WIRELESS ACCELEROMETER

Transcription

1 WIRELESS ACCELEROMETER Fall Semester 2018 CAPTSTONE DESIGN TOPIC SUBMITTED BY: INSTRUMENTED SENSOR TECHNOLOGY, INC 4704 Moore St. Okemos, MI The Wireless Accelerometer device is a 3-axis accelerometer/logger that also provides real time data output via Wi-Fi or Blue-Tooth to a Smartphone type device. The device operates with an SPI data interface from the MEMs accelerometer to the processor. During ACTIVE recording mode the processor samples the accelerometer signal at a user selectable sample rate. The processor performs a peak/hold on sampled accelerometer axial values and saves the maximum acceleration g-level over preset time bin (intervals), for each axis individually, along with the date/time that the peak level occurred at for each axis. Saved in data memory is a listing of peak-g levels for each axis with date/times over n number of respective time bins. Periodically over user selectable time intervals the device will wake up the blue tooth or Wi-Fi interface to communicate to the SmartPhone. Once communication is established the device will transmit to the smartphone: 1. The serial number of the device 2. The current x, y, and z peak g level for the current time bin along with date/times of occurrence. This information will then be displayed on the smartphone. 3. Query the smartphone whether to transmit the entire data set collected(all time bins) or continue recording function 4. If the user requests to transmit all data then the smartphone will receive all data from the device including Bin #, peak x, y, z data; date/times of each peak reading

2 5. After data download the SmartPhone will save the data in a file that can later be transmitted or ed to another device or PC. 6. The device will then ask the Smartphone whether to re-set memory and start a new recording session, continue current recording session, or reconfigure recording control parameters(rcps). The recording control parameters are the sample rate, bin size, communications wake-up interval, number of time bins, and current date/time(from the SmartPhone). These are the RCPs. 7. After parameter reset the device will ask the smartphone whether to re-start recording session or wait in standby mode. In standby mode the device will go to sleep and wake up for communications periodically during the wake-up interval time periods for SmartPhone communications. During ACTIVE recording mode, at the end of each time bin when saving the peak readings, the device will also attempt to establish smartphone communications and then transmit the current saved peak-g readings along with date/time of occurrence for real time display. After communications the device will continue ACTIVE recording in the next time bin. The device will also have a pushbutton on the side of the unit. The pushbutton will be used to manually cycle the unit between COM mode and ACTIVE (recording) mode. If the unit is cycled to COM mode then the unit will remain in COM mode for three minutes awaiting communication with the smartphone. If no communications takes place then then unit will go to hibernate (low power mode) until the pushbutton is used to cycle the unit back to COM mode or to ACTIVE mode. If the unit is cycled to ACTIVE mode then the unit will resume and/or restart data collection. During initial COM mode entry the device will ask the smartphone to set all recording control parameters and proceed to do so. During ACTIVE recording once the device reaches the nth time bin the device will remain in the nth time bin, until reset. The unit will operate from either a single nine volt or dual lithium AA batteries. Battery life is critical and the highest battery life is desirable (weeks if possible) The unit will also be housed in IST s SnapShock-Plus housing. Dimensions attached.

3 SPECIFICATIONS Recording Control Parameters (RCPs) Sample rate: user selectable from 100 sps/channel to 3200 sps/ch Time bin size: user selectable from 500msec to 7 days Wake Up(COM) intervals: user selectable from constant to 3sec to 5min Number of time bins: from 1 to 10,000 Fixed Parameters Full scale g-range: 200g (ADXL372) Digitization: 12-bit minimum Anti-Aliasing filter: auto adjusted in ADXL Size: 1.6 x3.2 x1.5 (see attached housing drawings) Weight: no spec Operating temperature: -40 to +70 deg C Battery life: 2 weeks minimum Initial Report Data Required: 1. Schematic and/or PCB layout files 2. Microcontroller/processor firmware/source listing & file 3. Smartphone applications source code 4. Chart/graph of device power consumption versus sample rate 5. Power consumption data for ACTIVE mode versus COM mode

