On 2018-08-08, amdx <nojunk@knology.net> wrote:> On 8/6/2018 10:03 PM, Jasen Betts wrote: >> On Thursday, August 2, 2018 at 9:45:14 PM UTC-4, amdx wrote: >>> I want to hack the newer Driveway sensor. >>> I had the old ones all figured out, now they went to all surface mount >>> parts, with a different design. >>> I just want to a add a button to trigger the peizo alarm in the receiver. >>> It has an 8 pin chip labeled AT12L and 319H. >> >> Why not just buy a wireless doorbell? > > I had one of these driveway sensors modified and it worked fine for > years. My business is 3 steps down, I put the sensor on the middle step, > then when someone walked down the steps, the receiver was triggered and > the obnoxious noise from the piezo would wake me up. Then maintenance > changed the steps, the jerk must have been very curious what was inside > this pvc pipe. So he cut the wire and took it. When I ask him about it > he didn't know anything about it. He is what we call a liar. > So, now I'm modifying another one. I have to modify it because it will > trigger on every car that goes by, every pedestrian and every customer > that stands in front of my while we do business. Just want it to trigger > in that two or three foot area as they descend the stairs. > Doorbell, yes, I just wanted the doorbell button to cause the same > piezo to sound, that's in the driveway receiver. > >> >>> Can someone explain what is happening on pin 4 at trigger. >>> Is there a way to fool it with a simple switch, or is that a code that >>> the 319H is reading? >> >> no. but do you know how pyroelectric sensors are read? >> feed that input with a few Hz at low amplitude. >> >> -- >> ت >> > > No, I didn't but I did look at this site and got some idea. >> http://www.fuji-piezo.com/prodpyro.htm > > I'm still lost, as the rf section has that constant pulsing output that > changes when the receiver gets triggered.SFAIK they use OOK in the transmitter. The receiver adjusts the gain until it sees 50% signal It'll be receiving everything else that shares the same band (car remotes, door remotes, doorbells, noise, etc. So you'll get binary noise until a nearby transmitter comes on and the AGC pushes the noise floor down below the threshold.> I took the perfectly working assy, wallwart, voltage regulators, > receiver and sensor, which I had working just fine at home, down to the > business. > I wired it all up and installed the sensor where it needs to be and > the receiver, just will not stop beeping.I hate it when that happens :(> I'm going to try another section of the fresnel patterned window and > mount it differently. I have the PIR looking through a 1/2" piece of > tubing with the window on the end. (same as the old unit)I've seen similar units with black electrical tape covering most of the fresnel zones, resulting in a narrower view angle..> I tried twice to clean this off my screen --> ت > Eyes aren't what they used to be.:) I was looking through unicode for some reason and came across that character, and thought "He looks happy" -- ت
Haking the newer Harbor Freight Driveway Sensor
Started by ●August 2, 2018
Reply by ●August 8, 20182018-08-08
Reply by ●August 9, 20182018-08-09
On 8/8/2018 12:58 AM, Jasen Betts wrote:> On 2018-08-08, amdx <nojunk@knology.net> wrote: >> On 8/6/2018 10:03 PM, Jasen Betts wrote: >>> On Thursday, August 2, 2018 at 9:45:14 PM UTC-4, amdx wrote: >>>> I want to hack the newer Driveway sensor. >>>> I had the old ones all figured out, now they went to all surface mount >>>> parts, with a different design. >>>> I just want to a add a button to trigger the peizo alarm in the receiver. >>>> It has an 8 pin chip labeled AT12L and 319H. >>> >>> Why not just buy a wireless doorbell? >> >> I had one of these driveway sensors modified and it worked fine for >> years. My business is 3 steps down, I put the sensor on the middle step, >> then when someone walked down the steps, the receiver was triggered and >> the obnoxious noise from the piezo would wake me up. Then maintenance >> changed the steps, the jerk must have been very curious what was inside >> this pvc pipe. So he cut the wire and took it. When I ask him about it >> he didn't know anything about it. He is what we call a liar. >> So, now I'm modifying another one. I have to modify it because it will >> trigger on every car that goes by, every pedestrian and every customer >> that stands in front of my while we do business. Just want it to trigger >> in that two or three foot area as they descend the stairs. >> Doorbell, yes, I just wanted the doorbell button to cause the same >> piezo to sound, that's in the driveway receiver. >> >>> >>>> Can someone explain what is happening on pin 4 at trigger. >>>> Is there a way to fool it with a simple switch, or is that a code that >>>> the 319H is reading? >>> >>> no. but do you know how pyroelectric sensors are read? >>> feed that input with a few Hz at low amplitude. >>> >>> -- >>> ت >>> >> >> No, I didn't but I did look at this site and got some idea. >>> http://www.fuji-piezo.com/prodpyro.htm >> >> I'm still lost, as the rf section has that constant pulsing output that >> changes when the receiver gets triggered. > > SFAIK they use OOK in the transmitter. The receiver adjusts the gain until > it sees 50% signal > > It'll be receiving everything else that shares the same band (car > remotes, door remotes, doorbells, noise, etc. So you'll get binary noise > until a nearby transmitter comes on and the AGC pushes the noise floor down > below the threshold. > >> I took the perfectly working assy, wallwart, voltage regulators, >> receiver and sensor, which I had working just fine at home, down to the >> business. >> I wired it all up and installed the sensor where it needs to be and >> the receiver, just will not stop beeping. > > I hate it when that happens :(This morning I may have noticed why that happened! My business is on the water, 3 steps down to the dock. The dock is against a concrete wall that goes below the water line. I point my sensor at the concrete wall, not a problem, but, when they replaced the steps they also replaced dock boards. The original dock boards were 6'6" long, the replacements are 6 0" long, leaving a 6" gap along the wall. I noticed this morning the sun reflecting off the ripple of the water and hitting the wall. My theory is the rippling reflection though the gap was causing the continuous beeping. On my next test, I'll put a board over that gap. The marina owner saved money by cutting a 12' board in half, it cost me when a dropped phone went into the water through that gap. "It's always something" Mikek> >> I'm going to try another section of the fresnel patterned window and >> mount it differently. I have the PIR looking through a 1/2" piece of >> tubing with the window on the end. (same as the old unit) > > I've seen similar units with black electrical tape covering most of > the fresnel zones, resulting in a narrower view angle.. > >> I tried twice to clean this off my screen --> ت >> Eyes aren't what they used to be. > > :) I was looking through unicode for some reason and came across that > character, and thought "He looks happy" >
Reply by ●August 10, 20182018-08-10
On 2018-08-09, amdx <nojunk@knology.net> wrote:> > My business is on the water, 3 steps down to the dock. > The dock is against a concrete wall that goes below the water line. > I point my sensor at the concrete wall, not a problem, but, > when they replaced the steps they also replaced dock boards. > The original dock boards were 6'6" long, the replacements are 6 0" > long, leaving a 6" gap along the wall. I noticed this morning the sun > reflecting off the ripple of the water and hitting the wall. > My theory is the rippling reflection though the gap was causing the > continuous beeping.I had a similar problem with sunlight through tree-leaves. -- ت
Reply by ●August 11, 20182018-08-11
On Friday, August 10, 2018 at 4:31:21 PM UTC-4, Jasen Betts wrote:> On 2018-08-09, amdx <nojunk@knology.net> wrote: > > > > My business is on the water, 3 steps down to the dock. > > The dock is against a concrete wall that goes below the water line. > > I point my sensor at the concrete wall, not a problem, but, > > when they replaced the steps they also replaced dock boards. > > The original dock boards were 6'6" long, the replacements are 6 0" > > long, leaving a 6" gap along the wall. I noticed this morning the sun > > reflecting off the ripple of the water and hitting the wall. > > My theory is the rippling reflection though the gap was causing the > > continuous beeping. > > I had a similar problem with sunlight through tree-leaves.You guys know how the "motion" sensor works, right? They use a "lens" that causes a moving IR source to vary the intensity of the light falling on the photoreceptor. I haven't taken one apart, but I expect they use at least two photoreceptors so changes in overall brightness doesn't trigger the device. So light patches varying in intensity will trigger the device if they contain IR energy. A friend was talking about a sensor that was getting triggered at night outside her mother's home which upset the mother thinking someone was trying to get in. The daughter though the IR sensor was picking up tree branches moving since it is a "motion" detector. I tried to explain that the branches were the same temperature and so wouldn't trigger the detector. But then I realized, if a strong light were behind the branches it might have enough IR to trigger when the branches moved. She didn't see the need to involve a light source. Rick C.
