Alarm System
Archiver
Posts: 46,084
Is there any thing I should know before making an alarm using a
lazer (Lazer pen with switch activated with a servo or similar)?
I am going to use a LDR, and using the RCTIME function, detect
when it gets darker (The beam is broken)
Is there any thing I should change about this?
Here is the code so far ::
'******************* Start Code *********************'
'***************************************
'* Beam Break Alarm System * D *
'* //// //// ////// ///// * B *
'* // // // // // // // * R *
'* //// //// ////// ///// * W *
'* // // // // // // // * e *
'* //// //// // // ///// * b *
'*********************************** . *
'* Use a lazer onto a LDR, when * c *
'* someone walks though the beam * o *
'* the alarmm goes off * . *
'* * u *
'* * k *
'***************************************
'* Vars and cons '*
alarm_status VAR word '*
ldr_act_on VAR word '*
ldr_lzr_in CON 0 '*
srt_bbas CON 1 '*
spkr CON 2 '*
alarm_out CON 3 '*
ldr_op VAR word '*
'***************************************
debug cr
debug "DBRWeb.co.uk",cr
debug "Beam Break Alarm",cr
debug "BBAS (c) DBR 2002",cr,cr
hold:
IF srt_bbas = 0 THEN hold ' Wait for button
bbas_check: ' Check loop
rctime ldr_lzr_in, 1, ldr_op ' Get the LRD status
debug ldr_op, cr ' DEBUG
status (Comment to remove)
ldr_act_on = ldr_op ' Store var to another
if ldr_act_on > 100 THEN start_alarm ' Check
GOTO bbas_check ' Repeat back to bbas:
start_alarm: ' Start alarm loop
alarm_status = "1" ' Set the alarm status
high alarm_out ' HIGH alarm out pin
(externam connections)
cont_alarm: ' Alrm sounds
loop
freqout spkr, 1000, 100 ' Start internal siren
pause 50 ' Short pause
GOTO cont_alarm ' Repeat
END ' Not needed
'********************* End Code *********************'
I am sure that there is a lot wrong with it, as I have yet to test it
fully
Thanks
- Ben
lazer (Lazer pen with switch activated with a servo or similar)?
I am going to use a LDR, and using the RCTIME function, detect
when it gets darker (The beam is broken)
Is there any thing I should change about this?
Here is the code so far ::
'******************* Start Code *********************'
'***************************************
'* Beam Break Alarm System * D *
'* //// //// ////// ///// * B *
'* // // // // // // // * R *
'* //// //// ////// ///// * W *
'* // // // // // // // * e *
'* //// //// // // ///// * b *
'*********************************** . *
'* Use a lazer onto a LDR, when * c *
'* someone walks though the beam * o *
'* the alarmm goes off * . *
'* * u *
'* * k *
'***************************************
'* Vars and cons '*
alarm_status VAR word '*
ldr_act_on VAR word '*
ldr_lzr_in CON 0 '*
srt_bbas CON 1 '*
spkr CON 2 '*
alarm_out CON 3 '*
ldr_op VAR word '*
'***************************************
debug cr
debug "DBRWeb.co.uk",cr
debug "Beam Break Alarm",cr
debug "BBAS (c) DBR 2002",cr,cr
hold:
IF srt_bbas = 0 THEN hold ' Wait for button
bbas_check: ' Check loop
rctime ldr_lzr_in, 1, ldr_op ' Get the LRD status
debug ldr_op, cr ' DEBUG
status (Comment to remove)
ldr_act_on = ldr_op ' Store var to another
if ldr_act_on > 100 THEN start_alarm ' Check
GOTO bbas_check ' Repeat back to bbas:
start_alarm: ' Start alarm loop
alarm_status = "1" ' Set the alarm status
high alarm_out ' HIGH alarm out pin
(externam connections)
cont_alarm: ' Alrm sounds
loop
freqout spkr, 1000, 100 ' Start internal siren
pause 50 ' Short pause
GOTO cont_alarm ' Repeat
END ' Not needed
'********************* End Code *********************'
I am sure that there is a lot wrong with it, as I have yet to test it
fully
Thanks
- Ben
Comments
lazer (Lazer pen with switch activated with a servo or similar)?
I am going to use a LDR, and using the RCTIME function, detect
when it gets darker (The beam is broken)
Is there any thing I should change about this?
