How Do I Bridge the Connection to Make the PIR Sensor Work?

Look for the schematic. That tells you where the wires go.

We don't do projects, or homework.

Welcome to the real world.

If you have a specific question about a concept or problem, there may be help for you here.

Do you have a diagram of how you have tried to connect the HC-SRO4 ultra sound sensor?

Have you read and understand the specification sheet for this ultra sound detector? This sensor requires a microprocessor to work, which one are you using? Arduino, comes up from any sites that reference this sensor.

There is a trigger signal, that you must provide, to the sensor, they suggest a 10 microsecond pulse. From the back edge of the pulse, the sensor puts out a ranging ultrasound, and then will give a echo pulse on another pin. You must measure the time between these pulses to determine is anything is within range. Hence a processor is needed. You could do this with lots of TTL logic.

Then if something is detected at the range you want, you apply power to your siren or piezo alarm devices.

If this is a "class" project, why are you not being given the guidance needed?

All I can say is read the specifications for each of the devices you are wanting to interface, not the images you inserted, but real specifications.

HC-SR04.pdf

The alarm items can be switched on with "open collector" switches, that will apply ground from your processor development kit. Ask about this once you figure out how to interface the ultra sound ranging unit.

As ignator has said, there has to be some device, usually a microcontroller such as an Arduino, to tell (Trigger) the PIR to fire and to interpret the signal received back (Echo) from the PIR module. He has posted a link to a sheet telling how this works. Here's a link to a wiring diagram. But after the wiring hook-up is made, the Arduino must be programmed to perform the communications to and from the PIR module and to control some output pin(s) to 'tell' you what it found (via some device connected to the output pin). To start with, I'd use a simple LED and resistor on the output. I suspect you know that the output devices you show require higher voltage (and current) than the Arduino can provide. After you get the basic function working with a simple LED, you can worry about how to use the small signal to control more power. There is a lot of information available by Google'ing 'HC-SR04'. Good luck and feel free to post your results and any more questions.

It just occurred to me that the HC-SR04 module is an ultrasonic ranging module, not a PIR (passive infrared) detector. ignator also stated this, but I just wanted to make sure you knew.

/* HC-SR04 Ping distance sensor: VCC to arduino 5v GND to arduino GND Echo to Arduino pin 7 Trig to Arduino pin 8 This sketch originates from Virtualmix: http://goo.gl/kJ8Gl Has been modified by Winkle ink here: http://winkleink.blogspot.com.au/2012/05/arduino-hc-sr04-ultrasonic-distance.html And modified further by ScottC here: http://arduinobasics.blogspot.com/ on 10 Nov 2012. */ #define echoPin 7 // Echo Pin #define trigPin 8 // Trigger Pin #define LEDPin 13 // Onboard LED int maximumRange = 200; // Maximum range needed int minimumRange = 0; // Minimum range needed long duration, distance; // Duration used to calculate distance void setup() { Serial.begin (9600); pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT); pinMode(LEDPin, OUTPUT); // Use LED indicator (if required) } void loop() { /* The following trigPin/echoPin cycle is used to determine the distance of the nearest object by bouncing soundwaves off of it. */ digitalWrite(trigPin, LOW); delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); duration = pulseIn(echoPin, HIGH); //Calculate the distance (in cm) based on the speed of sound. distance = duration/58.2; if (distance >= maximumRange || distance <= minimumRange){ /* Send a negative number to computer and Turn LED ON to indicate "out of range" */ Serial.println("-1"); digitalWrite(LEDPin, HIGH); } else { /* Send the distance to the computer using Serial protocol, and turn LED OFF to indicate successful reading. */ Serial.println(distance); digitalWrite(LEDPin, LOW); } //Delay 50ms before next reading. delay(50); }

PIR sensor need to be properly mounted to let it sense.

It has two sensors in parallel || and if you rotate then by 90 degree then it simply can't sense anything.

You also need to make sure that IR lens is on top of the PIR sensor. It is usually translucent dome type and sometime cylindrical.

Output of the sensor may be TTL or relay output. There must be some instructions, in the catalog to connect an external alarm.

HI, First of all, the sensor you are using is an ultra-sonic sensor as Bigg has pointed out.

A PIR (passive infrared sensor) Sensor would be a whole lot easier to set up and program. Check them out at: www.sparkfun.com/products/8630

May the force be with you

Cheers Joe

As someone said, its not PIR its ultrasonic.....

That said (please ask if there is anything you don't understand!):-

You could use a high resistance 3 volt relay connected to the echo (+) output and ground. Do put a reversed relay across the coil to stop back EMF from damaging the Ultrasonic unit.

I don't know what the available output current is though. Though its badly designed if it cannot drive directly a relay.

If the pulsing is a problem, then connect a 1µf Polarised cap across the echo and ground. Add more caps in parallel if the pulsing is still too much.

Add a resistor in series if you need to make the relay more sensitive, start with a resistor of the same value as the relay coil.

The method I prefer myself is to use a PICAXE BASIC programmed PIC to receive the pulses and to control the siren via a transistor.

The software for PICAXE chips and all the books and Tutorials are free to download from here:-

http://www.rev-ed.co.uk/

They chips themselves may be also available locally to you for a few US$$ only. All very cheap!!

They cover simple interfacing with a transistor for either input or output as well with diagrams in the manuals.

You only need the smallest and cheapest PICAXE chip, post and packing will cost more! But also buy the experimenters kit from here:-

http://www.techsupplies.co.uk/epages/Store.sf?ObjectPath=/Shops/Store.TechSupplies

The experimenters kit itself is here:-

http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Products/AXE091U

Best of luck.

Hi Mate,

You need to interface this with a PIC, go to www.picaxe.co.uk, they have loads of useful literature there. If you order a PIC from them they bootstrap them so it is as easy as 123 to program, they have everything you need to know on this site.

Good luck, -Rob.

So you fully agree with me about PICAXEs then (see previous post to yours) as being a good way to fix the problems he is having!

They are used far less frequently than they should be I feel, though I do not consider myself to be an expert in any way shape or form on ANY PIC device....

They save a massive amount of conventional logic design and chips and can be reprogrammed many, many times till something works just right!!!

"In situ" as well if correctly designed, or can be simply popped out of a socket if not!!

I fully agree Andy,

I have done amazing things with PICs, if you make your own board with relay outputs (Transistors to drive the coils) you can make up a mini PLC and it is a lot of fun!!!

Here is a transistor output board I made a long time ago for a mate in a casino (Coin Pusher Alarm)