V,±8.5V) Will be implemented on a PCB

Power Distribution Board To be implemented on a Printed Circuit Board Will use on chip switching converters for high efficiency. Will use Surface mount chips for low noise and ruggedness.

Power Supply Board Alternator Volts Depending on Motor Speed Three phase Rectifier Outputs Volts D.C. Regulated DC-DC switching converter Converts to 5.4 Volts D.C. +5 Volts Switching Converter +3.3 Volts Switching Converter +8.5 Volts Switching Converter -8.5 Volts Switching Converter

JOANN Protocol Key Features Generic and Powerful Easy to use Conceptually similar to a directed graph FIFO buffers are pervasively used as sockets Sockets and Channels are established during initialization. Kernel runs in background and routes source to destination. Configurable Real-Time Transit Delays “Jolly Old Avionics Node Networking” (actually named in retribution to JOANN for the shopping cart)

Terminology “socket”: a FIFO buffer which is used as a global source or sink, analogous to vertices in a directed graph. “channel”: a custom struct which holds all information about the channel between two sockets, including the id_path, transit_delay, source and sink pointer, etc., analogous to an edge. “id_path”: FIFO buffer of multiple IDs linking nodes and sockets. “port”: a FIFO buffer for low level on- chip external interface (UART, I2C, CAN,PWM_IN, PWM_OUT…) “node”: one of the physical CAIN PCBs “FIFO buffer”: First In First Out buffer that passes data along the channel Source Port Sink Port Source Socket Sink Socket Channel

Simple Example Port_A Device_m Port_B Device_n s_sock_1d_sock_1s_sock_2 d_sock_2d_sock_3s_sock_3 get_dev_m_data() or ISR() dev_m_parser() router() process_1() send_dev_m_data() or ISR() router() dev_n_dispatcher() process_2() Select Devices in config.h UART1_DEVICE = IMU UART1_DEVICE = GPS UART1_DEVICE = PRESSURE … PWM_CH_1_DEVICE = SERVO I2C_DEVICE = EEPROM … On-Board Ports UART0 (RS232 or TTL) UART1 (RS232,RS644 or TTL) CAN SPI I2C GP I/O & ADC PWM_CH_m OUT PWM_CH_n IN

servo_ch1 rcvr_ch1 servo_ch2 servo_ch3 rcvr_ch2 rcvr_ch3 servo_ch1 rcvr_ch1 servo_ch2 servo_ch3 rcvr_ch2 rcvr_ch3 BLUETOOTH GPSELAN 5P IMU Less simple example

Mainloop() { router() //Background Kernel #if UART0_DEVICE == IMU imu_service(); #endif //… same for all gps_service(); elan_service(); rcvr_service(); servo_service(); bluetooth_service(); process1(); process2(); process3(); } Init_ports(); #if UART0_DEVICE == IMU Init_buffer(A,SIZE_A); XRAM_PTR += SIZE_A; //… same for all #endif //attach UART_PORT to IMU SOCKET Init_buffer(B, SIZE_B); Init_buffer(C, SIZE_C); //Channel ID_paths used to connect sockets //could make as many as you want Init_buffer(ID_path, SIZE_PATH); Link_to_ID_path(B); Link_to_ID_path(C); Link_to_ID_path(SERVO1); //last one on path is object ID //Create channel object linking A to SERVO1 //Locally, only a single edge //Globally, a path defined here is propagated. Create_new_channel(A,ID_path); Code Example

Controller Area Network (CAN) We will use CAN to transmit data between our avionics equipment CAN is a multicast serial bus standard that allows for high data transfer rates It allows for priority-based bus arbitration, ideal for our system

Standard CAN Data Frame The 11 bit identifier field allows for bus arbitration 4 bit DLC field declares the length of the data packet in the following field The integrity of the data is protected by a checksum (CRC)

CAN Controller CAN controller on the AT90CAN128 Microcontroller

Memory mapping on CAIN board

RC Demodulation RC Receiver PWM Demodulator CAN Parser / Dispatcher PWM Port To servos

Servos Motor with an onboard controller Gets position Signals and moves to that position Receives commands via PWM 5volt supply needed

GPS NMEA standard –GPGGA sentence identifier RS232 interface ASCII messaging format NMEA: Latitude longitude altitude

GPS Tested the GPS with GPSolution

Flight Box Isolate vibration from the helicopter A damper-spring system Provide shielding for the power board Designed with Solidworks, analyzed by Ansys Carbon fiber and aluminum Will be machined and assemble in ITLL

Example: GPS board mounting

Part List ModuleCostSub Total Custom Cain PCBs Manufacturing150 Assembly100 Components CAIN PCB for: IMU Node300 GPS Node300 Servo Node300 Flight Computer Node300 Bluetooth Node COTS Bluetooth Module Donated Custom Power PCB Manufacturing100 Assembly100 Components Custom Avionics Flight Box 200 STk500/501 development board 200 JTAG In Circuit Emulator Donated Miscellaneous Small Parts 170 Total: $2320 Funded by Prof. Meyer and UROP

Part List Partsquantity Chopper1 Digital Servos1 586-Engine-P1 GPS1 STK500 development board 2 RC receiver1 Shopping Cart1 12V battery2 Provided by Prof. Meyer:

Division of Labor Bejan –I2C on chip communication –Node testing routines Itay –RC demodulation –JOANN development Joe –Power PCB –Servo driver Sean –JOANN development –CAIN PCB revision 2 Shirley –Flight Box –GPS All –Testing and Debugging

Updated Gantt Chart

Goals Toward Milestones Milestone I –Completion of the power board PCB –Completion of the fabrication of the flight box –Completion of the Servo node –Completion of JOANN research development Milestone II –Fully tested JOANN –System completely interfacing thought CAN bus –Shopping Cart testing

Goals Toward Expo Completion of CAIN PCB revision 2 System Identification Hopefully Hovering!

Questions?