Electronic Guidance Device(EGD)PurposeObjectivesProject Block DiagramOverall SchematicSoftware/Hardware InteractionVisual InitializerVisual Initializer (cont.)Software ProcessesI2C – Writing to SlaveI2C – Reading from SlaveTransmitter CircuitI2C Transmit WaveformCode outline for voice chipVoice Chip SchematicVoice chip circuitTest ResultsHardware and device listSchedule and the Division of laborPlanned DeliveriesContingency PlanComments/Questions?Electronic Guidance Electronic Guidance Device(EGD)Device(EGD)Group MembersStephen HarrisAbdul-Karim Al-ShanfariBradley SmethieRobert BornhijmPurposeTo design a navigational aid for the blind and vision impaired.ObjectivesTo integrate with existing guidance cane.To provide information through audible feedback to user about fore lying object or sharp elevation changes.Geographical direction is to be provided at the user’s discretion.Project Block DiagramOverall SchematicSoftware/Hardware InteractionPicstart Plus Interfaces PIC with ComputerC-compilerVisual InitializerVisual Initializer (cont.)Software ProcessesStructure of:I2C transmit (writing to SRF08)I2C receive (reading from SRF08)Voice chip softwareI2C – Writing to SlaveSend Start ConditionSend Address of SRF08 (R/W-bit=0) Send specific internal address of command registerSend data byte (to specify ranging mode and units of result)Send Stop ConditionI2C – Reading from SlaveSend Start ConditionSend Address of SRF08 (R/W bit = 0)Send specific internal address of command registerSend second Start ConditionSend Address of SRF08 (R/W bit = 1)Read the data byte off the busSend Stop ConditionTransmitter CircuitI2C Transmit WaveformCode outline for voice chip Using the M0 and the M6 mode on the voice chip we will be able to fast forward to the correct address for the message that we are trying to get to.The code will generate the timing so it can appropriately address the required sound byte.The code will also make sure it is in the right addressing code.Voice Chip SchematicVoice chip circuitTest ResultsSo far we have completed the following:- Communication with PIC18F452- Simple test program – Blinking LEDs- Recording/Playing Voice Chip- Writing to the SRF08 module- DocumentationHardware and device listMicrocontroller (18F452)Speech chip (ISD2560)Electronic Compass (Vector 2x Compass by Precision Navigation)Ultrasonic Devices (SRF08 Ranger by Devantech)Battery (5V rechargeable)Headphones (any 16 Ohm impedance headphone will do)Volume control ( potentiometer)Schedule and the Division of laborPlanned DeliveriesMilestone 1: Having the rangefinder and the voice chip communicating using the PICMilestone 2: Having the overall design working and the PCB Expo-day: Demonstrating the device using the PCBContingency PlanMost likely will switch to a I2C based compass available from Devantech.Current Compass requires SPI, SPI pins on PIC already in use by I2C. We could work around this, however an I2C compass would be much simpler
View Full Document
Unlocking...