DAS6070
From [WearLab]
Contents |
PCI DAS6070 Measurement Card
from Measurement Computing ( http://www.measurementcomputing.com/ )
Picture:
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respectively linked from Measurement Computing:
Drivers:
http://www.measurementcomputing.com/cbicatalog/cbiproduct.asp?dept_id=265&pf_id=1148
Manuals: http://www.measurementcomputing.com/PDFmanuals/pci-das6070.pdf
DAS6070 Periphery
BlackBox - Interface-Box
'Binder' 7-Pin Connectors
On the Box: Farnell 1122567 On the Cable: Farnell 1122560
Pinout:
1 = +5V 2 = GND ( connected LLGND ) 3 = -5V 4 = DAC Out 5 = DAC Gnd ( or DIO - needs rewiring for that. 26.Oct.2007 ) 6 = ADC In a ( Reference LLGND ) 7 = ADC In b ( Reference LLGND )
Connector 1 - Reference to DAS6070 Signals:
4, DAC Out = D/A Out0 5, DIO = DIO0 6, ADC In a = CH0 IN 7, ADC In b = CH1 IN
Connector 2 - Reference to DAS6070 Signals:
4, DAC Out = D/A Out1 5, DIO = DIO1 6, ADC In a = CH2 IN 7, ADC In b = CH3 IN
Pinout Micromatch 12pin to Binder 7pin:
1-1, 2-2, 3-3 and so on - pins after 7 are left unused
External Sensor Modules
Radar
Radarhead IVS24-2-4-2-162:
K-Band VCO Transceiver from InnoSent Datasheet: http://www.mdtcorp.com/prodfiles/PS-162.pdf Pinout: Page 18 of manual
Radarhead Pre-Amplifier
IR
IR Sensormodule TPA81
Thermopile Array - Infrared-sensitive 8 pixel array, analog Datasheet of I²C Module: http://www.active-robots.com/products/sensors/devantech/tpa81.pdf Pinout: Page 3 of manual
Perkin Elmer IR Sensor 3428:
8 Element Linear Thermopile Array TPL in TO39 case Pinout: Place sensor with the lens onto the desk in front of you. Align the little metal nose on the TO39 case to be straight to the left. The pin below and toward you we call Pin 1, the pin above and further away, we call Pin 2. The adjacent pin, even further away, we call Pin 3. We proceed further clockwise, the following pins labelled 4,5 and 6 accordingly. Thus, the pinout is as follows: 1 - Time Divided Data Signal Out ( Sync, Ambient, 8* IR receiver ) 2 - +5V 3 - GND 4 - Time Division Signal Single Cell Switch INPUT (?) 5 - Time Division Signal Single Cell Switch INPUT (?) 6 - Sensor Enable / NewLine INPUT
Changes necessary to operate on the DAS6070:
Disconnecting the Sensors output ( Pin 1 ) from the MCU's input and rerouting it to an unused pin of the sensormodules SIL connector. To do so, the coppertrace running from pin 1 of the sensor is to be cut, and the coppertrace connecting pin 4 of the SIL connector of the sensormodule. Pin 4 is the second pin of the 5-pin header counted from the side near the 3-pin connector. Then an as-short-as-possible cable is soldered from pin 4 of the SIL connector to pin 1 of the sensor.
IR-Head Pre-Amplifier
Extended Functions Connector
Micromatch 12pin
Pin = Function = Cable Color = DAS6070 connector board 1 = +5V = Red 2 = GND ( ref LLGND ) = Black 3 = -5V = Blue 4 = DAC Out 0 = Gray = 36 - Optional: MAG Degauss for 3D Magnetometer 5 = DIO 0 ( LOW = Enable Radarhead ) = Brown = 85 - Optional: 3D MAG Z Axis 6 = ADC in 0 ( Radar I ) = Green = 2 7 = ADC in 1 ( Radar Q ) = Yellow = 4 8 = ADC in 2 ( X axis accel ) = Green-White = 6 9 = ADC in 3 ( Y axis accel ) = Green-Brown = 8 10 = ADC in 4 ( Z axis accel ) = Red-Blue = 10 11 = Not Yet defined = Pink - Optional: 3D MAG Y Axis 12 = Not Yet defined = White - Optional: 3D MAG X Axis
B. Project Components
The B. Project required a number of different hardware components such as sensors and support-systems. Here is the compilation of the devices developed and built, plus their documentation.
