Washing Machine SolutionsAffordable Intelligent Motion
SenseTile Hardware Design Review 1
CASL, UCD, 12 December 2008
1Confidential mSemicon & UCD19/04/23
Agenda
Current status of design work Description of design Extra features Dimensions Schedule
2Confidential mSemicon & UCD19/04/23
Current Status of Design Work
Schematic has been completed about 99% All on-board electronic components selected
Only issue remaining relates to selection of connectors Some other minor issues Some feedback required on mechanical issues
Following today’s review, layout is expected to begin immediately
3Confidential mSemicon & UCD19/04/23
General Description of Design
The schematic is divided into eight separate sheets describing: CODEC / ADC circuit FPGA circuit Audio and ultrasonic inputs Audio input circuitry (Input 1) General input circuitry (Input 2) Microcontroller circuitry Output circuitry Power supply circuitry (Prior USB circuitry, to be removed) New USB circuitry
4Confidential mSemicon & UCD19/04/23
CODEC / ADC
Design based on two devices:
ADC for simultaneous sampling (for non-audio applications) ADS1174/8 For slowly changing signals: DC to 4kHz sampling Four channel
CODEC AD1937 Very high performance: high speed Built-in audio filters Extremely low noise
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FPGA
Design based on Xilinx XC3S250 (Spartan)
General purpose FPGA Configuration by:
JTAG (during development) SPI (direct, during test and development); SPI can be directly updated by USB (i.e. not through the microcontroller)
on deployment
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Audio Input Circuitry – Input 1
Catering for audio range (2) and ultrasonic range (2)
Number of total usable inputs depends on sample rate Extremely low noise amplifiers
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General Input Circuitry - Input 2
Catering for general inputs from sensors and switches
Four analogue inputs
Eight digital I/O User configurable via microcontroller
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Microcontroller Circuit
Based on STM32F103V9 Cortex device from ST
Latest generation Cortex ARM processor Built in RAM/Flash Multifunction I/O JTAG programmable in-circuit debugger
RS 232 debug port, allowing external programming of micro flash GSM port
9Confidential mSemicon & UCD19/04/23
Output Circuitry
Drivers for speakers Audio Ultrasonic
On board relays (2) IR LED drivers (shown on FPGA sheet) IR detection to be added
10Confidential mSemicon & UCD19/04/23
Power Supply
Works on 12-30Vdc in Generated on board: 1.2V, 2.5V (linear), 3.3V x 2, 5V, -11V, +11V Point of load power supply design
FPGA powered separately Analogue circuitry powered separately Microcontroller can operate on its own
Current sensor on board, monitoring total current consumption Information processed by microcontroller
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(Prior USB Design)
Until last few weeks, USB was run on a MCS7840 Four channel UART to USB device Satisfied requirements, but
Heavy load on FPGA Mandated FPGA programming indirectly
A new device is becoming available now, and will be used instead
12Confidential mSemicon & UCD19/04/23
New USB Ciruitry
FTDI USB-high speed data port A new electronic device is being sampled at the moment, and will
enter production “in March 2009” which, on board, would allow: Direct programming of the SPI Direct access to generalised I/O CPU high-speed parallel bus interface (asynchronous) Four fold (+) increase in performance
Host can talk directly to the FPGA via file transfer
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Extra Features
Adding a port for a display: Considering making provision for LCD display This enables easier autonomous use of device Display itself not installed on boards
Other features being considered and, if possible, included
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Current Draft Connector Requirements
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Connector Type of Socket
Power StandardUSB (1) USB-B Acoustic microphone (4) [high perf.]
3.5mm jack
Acoustic speaker (1) 3.5mm jack
Ultrasonic speaker (1) 3.5mm jack
Ultrasonic microphones (4) 3.5mm jack
Digital I/O IDC 0.1”Relay contacts IDC 0.1”Analog expansion slot IDC 0.1”
External DC power supply 3.1mm power
Connectors – Sensor Inputs The selection of connectors influences overall board size
Try to be as compact as possible Another requirement is that special mating connectors should not be
necessary – for R&D work A suitable connector style is the DIN 45326
Can take up to 8 wires in one unit Suitable for sensor inputs Rotates and locks into position Wires can be soldered onto mating part
This type proposed for simultaneous inputs
16Confidential mSemicon & UCD19/04/23
Connectors – Power Board uses 12Vin, but also supplies 12Vout to feed Processor Unit
Requires compact multi-pole solution Needs to be robust, and not subject to loosening due to vibration
Needs to snap into position Propose Mini-Fit Jr™ 5569 from Molex
Or equivalent from Würth
17Confidential mSemicon & UCD19/04/23
Audio I/O – Audible and Ultrasonic
Both pairs of microphones will be installed on daughterboard(s) “Both” meaning audible and ultrasonic
Main board will be upside-down Daughterboard will be suspended underneath
The relative orientation of daughter-boards, if two, has to be decided
Alternative could be a small single board with four microphones, pairs mounted at extremities
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Dimensions
Circuit board layout not started yet Connectors have a very important bearing on overall size
Issue to be settled Orientation of PIR sensor and microphone daughterboard important
Propose DIN style for general inputs Can accommodate 4 pairs each
Dimensions are expect to be in the range of 120mm x 170mm
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Near-term Schedule
Layout to begin 15/12/08 Scheduled to finish late January Bare boards available first week of February Will be built up and debugged gradually
HW: PS, processor, ... SW: Linux USB driver (SPI & CPU bus), FPGA VHDL (in progress), Micro
board support Best case scenario is 6 weeks after board arrives for first sample
With partial driver and board support package functionality Likely scenario is 9 weeks after board arrives for first sample
20Confidential mSemicon & UCD19/04/23