project of tracking module using 433MHz RF module

[Prajapati]

Helllo, dear friends i am doing my project given by my college. i am trying to make a tracking module using 433MHz rf module. it is http://robokits.co.in/wireless-solutions/433mhz-rf-transmitter-module-receiver-module-link i want to hide my transmitter at one place and i want to track it from receiver side. on receiver side i want to indicate distance or strength of signal using bunch of LEDs . when it is nearer from transmitter, there will be more number of LEDs will be glow and as we go far away then LED glowing should be decresed. or we can use any type of indicating system. i can not find solution of it. i want your help, please send me a circuit diagram or receiver side adjustable circuit to track transmitter. if it is possible to do this without using microcontroller or programming then it is Best but if is not possible then we can use arduino. plz also suggest programming. i will be thankful, if any one is helping me.

 

[hevans1944]

This is not an appropriate transmitter/receiver pair for what you are trying to do. The transmitter input must be modulated with a low-frequency (200 to 3000 Hz) square wave that the receiver will interpret and respond with a similar square wave output. There is no provision in the receiver to measure the amplitude of the received signal, which is necessary for what you are trying to do. There are also many problems in trying to determine distance based on received signal strength at 433 MH transmit frequency, including reflections from nearby objects, multi-path interference, and directional characteristics of the transmit and receive antennas. You really need at least a three-element Yagi antenna for the receiver and a receiver that provides an output signal proportional to received signal amplitude.

 

[davenn]

Helllo, dear friends i am doing my project given by my college. i am trying to make a tracking module using 433MHz rf module. it is http://robokits.co.in/wireless-solutions/433mhz-rf-transmitter-module-receiver-module-link i want to hide my transmitter at one place and i want to track it from receiver side. on receiver side i want to indicate distance or strength of signal using bunch of LEDs .

Heavens as given you a pretty complete answer, it's not going to happen with what you have chosen and is going to be VERY difficult with other transceiver systems
and distance measurement isn't going to happen without the system being much more complex

Eg. a GPS receiver on the transmitter device and it transmits its location back to the receiver. And a GPS receiver on the receiving system and have software determine the difference in location and thereby giving you a distance between TX and RX. BUT keep in mind that public accessible GPS has an accuracy of around 5 - 10 metres. so even that may be too inaccurate that what you thought you could achieve.
You would have to go with licenced GPS like what I work with and then you can have accuracies of a few mm (millimetres)


Dave

 

[hevans1944]

it's not going to happen with what you have chosen and is going to be VERY difficult with other transceiver systems

I didn't want to bring up possible alternative technology. Anything that actually works (like the dual GPS) will be complicated and expensive. Since this is a college assigned "project" the budget is probably nil. One possible solution would be based on laser range-finding, except using the transmitter RF carrier instead of a visible or infrared laser. This obviously requires co-operation between the transmitter and the receiver (a two-way data link, just like the dual GPS) but a clever person might be able to get it to work using a modulated carrier and sensing carrier modulation phase at the receiver. The OP is not gonna get this done with cheap Asian parts.

 

[Prajapati]

Sir @hevans1944 ,The problem is if i use low frequency 200 to 3000 Hz then it will have problems like more antena height, short transmission range etc. And according to @davenn i can't use GPS because it is expensive.
I just want a indication that my transmitter is somewhat nearer to receiver by glowing LEDS. Sir @hevans1944 what should be the solution? Using laser range finding how we can do that. Please suggest me.

 

[davenn]

The problem is if i use low frequency 200 to 3000 Hz then it will have problems like more antena height, short transmission range etc

what ? transmitter and receiver freq's of 200 - 3000 Hz ?? you are not going to achieve much there either

I just want a indication that my transmitter is somewhat nearer to receiver by glowing LEDS.

you would need to design a receiver around a chip in an experimental band eg the 315 MHz, 433MHz etc that receiver chip would need to have a RSSI output to feed to a signal strength meter

 

[Prajapati]

what ? transmitter and receiver freq's of 200 - 3000 Hz ?? you are not going to achieve much there either



you would need to design a receiver around a chip in an experimental band eg the 315 MHz, 433MHz etc that receiver chip would need to have a RSSI output to feed to a signal strength meter

Yess i need to measure RSSI and give output to signal strength meter . this meter must be in such a way that shows strength in term of glowing LEDs.

 

[davenn]

you would need to do some google searching for receiver IF (Intermediate Frequency) ic's that have that feature

 

[Prajapati]

you would need to do some google searching for receiver IF (Intermediate Frequency) ic's that have that feature

From last several days, continously i am finding solutions but till now i not achieved.

 

[Prajapati]

Sir @hevans1944 and sir @davenn . Yesterday I noticed one situation while doing experiments for my project in lab. as i moved far away from my 433 Mhz transmitter , at receiver side voltage between Antenna pin and Ground pin was changing. means it was 318mv, when it was nearer to rf transmitter. then it was 270mv when we go away, when we moved more far away 150mv we got, means antenna to ground voltage level was decreasing as i go far way.

Now how i can indicate this millivolt change by glowing LEDs. it may need some amplification. how i do it?

 

[Prajapati]

Anyone can help me , i am in need of solution. Plz

 

[phin]

Anyone can help me , i am in need of solution. Plz

Well, it may not be dependable as different environments will get different signal levels and results, but you can use this variation to turn the light on and off. I would take that signal into a buffer/amplifier op-amp. Then to a comparator op-amp with the other input to the comparator being a potentiometer setting the turn on point for the light. The output of the comparator can be used to drive the light. You can find examples of these circuits on-line.

Good luck!

 

[Prajapati]

Well, it may not be dependable as different environments will get different signal levels and results, but you can use this variation to turn the light on and off. I would take that signal into a buffer/amplifier op-amp. Then to a comparator op-amp with the other input to the comparator being a potentiometer setting the turn on point for the light. The output of the comparator can be used to drive the light. You can find examples of these circuits on-line.

Good luck!

Thnxx for ur suggestion @phin I'll try it today. Can i use LM3914 dot/bar display driver to show bunch of LEds?

 

[phin]

Thnxx for ur suggestion @phin I'll try it today. Can i use LM3914 dot/bar display driver to show bunch of LEds?

I suggest you get the basic part working first. The output is a single on/off. But, yes. Set the gain of the buffer amp to cover the range of 0-5 volts output when you provide min to max signal input. This will be the input to the 3914. You may not be impressed with how noisy it seems and may want some filtering. But, first get the basic working to avoid confusion.

 

[Prajapati]

I suggest you get the basic part working first. The output is a single on/off. But, yes. Set the gain of the buffer amp to cover the range of 0-5 volts output when you provide min to max signal input. This will be the input to the 3914. You may not be impressed with how noisy it seems and may want some filtering. But, first get the basic working to avoid confusion.

Thnxx sir @phin for your suggestion.