Blocksheme:
Handheld Unit - Radar and Accelerometer
Theory of operation:
The radarsignals from the radarhead are bounced off the skin and the underlying tissues. Due to the uneven structure of both the surface ( pores, hairs ) and the underlying tissues ( bloodvessels, fat-tissues, muscles, bones ) moving the radar over the body should produce varying signals. Tilting the radarhead to look at the skin at a 45 degree angle should result in signal-reflecting properties of the skin to either close in or move away from the radarhead, depending upon direction of movement, which should be clearly detectable along with the speed of the actual movement.
The accelerometer supports the soft- and hardware processing the radaheads signals by providing information about accleration, deacceleration and degree of tilt in respect to the earths gravity field.
Circuit Diagram:
Note:
The Magnetometer was not fitted. The position of the device relative to the earths magnetic field did not promise any new informations compared to the accelerometers detection of gravity and movement and, combined with the problems of is degaussing circuits power consumption, the effort of fitting it, though, seemed inappropiate / ineffective / overly complex.
Power Supply:
The power for the Handheld is provided by the DAS6070. To reduce noise from the PC in the powersupply, the powersupply is provided by means of a DC-DC converter ( NMH0505DC - refer to http://www.cd4power.com/data/power/ncl/kdc_nmh.pdf ), providing a bipolar powersupply for the Radars amplifiers and permitting the GND level to be tied to LLGND ( DAS 6070 Pin 1 ). Capacitors before the DC-DC converter and behind it reduce noise further.
Components:
The radar module, an <A HREF="http://www.mdtcorp.com/prodfiles/PS-162.pdf"> InnoSent K-Band VCO-Tranceiver type IVS24-2-4-2-162 </A> operating at 24.125 GHz, is run with a fixed varactor tuning voltage of +5V. The signals of the I and Q output of the Radar are first bias-corrected, then they are amplified with the multiplicator of 6.7 and then connected to the DAS6070
Radar Pinout and Connections:
Radar Pin - Function - Connects to 1 - Varactor - +5V 2 - Enable - GND 3 - Power - +5V 4 - GND - GND 5 - I nphase - DAS6070 Pin 2 ( via BIAS & Amp ) 6 - Q uadrature - DAS6070 Pin 4 ( via BIAS & Amp ) 7 - Not Connected 8 - Not Connected 9 - GND - GND 10 - GND - GND
The Accelerometer, a <A HREF="http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MMA7260QT&fsrch=1">Freescale MMA7260Q</A> 3-Axis unit, is connected directly to the DAS6070. It is powered from a 3.3V LT1129CST3.3 Linear Technology 'Low Dropout Regulator'. Periphery consists out of RC-Lowpass filters for all three axis. Sensitivity is set for a +/- 1.5g range.
Accelerometer Pinout and Connections:
1 - g-select 1 - GND 2 - g-select 2 - GND 3 - VDD - +3.3V 4 - VSS - GND 5 - NC - 6 - NC - 7 - NC - 8 - NC - 9 - NC - 10 - NC - 11 - NC - 12 - Sleep Mode - +3.3V 13 - Z-Axis - DAS6070 Pin 10 14 - Y-Axis - DAS6070 Pin 8 15 - X-Axis - DAS6070 Pin 6 16 - NC -
Optional: 3D Magnetometer
As an option a <A HREF="http://www.ssec.honeywell.com/magnetic/datasheets/HMC105X.pdf">Honeywell HMC1053 3D-magnetic sensor</A> can be attached. However, the power drawn to degauss the unit puts a heavy strain on the power supply of the handheld as a whole.