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6 +0.005" 2.400" " MAKE A 0.050" DEPRESSION FOR IR PLATE, DWG#S9138P0-1 MAKE SHARP CORNER TO FIT WINDOW COVER PIECE 1/16" R 4 PLACES 1/8" DIA ROUND EDGES SLIGHTLY DRILL & TAP FOR #6-32 NC 1/2" SCREW 4 PLACES TO MATE WITH CORNER HOLES IN TOP PLATE. REF DWG # H9138M0-2 SEE NOTES: " 0.670" " SEC A REF C OF BODY SEC B " 2.400" " " 1.220" " SEC B 0.400" 0.400" SEC A SEE NOTE 4 SEC B B 0.050" 0.400" 0.760" 0.710" 0.400" 1.470" 2 HOLES REF DWG #H9138M0-11 FOR LOCATION AND SPECIFICATIONS REF C OF BODY CAVITY 1.270" 0.125" 0.110" 0.500" DRILL & TAP FOR #4-40 NC ROUND HEAD SCREW 4 HOLES DRILLED THROUGH SEE NOTES: 2 7 CENTER LINE FOR 1/4" HOLE #53 HOLE DRILL & TAP FOR 1-72 NF SCREW 2 PLACES 0.325" 0.190" 0.800" 0.400" 3.200" 1.200" 1.200" 2.150" 1.075" SECTION A-A REF C OF OBLONG HOLE 0.120" R 2 PLACES 0.170" DIA. HOLE 0.710" 1/4" DIA. HOLE 0.230" 0.735" 0.760" 0.230" 0.735" DRILL & TAP FOR #6-32 NC 1/2" SCREW 4PLACES TO MATE WITH THE CORNER HOLES IN THE BOTTOM PLATE REF DWGS# H9138M0-3 & H9138M0-12 REV 4 : CHANGED HOLE TO 0.170" (SWITCH) ADD LEADER NOTE FOR CENTERLINE OF 1/4" HOLE (CONNECTOR) " 0.760" SEE NOTES: 1 NOTES \\IST01\@Jupiter\hard-fabrication\SS-Plus.project.chumblspuz\SnapShock_Mechanicals\Snapshock_Hsg_Vcadd_h9138v3\h9138m1.vcd 7/30/ CLEAR ALL DRILL AND THREADING CHIPS FROM HOLES THREADED DEPTH OF HOLES SHOULD BE.600 MAX.550 MIN " 0.295" 0.485" 0.970" ALL TOLERANCES SHALL BE 0.245" 0.245".003 UNLESS OTHERWISE NOTED DEBURR THREADED HOLES WITH.02" X 45 CHAMFER OR.166 DIA COUNTER DRILL.03 DEEP DEBURR THREADED HOLES TO ENSURE THAT SURFACES ARE FLAT 1/16" R MAX FILLET 4 PLACES BODY MATERIAL 6061 ALUMINUM BLACK (37038) SATIN ANODIZED FINISH 1/16" R MAX 8 PLACES R 4 PLACES RADIUS FROM CENTER OF 4-40 HOLE 1/8" R 4 PLACES 1 DRILL HOLES SHOULD EXTEND TO MEET OPPOSITE HOLES TO FACILITATE CHIP REMOVAL R MAX FILET BETWEEN SIDE WALLS AND BOTTOM IN BOTH CAVITIES TO MINIMIZE EXPOSED AREAS. EXAMPLE: USE OF SCREW HOLES WOULD BE ACCEPTABLE REF C OF BODY CAVITY CONTACT POINTS FOR ANODIZING SHOULD BE THE INSIDE ON A NON-VISIBLE SURFACE AREA SSR9138 SNAPSHOCK PLUS HOUSING BODY J.DOBIAS S.LASSINI H9138M0-1 FULL SIZE OF 13 4