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27 Nov 2007. Individual sensor about 5-6 times more sensitive using 6 inch unshielded 20 gauge wire for antenna. Tried straight vertical antenna, which begins registering my hand within about two inches. Then coiled it into a 1.5 inch loop, which was more sensitive for an approaching flat hand in the plane of the loop (like a Theremin volume control). Next I made a loop about 4 inches in diameter, which was sensitive to a flat hand from about 6 inches and sensitive to a few fingers poked through it. When approached from edge of loop instead of face, it responds within about 3-4 inches (as does straight vertical antenna).
26 Nov 2007. I soldered wires to each of the sensor boards and female headers to the TV2 processor board. Hooked it up to BASIC Stamp 2 using the Board of Education and wiring diagrams in manual. I didn't have antennas attached to sensor boards, just 5" shielded 22 gauge wires stripped about a half an inch at the ends. I had to use pin 12 of the 74HC4040 chip (U4) to get a reasonable signal, which dipped as expected when I moved my hand to within an inch or so of the stripped end of each antenna lead. Each sensor seemed to work as expected when I ran the BS2 program from the TV2 manual. Some values were lower to begin with (detecting table edge? need to check). Next, try with antennas. (WJT)
' {$STAMP BS2}
' {$PBASIC 2.5}
' Runs the Theremin Vision 2 and displays raw output numbers
' p0 of BASIC Stamp 2 connected to TV2 Sensor Stop
' p1 of BS2 connected to TV2 Select A
' p2 of BS2 connected to TV2 Select B
' p4 of BS2 connected to TV2 pin 12 of 74HC4040
' sensor input variables
sensor0 VAR Word
sensor1 VAR Word
sensor2 VAR Word
sensor3 VAR Word
' 0 = sensors on, 1 = sensors off
stoppin PIN 0
selecta PIN 1
selectb PIN 2
' set pins 1-3 for output
DIRA = 7
' pulse input
signalin PIN 4
'clear output screen
DEBUG CLS
start:
GOSUB scan
GOSUB display
GOTO start
' scan four sensors, pausing to allow each to stabilize, and store the pulse widths
scan:
selecta = 0 : selectb = 0
PAUSE 1
PULSIN signalin, 1, sensor0
selecta = 1 : selectb = 0
PAUSE 1
PULSIN signalin, 1, sensor1
selecta = 0 : selectb = 1
PAUSE 1
PULSIN signalin, 1, sensor2
selecta = 1 : selectb = 1
PAUSE 1
PULSIN signalin, 1, sensor3
RETURN
' display sensor data to screen
display:
DEBUG CRSRXY,20,7,SDEC5 sensor0," "
DEBUG CRSRXY,10,7,SDEC5 sensor1," "
DEBUG CRSRXY,10,2,SDEC5 sensor2," "
DEBUG CRSRXY,20,2,SDEC5 sensor3," "
RETURN
