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EE版 - 数字电路连接问题请教,实战高手请进
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相关话题的讨论汇总
话题: pir话题: input话题: sensor话题: camera话题: gnd
进入EE版参与讨论
1 (共1页)
m*p
发帖数: 1331
1
最近在捣鼓一个小proj,想用PIR motion sensor和家里的wireless cam连接起来。
PIR用的是这个型号:
http://www.parallax.com/Store/Sensors/ObjectDetection/tabid/176
wireless cam是这个
http://www.scribd.com/doc/29523918/Foscam-us-FI8908W-manual
Alarm Input ArmedInput Pins:
The input pins can be used for 1-way external sensor input. For example, you
mayconnect a Person Infrared Sensor (PIR) to it for motion detection. When
external sensor triggered,IPCAM can be programmed to send an email with
picture or control the internal relay output.If you link a external alarm
with Pin3 and Pin4,when enable alarm input armed,external alarm is enabled.
我按照说明,这样连接:
PIR CAMERA
GND -- GND
VCC -- the PIR DC power
OUT -- INPUT
不是很稳定,有时候能触发,时候不能。PIR已经单独用万用表测过了,works
perfectly.
我拿万用表撤了一下camera的input 和gnd, 居然是5V?!
下一个试验,我用一个1k ohm电阻短接camera的input 和gnd,发现一旦短接,就触发
camera.
根据这样的现象,不知道正确接法应该是怎样的?
谢谢!
g******u
发帖数: 3060
2
so your camera input should be active low? a little weird.
make sure your PIR sensor output is also output low, you may need to invert
the signal.
2nd, make sure everything has enough driving power.
3rd, make sure your sensor can detect at the right distance and range,
sometime those PIR cannot cover all angles, may need some optics design. Try
test right in front of the sensor see if you can trigger the camera every
time.
m*p
发帖数: 1331
3
thanks....
我昨晚反着接,不过不敢弄太久,怕短路了我的camera
这样接的
PIR Camera
GND -- INPUT
Out -- GND
触发了一次,好像也不是很稳定。问题是不好debug,因为camera触发以后要等2min才能
看到结果。。。

invert
Try

【在 g******u 的大作中提到】
: so your camera input should be active low? a little weird.
: make sure your PIR sensor output is also output low, you may need to invert
: the signal.
: 2nd, make sure everything has enough driving power.
: 3rd, make sure your sensor can detect at the right distance and range,
: sometime those PIR cannot cover all angles, may need some optics design. Try
: test right in front of the sensor see if you can trigger the camera every
: time.

m*p
发帖数: 1331
4
pir正常接cam的时候,测了一下camera gnd和input,PIR触发的时候是4.2v, 平时是4.
8v,意味着本来ttl电平偶尔不被触发。。。不知道咋回事。。。
单独测pir的时候,output-gnd平时是0,触发是5v. 这才是对的。不知道camera内部怎
么设计电路的,一接上电位就错了。。。

invert
Try

【在 g******u 的大作中提到】
: so your camera input should be active low? a little weird.
: make sure your PIR sensor output is also output low, you may need to invert
: the signal.
: 2nd, make sure everything has enough driving power.
: 3rd, make sure your sensor can detect at the right distance and range,
: sometime those PIR cannot cover all angles, may need some optics design. Try
: test right in front of the sensor see if you can trigger the camera every
: time.

a****l
发帖数: 8211
5
"The PIR (Passive Infra-Red) Sensor is a pyroelectric device that detects motion by measuring changes in the infrared (heat) levels emitted by surrounding objects. When motion is detected the PIR Sensor outputs a high signal on its output pin. This logic signal can be read by a microcontroller or used to drive an external load. Dual output modes and a sensible design that performs within stated datasheet specifications are a few reasons over 100,000 units are in use around the world."

you
When

【在 m*p 的大作中提到】
: 最近在捣鼓一个小proj,想用PIR motion sensor和家里的wireless cam连接起来。
: PIR用的是这个型号:
: http://www.parallax.com/Store/Sensors/ObjectDetection/tabid/176
: wireless cam是这个
: http://www.scribd.com/doc/29523918/Foscam-us-FI8908W-manual
: Alarm Input ArmedInput Pins:
: The input pins can be used for 1-way external sensor input. For example, you
: mayconnect a Person Infrared Sensor (PIR) to it for motion detection. When
: external sensor triggered,IPCAM can be programmed to send an email with
: picture or control the internal relay output.If you link a external alarm

m*p
发帖数: 1331
6
thanks.
i've tested the PIR itself.
how should i connect to my camera then? thanks.

motion by measuring changes in the infrared (heat) levels emitted by
surrounding objects. When motion is detected the PIR Sensor outputs a high
signal on its output pin. This logic signal can be read by a microcontroller
or used to drive an external load. Dual output modes and a sensible design
that performs within stated datasheet specifications are a few reasons over
100,000 units are in use around the world."

【在 a****l 的大作中提到】
: "The PIR (Passive Infra-Red) Sensor is a pyroelectric device that detects motion by measuring changes in the infrared (heat) levels emitted by surrounding objects. When motion is detected the PIR Sensor outputs a high signal on its output pin. This logic signal can be read by a microcontroller or used to drive an external load. Dual output modes and a sensible design that performs within stated datasheet specifications are a few reasons over 100,000 units are in use around the world."
:
: you
: When

1 (共1页)
进入EE版参与讨论
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相关话题的讨论汇总
话题: pir话题: input话题: sensor话题: camera话题: gnd