manufacturer page has most of the information, however the remote display protocol isn't documented.
Here are my notes:
The remote display uses a string of 73 pulses. A long pulse (250uS?)
is a 1 and short pulse (125uS?) is a 0. Pulses occur every (300?) 500uS and
the group occurs every 50mS or 20 times per second (the 73 pulses work
out to 36.5mS). It needs a pulldown - the actual display uses about
4k, but 50k also seems to work. Note that shorting the wrong pins on
the connector can damage the detector.
If you use an inverting TTL to RS232 converter (e.g. a MAX3232 or Jim Mitchell's circuit Here
M - muted
= - laser ahead (solid)
? - always zero so far
+ - always one
a L ^
b f A
g K -
c e X v
1 2 3 4 5 6 7 8
Symbols displayed on the 7 segment:
(= represents triple horizontal for laser)
(decimal point flashes at startup if Ku is active)
long pulse (2/3) = 0, short (1/3) = 1
00 Always 1
02 7 seg lower left
03 7 seg bottom
04 7 seg lower right
05 7 seg upper right
06 7 seg top
07 7 seg - decimal point
08 Signal Strength 8 (max)
09 Signal Strength 7
10 Signal Strength 6
11 Signal Strength 5
12 Signal Strength 4
13 Signal Strength 3
14 Signal Strength 2
15 Signal Strength 1 (min)
16 7 seg middle
17 7 seg upper left
18 K Band indicator
19 Ka Band indicator
20 Laser indicator
21 Ahead arrow
22 Laser Ahead (solid even when bit 20 flashes)
23 Laser Ahead (solid even when bit 20 flashes)
24 Side arrow (all three bits)
25 Side arrow
26 Side arrow
27 Behind arrow (all three bits)
28 Behind arrow
29 Behind arrow
30 Always 0 in current tests (Ku, oather modes untested).
31 X Band indicator
The remainder are always 0
REMOTE AUDIO and GENERAL AUDIO NOTES
(from a connector that went into my laptop
with the datastream on the left channel and remote audio out on the right at 48khz)
It uses a greater resistance pullup than the remote display (the rise times are much slower) and this is detected by the main unit and will produce a modified datastream.
There are four basic squarewaves (based on 48khz):
X beep is 70 cycles of A
K and Ka use a composite of 4A followed by 4D, that is four A waves, then four D waves which makes the brap sound.
K beep is 13 cycles of (4A4D)
Ka is 9 * (4A4D), a gap of 1175 samples (note this figure includes the lowtime of the next first wave) then 9 more (4A4D).
Laser is 128A208B (lowtime of first A is 20, not 28
Bogey increment is 96C, 2073 samp gap (incl following lowtime), 96C, 8137 samp gap, then resumes radar beeps
J) is 79C, 2558 gap, 79B, 2558 gap, 79A.
The start and mute bits are the same.
The next 16 bits indicate which band and signal level but the pattern isn't straightforward and is very different from the remote display, however if the remote display is also attached, the datastream will be that of the remote display and the remote audio will work.
Another approx 18 bits are used for the bogey count up and junk tones (involving tone C).
(I don't know about the laser).
Following bits are always zero as they are with the remote display.
The timing which forms the Geiger counter effect seems to be a moving average - when the strength bounces between two values the time between beeps will be between.