Reply by ●August 11, 20182018-08-11
On 2018-08-11, gnuarm.deletethisbit@gmail.com <gnuarm.deletethisbit@gmail.com> wrote:> On Friday, August 10, 2018 at 4:31:21 PM UTC-4, Jasen Betts wrote: >> On 2018-08-09, amdx <nojunk@knology.net> wrote: >> > >> > My business is on the water, 3 steps down to the dock. >> > The dock is against a concrete wall that goes below the water line. >> > I point my sensor at the concrete wall, not a problem, but, >> > when they replaced the steps they also replaced dock boards. >> > The original dock boards were 6'6" long, the replacements are 6 0" >> > long, leaving a 6" gap along the wall. I noticed this morning the sun >> > reflecting off the ripple of the water and hitting the wall. >> > My theory is the rippling reflection though the gap was causing the >> > continuous beeping. >> >> I had a similar problem with sunlight through tree-leaves. > > You guys know how the "motion" sensor works, right? They use a "lens" that causes a moving IR source to vary the intensity of the light falling on the photoreceptor. I haven't taken one apart, but I expect they use at least two photoreceptors so changes in overall brightness doesn't trigger the device. So light patches varying in intensity will trigger the device if they contain IR energy. > > A friend was talking about a sensor that was getting triggered at night outside her mother's home which upset the mother thinking someone was trying to get in. The daughter though the IR sensor was picking up tree branches moving since it is a "motion" detector. I tried to explain that the branches were the same temperature and so wouldn't trigger the detector. But then I realized, if a strong light were behind the branches it might have enough IR to trigger when the branches moved. She didn't see the need to involve a light source.As I understand it: The sensor produces current as its temperature changes. The pyroelectric element has two cells and the lenses in adjacent zones of the window focus incoming infrared on opposite cells. the two signals are fed to opposite inouts of a op-amp and the amplitude of the output signal is checked -- ت
Reply by ●August 11, 20182018-08-11
On Aug 11, 2018, Jasen Betts wrote (in article <pkm847$s43$1@gonzo.alcatraz>):> On 2018-08-11, gnuarm.deletethisbit@gmail.com<gnuarm.deletethisbit@gmail.com> > wrote: > > On Friday, August 10, 2018 at 4:31:21 PM UTC-4, Jasen Betts wrote: > > > On 2018-08-09, amdx<nojunk@knology.net> wrote: > > > > > > > > My business is on the water, 3 steps down to the dock. > > > > The dock is against a concrete wall that goes below the water line. > > > > I point my sensor at the concrete wall, not a problem, but, > > > > when they replaced the steps they also replaced dock boards. > > > > The original dock boards were 6'6" long, the replacements are 6 0" > > > > long, leaving a 6" gap along the wall. I noticed this morning the sun > > > > reflecting off the ripple of the water and hitting the wall. > > > > My theory is the rippling reflection though the gap was causing the > > > > continuous beeping. > > > > > > I had a similar problem with sunlight through tree-leaves. > > > > You guys know how the "motion" sensor works, right? They use a "lens" that > > causes a moving IR source to vary the intensity of the light falling on the > > photoreceptor. I haven't taken one apart, but I expect they use at least > > two photoreceptors so changes in overall brightness doesn't trigger the > > device. So light patches varying in intensity will trigger the device if > > they contain IR energy. > > > > A friend was talking about a sensor that was getting triggered at night > > outside her mother's home which upset the mother thinking someone was > > trying to get in. The daughter though the IR sensor was picking up tree > > branches moving since it is a "motion" detector. I tried to explain that > > the branches were the same temperature and so wouldn't trigger the > > detector. But then I realized, if a strong light were behind the branches > > it might have enough IR to trigger when the branches moved. She didn't see > > the need to involve a light source. > > As I understand it: > > The sensor produces current as its temperature changes. > The pyroelectric element has two cells and the lenses in adjacent > zones of the window focus incoming infrared on opposite cells. > the two signals are fed to opposite inouts of a op-amp and the > amplitude of the output signal is checkedIt’s called a pyroelectric IR sensor: .<https://en.wikipedia.org/wiki/Passive_infrared_sensor> .<https://learn.adafruit.com/pir-passive-infrared-proximity-motion-sensor/how- pirs-work> Joe Gwinn