Here is the code so far ::
'******************* Start Code *********************'
'***************************************
'* Beam Break Alarm System * D *
'* //// //// ////// ///// * B *
'* // // // // // // // * R *
'* //// //// ////// ///// * W *
'* // // // // // // // * e *
'* //// //// // // ///// * b *
'*********************************** . *
'* Use a lazer onto a LDR, when * c *
'* someone walks though the beam * o *
'* the alarmm goes off * . *
'* * u *
'* * k *
'***************************************
'* Vars and cons '*
alarm_status VAR word '*
ldr_act_on VAR word '*
ldr_lzr_in CON 0 '*
srt_bbas CON 1 '*
spkr CON 2 '*
alarm_out CON 3 '*
ldr_op VAR word '*
'***************************************
debug cr
debug "DBRWeb.co.uk",cr
debug "Beam Break Alarm",cr
debug "BBAS (c) DBR 2002",cr,cr
hold:
IF srt_bbas = 0 THEN hold ' Wait for button
bbas_check: ' Check loop
rctime ldr_lzr_in, 1, ldr_op ' Get the LRD status
debug ldr_op, cr ' DEBUG
status (Comment to remove)
ldr_act_on = ldr_op ' Store var to another
if ldr_act_on > 100 THEN start_alarm ' Check
GOTO bbas_check ' Repeat back to bbas:
start_alarm: ' Start alarm loop
alarm_status = "1" ' Set the alarm status
high alarm_out ' HIGH alarm out pin
(externam connections)
cont_alarm: ' Alrm sounds
loop
freqout spkr, 1000, 100 ' Start internal siren
pause 50 ' Short pause
GOTO cont_alarm ' Repeat
END ' Not needed
'********************* End Code *********************'
I am sure that there is a lot wrong with it, as I have yet to test it
fully
Thanks
- Ben
> Is there any thing I should know before making an alarm using a
> lazer (Lazer pen with switch activated with a servo or similar)?
>
> I am going to use a LDR, and using the RCTIME function, detect
> when it gets darker (The beam is broken)
>
> Is there any thing I should change about this?
>
I believe most if not all LDRs have very slow reaction times. I
have tried a similar setup and found that it was indeed too slow
to detect fast breaks in the beam (say less than 5 ms). You
might want to consider using a photo diode instead unless you're
only concerned with slow moving objects.
Michael Burr
--
Our government it seems has got a new plan...
Seize and search the private records of every man.
No warrants, no judges, no due process required,
With "Homeland Security" the 4th Amendment's retired.
"Total Information Awareness" the project is called,
Oh would our forefathers be aghast and appalled!
http://geocities.com/totalinformationawareness/
most likely designed to be turned on for a few seconds at a time.
The alarm reliability is compromised if the pen burned out after 30 min of
operation.
Alan Bradford
Plasma Technologies
[noparse][[/noparse]Non-text portions of this message have been removed]
alarm like this the trick is to pulse modulate the laser then use
a photodiode to detect it you can use a 555 timer chip setup as a
missing pulse detector hook that output to the stamp then you shoudnt
have to worry about any delay after the beam is broken
This is what I used for a laser beam break detector, it just changes logic
state when beam is broken. It worked absolutly perfectly. I powered the
keychain laser with a 9V battery for longer life, and I did indeed run the
unit for hours at a time. I placed the photocell a couple of inches deep in
a tube so that ambient light would not effect it. It was completely immune
from ambient light effecting the circuit. Its funny because I put this
schematic up for the basic stamp users years ago, and I don't even have the
same ISP anymore but they still host my images.
--Dan
dankgus@p...
Original Message
From: <plasmastamp@a...>
To: <basicstamps@yahoogroups.com>
Sent: Monday, January 20, 2003 9:26 AM
Subject: Re: [noparse][[/noparse]basicstamps] Alarm System
> The first thing that comes to mind is the duty cycle of the Laser Pen. It
was
> most likely designed to be turned on for a few seconds at a time.
> The alarm reliability is compromised if the pen burned out after 30 min of
> operation.
>
> Alan Bradford
> Plasma Technologies
> http://home.earthlink.net/~dankgus/SCHEMATICS/photocell.bmp
>
Dan, I'd really like to look at this circuit, but all I get from
my browser is garbage when I try this link - try as I might, I
can't seem to get it to accept this bitmap file. Is there a ftp
proceedure that can be used to acquire a copy of the file?
If not would it be possible for you to send me a copy as an
attachemnt? (mburr@b...).
Thanks,
Michael Burr
Hold down CTRL key and left click on the link.
It'll do the trick in Netscape.
Jan
Michael Burr wrote:
>Dan Gustafson wrote:
>
>
>
>>http://home.earthlink.net/~dankgus/SCHEMATICS/photocell.bmp
>>
>>
>>
>
>Dan, I'd really like to look at this circuit, but all I get from
>my browser is garbage when I try this link - try as I might, I
>can't seem to get it to accept this bitmap file. Is there a ftp
>proceedure that can be used to acquire a copy of the file?
>
>If not would it be possible for you to send me a copy as an
>attachemnt? (mburr@b...).
>
>Thanks,
>
>Michael Burr
>
>
>To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
>from the same email address that you subscribed. Text in the Subject and Body
of the message will be ignored.
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>
>
>
>
>
[noparse][[/noparse]Non-text portions of this message have been removed]
> Michael,
> Hold down CTRL key and left click on the link.
> It'll do the trick in Netscape.
>
Thanks - actually turned out to need the SHIFT key instead of
CTRL... but I got it.
Michael Burr