3D Magnetometer Pinout and Connections:
"A" = X ; "B" = Y ; "C" = Z 1 - VB - +5V 2 - OFF- (A,B) - NC 3 - S/R+ (A,B) - degauss - HEXFET to +5V 4 - OUT- (B) - DAS6070 Pin 14 ( via inverting Input of OpAmp 2 ) 5 - GND (B) - GND 6 - S/R+ (C) - degauss - HEXFET to +5V 7 - OFF- (C) - NC 8 - S/R- (A,B,C) - GND 9 - OUT- (C) - DAS6070 Pin 12 ( via inverting Input of OpAmp 3 ) 10 - OUT- (A) - DAS6070 Pin 16 ( via inverting Input of OpAmp 1 ) 11 - GND (A) - GND 12 - OUT+ (B) - DAS6070 Pin 14 ( via non-inverting Input of OpAmp 2 ) 13 - OUT+ (C) - DAS6070 Pin 12 ( via non-inverting Input of OpAmp 3 ) 14 - GND (C) - GND 15 - OFF+ (A,B,C) - NC 16 - OUT+ (A) - DAS6070 Pin 16 ( via non-inverting Input of OpAmp 1 )
Ultrasonic Generator - Transmitter and Receiver circuitry
Theory of operation:
To assist the handheld unit respectively the soft- and hardware using its sensors it recognizing and tracking movements, an external system to measure movements of the handheld unit relative to a fixed position based on ultrasound was implemented.
A quarz-stable 40kHz signal is generated and drives an ultrasonic transmitter (refer to UST-40T ; http://www.reichelt.de/?;ACTION=3;LA=4;GROUP=B6;GROUPID=3190;ARTICLE=22188;START=0;SORT=preis;OFFSET=76;SID=27rP@TG6wQARsAAD@SUz4d0172ef2312005db3d1a2694bccfa503 ), whilst a 10000 times (100 x 100) amplifier boosts the received signal (refer to UST-40R ; http://www.reichelt.de/?;ACTION=3;LA=4;GROUP=B6;GROUPID=3190;ARTICLE=22187;START=0;SORT=preis;OFFSET=76;SID=27rP@TG6wQARsAAD@SUz4d0172ef2312005db3d1a2694bccfa503 ) and puts it to a Schmitt-Trigger for turning the resulting signal into a squarewave.
The received signal and the original 40kHz signal are then available for further processing.
Circuit Diagram:
Powersupply:
The Ultrasonic Generator module is supplied by an external switching power supply with its own 5V supply to prevent high frequency peaks from the digital counters and the Quarz-Oscillator to be introduced into the low frequency analog components such as the radar and the accelerometer.
Mechanical Setup:
The ultrasonic transmitter is connected externally using a long, shielded cable to the handheld unit carrying the radar and accelerometer sensor. The receiver is built into the box carrying the Ultrasond Generators electronics, and can be placed within line of sight to receive the signal. As only the change in distance needs to be measured for testign and calibrating purposes, there is no need for a particular distance or arrangement to be choosen, except for the avoidance of sources for ultrasonic echos.
Ultrasonic Support Systems - Optocoupler and HF-clock-Generator
Theory of operation:
The optocouplers ensure galvanic decoupling and thus prevent electric interferences such as groundloops between the DAS6070 and the Ultrasonic Generator. However, translating the generated and the received 40kHz signals is not enough for the way we intend to use the DAS6070. Using a 4011 NAND-Gate the two signals are combined into a single signal, which is used to do three things:
1) Indicate on Pin 86 of the DAS6070 whether the counter is busy or not
2) Reset the counter with it's rising edge
3) enabling or disabling a NOR gate to switch a high frequency (3 MHz) clock signal to the counters input
The effect of this setup is as follows:
1) As long as Pin 86 of the DAS6070 Connector ( = DIO1 ) is read as being HIGH, Counter 1 is busy and thus does not need to be read.
2) Whenever Pin 86 is going to HIGH level, Pin 94 ( = CTR1 GATE ) is going high, too, and the levelshift from low to high effects a reset of Counter 1.
3) The clock signal for Counter 1 being provided only for the same duration as Pin 86 is pulled HIGH.
This again means the following:
3a) The more in Sync the generated and the received signal are, the longer the time during which the high frequency clock signal makes the Counter 1 count.
3b) The further out of sync, the shorter the time Conter 1 is clocked.
3c) As every change in distance of the transmitter in reference to the receiver means a phaseshift of the received signal in comparison to the generated one, every change in distance will result in a varying value in Counter 1.
3d) Thus movements and their speed can be measured by the change of the value in Counter 1 compared over time, and the time when to read the counter is the time during which Pin 86 is at a LOW level.
Circuit Diagram:
Note:
Informations about direction of movement could be retrieved from the signals, too, but the additional hardware was not implemented as the direction of movement can be retrieved from the accelerometer sensor.
Power Supply:
The Optocouplers LEDs are connected to the GND and signal lines of the Ultrasonic Generator, whilst their photodiode-parts are connected to the +5V/GND provided by the DAS6070.
